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Table of Contents

Administration Guide

Configuring an HTTP server policy

Configure HTTP server policies by combining your rules, profiles, and sub-policies.

Server policies:

  • Block or allow connections
  • Apply a protection profile that specifies how FortiWeb scans or processes the HTTP/HTTPS requests that it allows
  • Route or let pass traffic to destination web servers

Until you configure and enable at least one policy, FortiWeb will, by default:

  • when in Reverse Proxy mode, deny all traffic.
  • when in other operation modes, allow all traffic.

Server policy behavior and supported features vary by operation mode. For details, see How operation mode affects server policy behavior. It also varies by whether or not the policy uses IPv6 addresses.

To achieve more complex policy behaviors and routing, you can chain multiple policies together. For details, see Defining your web servers.

Do not configure policies you will not use. FortiWeb allocates memory with each server policy, regardless of whether it is actually in active use. Configuring extra policies unnecessarily consumes memory and decreases performance.

Certain server policy options are only available in CLI. You might not want to skip them because they may be useful for some cases. For example, to mitigate low&slow attacks, you can set http-header-timeout and tcp-recv-timeout to specify the timeout for the HTTP header and TCP request sent from clients.

For a full set of the server policy options, see config server-policy policy in FortiWeb CLI Reference Guide.

 

If a policy has any virtual servers or a server pool members with IPv6 addresses, it does not apply features that do not yet support IPv6, even if they are selected.
To configure a policy
  1. Before you configure a policy, you usually should first configure any of the following that you must, or want to, include in the policy:
  2. Alternatively, you can create missing components on-the-fly while configuring the policy, without leaving the page. To do this, select Create New from each policy component’s drop-down menu.

    However, when creating many components, you can save time by leaving the policy page, going to the other menu areas, and creating similar profiles by cloning, then modifying each clone.

    Generally speaking, because policies tie other components together and apply them to client’s connections with your web servers, they should be configured last. For details, see Workflow.

  • Go to Policy > Server Policy.
  • To access this part of the web UI, your administrator account’s access profile must have Read and Write permission to items in the Server Policy Configuration category. For details, see Permissions.

  • Click Create New.
  • Configure the following settings.
  • The operation mode and Deployment Mode value determine which options are available.

    Policy Name Type a name that can be referenced by other parts of the configuration. The maximum length is 63 characters.
    Deployment Mode

    Select the method of distribution that the FortiWeb appliance uses when it accepts connections for this policy.

    The deployment modes that are available depend on the types of network topologies that the current operation mode supports.

    • Single Server/Server Balance—Forwards connections to a server pool. Depending on the pool configuration, FortiWeb either forwards connections to a single physical server or domain server or distributes the connection among the pool members. Also configure a Server Pool . This option is available only in Reverse Proxy mode.
    • HTTP Content Routing—Use HTTP content routing to route HTTP requests to a specific server pool. This option is available only in Reverse Proxy mode.

    Note: When HTTP Content Routing is selected, FortiWeb can handle HTTP/2 client requests, but traffic from FortiWeb to the server(s) must use HTTP, so the HTTP/2 setting in a server pool configuration would have to remain disabled. For details, see Defining your web servers.

    • Offline Protection—Allow connections to pass through the FortiWeb appliance, and apply an Offline Protection profile. Also configure a Server Pool . This option is available only in Offline Protection mode.
    • Transparent Servers—Allow connections to pass through the FortiWeb appliance, and apply a protection profile. Also configure a Server Pool . This option is available only in True Transparent Proxy or Transparent Inspection mode.
    • WCCP ServersFortiWeb will act as a Web Cache Communication Protocol (WCCP) client that receives traffic from a FortiGate configured as a WCCP server. Also configure a Server Pool . This option is available only in WCCP mode.

    Virtual Server

    or

    Data Capture Port

    or

    V-zone

    Select the name of a virtual server, data capture (listening) network interface, or v-zone (bridge) according to the operation mode:

    The name and purpose of these settings varies by operation mode:

    • Virtual Server—Identifies the IP address and network interface of incoming traffic that FortiWeb routes and that the policy applies a profile to. This option is available only in Reverse Proxy mode.

    • Data Capture Port—Identifies the network interface of incoming traffic that the policy applies a profile to. The IP address is ignored. This option is available only in Offline Protection mode.

      If your FortiWeb model uses Data Plane Development Kit (DPDK) for packet processing (e.g., models 3000E, 3010E and 4000E), this option has the following limitations:

      • Only physical interfaces can be data capture ports. These models do not support VLAN subinterfaces or link aggregate interfaces as data capture ports.
      • You cannot edit the interface after you set it as a data capture port. If you need to configure the maximum transmission unit (MTU) for the interface (using the config system interface and config system v-zone CLI commands), do it before you select the interface as a data capture port.
    • V-zone—Identifies the network interface of the incoming traffic that the policy applies a profile to. This option is available in True Transparent Proxy and Transparent Inspection mode.
    HTTP Content Routing

    To specify HTTP content routing policies and options that this policy uses, click Add, then complete the following settings for each entry:

    • HTTP Content Routing Policy Name—The name of the policy.
    • Inherit Web Protection Profile—Specify whether FortiWeb applies the web protection profile for the server policy to connections that match the routing policy.
    • Web Protection Profile—Select the profile to apply to connections that match the routing policy. For details, see Configuring a protection profile for inline topologies.

      Note: FortiWeb does not block clients with source IP addresses designated as a trusted IP. For details, see Blacklisting & whitelisting clients using a source IP or source IP range.

    • Default—Specifies whether FortiWeb applies the specified protection profile to any traffic that does not match any HTTP content routing policy in the list.

    You can specify up to 256 HTTP content routing policies in each server policy.

    This option is available only in Reverse Proxy mode and when the Deployment Mode is HTTP Content Routing.

    Match Once

    Enable to forward subsequent requests from an identified client connection to the same server pool as the initial connection from the client.

    This option allows FortiWeb to improve its performance by skipping the process of matching HTTP header content to content routing policies for connections it has already evaluated and routed.

    This option is available only in Reverse Proxy mode and when the Deployment Mode is HTTP Content Routing.

    Server Pool

    Select the server pool whose members receive the connections. A server pool can contain a single physical server or domain server. For details, see Creating a server pool.

    This option is available only if the Deployment Mode is Single Server/Server Pool, Offline Protection, Transparent Server, or WCCP Servers.

    Caution: Multiple virtual servers/policies can forward traffic to the same server pool. If you do this, consider the total maximum load of connections that all virtual servers forward to your server pool. This configuration can multiply traffic forwarded to your server pool, which can overload them and cause dropped connections.

    Protected Hostnames

    Select a protected host names group to allow or reject connections based upon whether the Host: field in the HTTP header is empty or does or does not match the protected host names group. For details, see Defining your protected/allowed HTTP “Host:” header names.

    If you do not select a protected host names group, FortiWeb accepts or blocks requests based on other criteria in the policy or protection profile, but will not accept or block requests based on the Host: field in the HTTP header.

    Attack log messages contain HTTP Host Violation when this feature detects a hostname that is not allowed..

    Caution: Unlike HTTP 1.1, HTTP 1.0 does not require the Host: field. The FortiWeb appliance does not block HTTP 1.0 requests because they do not have this field, regardless of whether or not you have selected a protected host names group.

    Client Real IP

    By default, when the operation mode is Reverse Proxy, the source IP for connections between FortiWeb and back-end servers is the address of a FortiWeb network interface.

    If you enable Client Real IP, FortiWeb will use the source IP address of the client that originated the request when it connects to a back-end server on behalf of that client. This option is available only in Reverse Proxy mode.

    If you set the server's IP address as the source address in a policy route, it is recommended that you do not enable Client Real IP, otherwise it may cause your application inaccessible.

    Note: To ensure FortiWeb receives the server's response when you enable Client Real IP, configure FortiWeb as the server’s gateway.

    Blocking Port

    Select which network interface FortiWeb uses to send TCP RST (connection reset) packets when it attempts to block the request or connection after it detects traffic that violates a policy. For details on blocking behavior, see Topology for Offline Protection mode.

    This option is available only in Offline Protection mode.

    Syn Cookie

    Enable to prevent TCP SYN floods. Also configure Half Open Threshold.

    For details, see Preventing a TCP SYN flood.

    This option is available only in Reverse Proxy, True Transparent Proxy, and WCCP mode.

    Half Open Threshold

    Type the TCP SYN cookie threshold in packets per second. Also configure Syn Cookie.

    Available only when the operating mode is Reverse Proxy, True Transparent Proxy, or WCCP.

    HTTP Service

    Select the custom or predefined service that defines the TCP port number where the virtual server receives HTTP traffic.

    This option is available only in Reverse Proxy mode.

    HTTPS Service

    Select the custom or predefined service that defines the TCP port number where the virtual server receives HTTPS traffic. Also configure Certificate.

    Enable if requests from clients to the FortiWeb appliance or back-end servers use SSL or TLS. See also Supported cipher suites & protocol versions.

    When enabled, the FortiWeb appliance handles SSL negotiations and encryption and decryption, instead of the web servers, also known as SSL offloading. For details, see Offloading vs. inspection.

    Connections between the client and the FortiWeb appliance are encrypted. The server pool configuration specifies whether connections between the FortiWeb appliance and each web server are encrypted.

    This option is available only in Reverse Proxy mode. For other operation modes, use the server pool configuration to enable SSL inspection. For details, see Creating a server pool.

    Caution: If you do not enable an HTTPS option and provide a certificate for HTTPS connections, FortiWeb cannot decrypt connections and scan content in the HTTP body.

    Tip: FortiWeb appliances contain specialized hardware to accelerate SSL processing. Offloading SSL/TLS processing can improve the performance of secure HTTP (HTTPS) connections.

    HTTP/2

    Enable FortiWeb to negotiate HTTP/2 with clients via SSL ALPN (Application-Layer Protocol Negotiation) during the SSL handshake if the client's browser supports the HTTP/2 protocol. If HTTP/2 is enabled, FortiWeb will recognize HTTP/2 traffic and apply the security services to it.

    Note: This option is available only if the Deployment Mode is Single Server/Server Pool or HTTP Content Routingand HTTPS Service is configured correctly. This is because FortiWeb supports HTTP/2 only for HTTPS connections. Please keep in mind that if the Deployment Mode is HTTP Content Routing, client requests can use HTTP/2, but traffic between FortiWeb and the server(s) must use HTTP, so the HTTP/2 setting in a server pool configuration would have to remain disabled. For details, see Defining your web servers.

    To configure HTTP/2 in True Transparent Proxy mode, see HTTP/2 support

    Enable Multi-certificate Enable this option to allow FortiWeb to use multiple local certificates.
    Multi-certificate Select the local server certificate created in System > Certificates > Multi-certificate that FortiWeb uses to encrypt or decrypt SSL-secured connections for the website specified by Configuring an HTTP server policy. For details, see Configuring an HTTP server policy.
    Certificate

    Select the server certificate that FortiWeb uses to encrypt or decrypt SSL-secured connections.

    For details, see Uploading a server certificate and Offloading vs. inspection.

    If Enable Server Name Indication (SNI) is selected, FortiWeb uses a Server Name Indication (SNI) configuration instead of or in addition to this server certificate.

    Available only if you specify a value for HTTPS Service.

    Certificate Intermediate Group

    Select the name of a group of intermediate certificate authority (CA) certificates, if any, that FortiWeb presents to clients. An intermediate CA can complete the signing chain and validate the server certificate’s CA signature.

    Configure this option when clients receive certificate warnings that an intermediary CA has signed the server certificate specified by the selected Certificate, not a root CA or other CA currently trusted by the client directly.

    Alternatively, you can include the entire signing chain in the server certificate itself before you upload it to FortiWeb. For details, see Uploading a server certificate and Supplementing a server certificate with its signing chain.

    Available only if you specify a value for HTTPS Service.

    Show/Hide advanced SSL settings

    Click to show or hide the settings that allow you to specify a Server Name Indication (SNI) configuration, increase security by disabling specific versions of TLS and SSL for this policy, and other advanced SSL settings.

    For example, if FortiWeb can use a single certificate to decrypt and encrypt traffic for all the websites that reside on the servers in a pool, you may not have to set any advanced SSL settings.

    Available only if you specify a value for HTTPS Service.

    Add HSTS Header

    Enable to combat MITM attacks on HTTP by injecting the RFC 6797 (http://tools.ietf.org/html/rfc6797) strict transport security header into the reply. For example:

    Strict-Transport-Security: max-age=31536000

    This header forces clients to use HTTPS for subsequent visits to this domain. If the certificate is invalid, the client’s web browser receives a fatal connection error and does not display a dialog that allows the user to override the certificate mismatch error and continue.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Max. Age

    Specify the time to live in seconds for the HSTS header.

    Available only if Add HSTS Header is selected.

    Add HPKP Header

    Select an HPKP profile, if any, to use to verify certificates when clients attempt to access a server.

    HPKP prevents attackers from carrying out Man in the Middle (MITM) attacks with forged certificates. For details, see HTTP Public Key Pinning.

    Available only if you specify a value for HTTPS Service.

    Certificate Verification

    Select the name of a certificate verifier, if any, that FortiWeb uses to validate an HTTP client’s personal certificate.

    Personal certificates, sometimes also called user certificates, establish the identity of the person connecting to the website (PKI authentication). If a User Tracking Policy or Site Publish rule fails to track a user, FortiWeb will attempt to track a user with his or her email address provided in the client certificate via Certificate Verification.

    You can require clients to present a certificate instead of, or in addition to, HTTP authentication. For details, see Offloading HTTP authentication & authorization.

    Available only if you specify a value for HTTPS Service.

    For True Transparent Proxy mode, configure this setting in the server pool configuration instead. For details, see Certificate Verification.

    Note: The client must support TLS 1.0, TLS 1.1, TLS 1.2, and TLS 1.3.

    If you select Enable Server Name Indication (SNI) and the domain in the client request matches an entry in the specified SNI policy, FortiWeb uses the SNI configuration to determine which certificate verifier to use instead.

    If you do not select a verifier, clients are not required to present a personal certificate. For details, see How to apply PKI client authentication (personal certificates).

    Enable URL Based Client Certificate

    Specifies whether FortiWeb uses a URL-based client certificate group to determine whether a client is required to present a personal certificate.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Note: This function is not supported for HTTP/2 communication between the Client and this back-end web server.

    URL Based Client Certificate Group

    Specifies the URL-based client certificate group that determines whether a client is required to present a personal certificate.

    If the URL the client requests does not match an entry in the group, the client is not required to present a personal certificate.

    For information on creating a group, see Use URLs to determine whether a client is required to present a certificate.

    Available only if Enable URL Based Client Certificate is selected.

    Max HTTP Request Length

    Specifies the maximum allowed length for an HTTP request with a URL that matches an entry in the URL-based client certificate group.

    FortiWeb blocks any matching requests that exceed the specified size.

    This setting prevents a request from exceeding the maximum buffer size.

    Available only if Enable URL Based Client Certificate is selected.

    Client Certificate Forwarding

    Enable to configure FortiWeb to include the X.509 personal certificate presented by the client during the SSL/TLS handshake, if any, in an X-Client-Cert: HTTP header when it forwards the traffic to the protected web server.

    FortiWeb still validates the client certificate itself, but this forwarding action can be useful if the web server requires the client certificate for server-side identity-based functionality

    Note: It is necessary to set Certificate Verification to make this option effective.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Custom Header of CCF Subject

    Enter a custom subject header that will be inserted in the X.509 personal certificate presented by the client during the SSL/TLS handshake.

    Available only if Client Certificate Forwarding is selected.

    Customer Header of CCF Certificate

    Enter a custom certificate header that will be inserted in the X.509 personal certificate presented by the client during the SSL/TLS handshake.

    Available only if Client Certificate Forwarding is selected.

    Enable Server Name Indication (SNI)

    Select to use a Server Name Indication (SNI) configuration instead of or in addition to the server certificate specified by the Certificate.

    The SNI configuration enables FortiWeb to determine which certificate to present on behalf of the members of a pool based on the domain in the client request. For details, see Allowing FortiWeb to support multiple server certificates.

    If you specify both an SNI configuration and Certificate, FortiWeb uses the certificate specified by Certificate when the requested domain does not match a value in the SNI configuration.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Enable Strict SNI

    Select so that FortiWeb will ignore the Certificate when it determines which certificate to present on behalf of server pool members, even if the domain in a client request does not match a value in the SNI configuration.

    Available only if Enable Server Name Indication (SNI) is selected.

    SNI Policy

    Select the Server Name Indication (SNI) configuration that determines which certificate FortiWeb presents on behalf of the members of a server pool.

    Available only if Enable Server Name Indication (SNI) is selected.

    SSL Protocols

    Specify which versions of the SSL or TLS cryptographic protocols clients can use to connect securely to the FortiWeb appliance.

    TLS protocol changes a lot since version 1.3, including the handshake algorithm, the supported ciphers and certificates. Make sure you understand how it works before enabling TLS 1.3.

    Note: O-RTT in TLS 1.3 is disabled by default. You can use the following command to enable it:

    config server-policy setting

    set tls13-early-data-mode enable

    end

    For the supported ciphers of each TLS version, see Supported cipher suites & protocol versions.

    This option is available when:

    For details, see Supported cipher suites & protocol versions.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    SSL/TLS encryption level

    Specify whether the set of cipher suites that FortiWeb allows creates a medium-security, high-security or customized security configuration.

    If you select Customized, you can select a cipher and then use the arrow keys to move it to the appropriate list.

    For details, see Supported cipher suites & protocol versions.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Disable Client-Initiated SSL Renegotiation

    Select to configure FortiWeb to ignore requests from clients to renegotiate TLS or SSL.

    Protect against denial-of-service (DoS) attacks that use TLS/SSL renegotiation to overburden the server.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Proxy Protocol

    Enable this option when proxy servers or load balancers are installed before FortiWeb, for example, when a load balancer with proxy protocol enabled is deployed before FortiWeb-VM on AWS.

    When Proxy Protocol is enabled, FortiWeb can receive client connection information in the proxy protocol package passed through proxy servers and load balancers.

    Redirect HTTP to HTTPS

    Select to automatically redirect all HTTP requests to the HTTPS service with the same URL and parameters. If you select this option, ensure to configure HTTPS Service.

    If selected, FortiWeb does not apply the protection profile for this policy specified by the Web Protection Profile to the redirected traffic.

    This option can replace redirection functionality that you create using URL rewriting rules. For details, see Example: HTTP-to-HTTPS redirect.

    This option is available only in Reverse Proxy mode.

    Web Protection Profile

    Select the profile to apply to the connections that this policy accepts, or select Create New to add a new profile in a pop-up window, without leaving the current page.

    For details on specific protection profiles, see one of the following topics:

    Note: The current operation mode determines which profiles are available. For details, see How operation mode affects server policy behavior.

    Note: FortiWeb does not block clients with source IP addresses designated as a trusted IP. For details, see Blacklisting & whitelisting clients using a source IP or source IP range.

    If the Deployment Mode is set to HTTP Content Routing, this option is effective when you create the list of content routing policies.

    Replacement Message

    Select the replacement message to apply to the policy.

    View Profile Details

    Click to display the settings of the current profile without leaving the current page. When viewing a profile, you can also modify its settings from here.

    To return to the policy settings, click Back to Policy Settings.

    Monitor Mode

    Enable to override any actions included in the profiles. Instead, FortiWeb will accept all requests and generate an alert email and/or log message for all policy violations.

    This setting does not affect any rewriting or redirection actions in the protection profiles, including the action to remove poisoned cookies.

    Note: Logging and/or alert email occur only if you enable and configure them. For details, see Logging and Alert email.

    URL Case Sensitivity

    Enable to differentiate uniform resource locators (URLs) according to upper case and lower case letters for features that act upon the URLs in the headers of HTTP requests, such as start page rules, IP list rules, and page access rules.

    For example, when this option is enabled, an HTTP request involving http://www.Example.com/ would not match profile features that specify http://www.example.com (difference is lower case “e”).

    Comments Type a description or other comment. The description can be up to 999 characters long.
  • Click OK.
  • The server policy is displayed in the list on Policy > Server Policy. Initially, it is enabled. For details on disabling a policy without deleting it, see Enabling or disabling a policy.

    Legitimate traffic should now be able to flow, while policy-violating traffic (that is, traffic that is prohibited by the settings in your policy or protection profile) may be blocked, depending on your Action settings for the rule that the traffic has violated.

    Whitelisted items are not included in policy enforcement. For details, see Configuring the global object white list.

  • To verify the policy, test it by forming connections between legitimate clients and servers at various points within your network topology. Also attempt to send traffic that violates your policy, and should be logged, modified, or blocked.
  • If you have another FortiWeb appliance, you can use its web vulnerability scanner to verify that your policy is blocking attacks as you expect. For details, see Vulnerability scans.

    If a connection fails, you can use tools included in the firmware to determine whether the problem is local to the appliance or elsewhere on the network. For details, see Troubleshooting and Reducing false positives. Also consider troubleshooting recommendations included with each feature’s instructions.

    See also

    HTTP pipelining

    For clients that support HTTP 1.1, FortiWeb accelerates transactions by bundling them inside the same TCP connection, instead of waiting for a response before sending/receiving the next request. This can increase performance when pages containing many images, scripts, and other auxiliary files are all hosted on the same domain, and therefore logically could use the same connection.

    Many browsers used on smart phones prefer to pipeline their HTTP requests.

    When FortiWeb is operating in Reverse Proxy or True Transparent Proxy mode, it can automatically use HTTP pipelining for requests with the following characteristics:

    • HTTP version is 1.1
    • The Connection general-header field does not include the "close" option (for example, Connection: close)
    • The HTTP method is GET or HEAD

    Although it is enabled by default, you can use a CLI command to disable or re-enable HTTP pipelining for a specific server policy.

    To disable or enable HTTP pipelining
    1. Connect to the CLI.
    2. In each policy that requires it, enter these commands:

    config server-policy policy

    edit <policy_name>

    set http-pipeline {enable | disable}

    next

    end

     

    For details, see the FortiWeb CLI Reference:

    http://docs.fortinet.com/fortiweb/reference

    See also

    Multiplexing client connections

    By default, FortiWeb establishes a connection with the server for each client that makes a request to the server. When a client makes a request, FortiWeb creates a connection to the server for that client's request. If a second client makes a request, FortiWeb creates another connection to the server for the second client's request.

    You can configure multiplexing so that FortiWeb uses a single connection to a server for requests from multiple clients. If multiplexing is configured, when a client makes a request, FortiWeb establishes a connection to the server for that client's request. Once the request has been completed, FortiWeb caches the connection. If a second client then makes a request to the server, FortiWeb uses the cached connection for the second client's request. You can configure the circumstances in which FortiWeb caches a server connection and reuses it for requests from other clients.

    To configure multiplexing
    1. Connect to the CLI.
    2. In each policy that requires it, enter these commands:

    config server-policy server-pool

    edit <server_pool_name>

    set http-reuse {aggressive | always | never | safe}

    set reuse-conn-idle-time <int>

    set reuse-conn-max-count <int>

    set reuse-conn-max-request <int>

    set reuse-conn-total-time <int>

    next

    end

     

    For details, see the FortiWeb CLI Reference:

    http://docs.fortinet.com/fortiweb/reference

    Enabling or disabling a policy

    You can individually enable and disable policies.

    When the operation mode is Reverse Proxy, disabling a policy could block traffic if no remaining active policies match that traffic. When no policies exist or none are enabled, the FortiWeb appliance blocks all HTTP/HTTPS traffic.

    Even if you disable a server policy, it still consumes memory (RAM). If you do not plan to use the policy for some time, consider deleting it instead.

    To enable or disable a policy
    1. Go to Policy > Server Policy.
    2. In the row corresponding to the policy that you want to enable, click the switch on in the Enable column.
    3. In the row corresponding to the policy that you want to disable, click the switch off in the Enable column.

    Configuring an HTTP server policy

    Configure HTTP server policies by combining your rules, profiles, and sub-policies.

    Server policies:

    • Block or allow connections
    • Apply a protection profile that specifies how FortiWeb scans or processes the HTTP/HTTPS requests that it allows
    • Route or let pass traffic to destination web servers

    Until you configure and enable at least one policy, FortiWeb will, by default:

    • when in Reverse Proxy mode, deny all traffic.
    • when in other operation modes, allow all traffic.

    Server policy behavior and supported features vary by operation mode. For details, see How operation mode affects server policy behavior. It also varies by whether or not the policy uses IPv6 addresses.

    To achieve more complex policy behaviors and routing, you can chain multiple policies together. For details, see Defining your web servers.

    Do not configure policies you will not use. FortiWeb allocates memory with each server policy, regardless of whether it is actually in active use. Configuring extra policies unnecessarily consumes memory and decreases performance.

    Certain server policy options are only available in CLI. You might not want to skip them because they may be useful for some cases. For example, to mitigate low&slow attacks, you can set http-header-timeout and tcp-recv-timeout to specify the timeout for the HTTP header and TCP request sent from clients.

    For a full set of the server policy options, see config server-policy policy in FortiWeb CLI Reference Guide.

     

    If a policy has any virtual servers or a server pool members with IPv6 addresses, it does not apply features that do not yet support IPv6, even if they are selected.
    To configure a policy
    1. Before you configure a policy, you usually should first configure any of the following that you must, or want to, include in the policy:
    2. Alternatively, you can create missing components on-the-fly while configuring the policy, without leaving the page. To do this, select Create New from each policy component’s drop-down menu.

      However, when creating many components, you can save time by leaving the policy page, going to the other menu areas, and creating similar profiles by cloning, then modifying each clone.

      Generally speaking, because policies tie other components together and apply them to client’s connections with your web servers, they should be configured last. For details, see Workflow.

  • Go to Policy > Server Policy.
  • To access this part of the web UI, your administrator account’s access profile must have Read and Write permission to items in the Server Policy Configuration category. For details, see Permissions.

  • Click Create New.
  • Configure the following settings.
  • The operation mode and Deployment Mode value determine which options are available.

    Policy Name Type a name that can be referenced by other parts of the configuration. The maximum length is 63 characters.
    Deployment Mode

    Select the method of distribution that the FortiWeb appliance uses when it accepts connections for this policy.

    The deployment modes that are available depend on the types of network topologies that the current operation mode supports.

    • Single Server/Server Balance—Forwards connections to a server pool. Depending on the pool configuration, FortiWeb either forwards connections to a single physical server or domain server or distributes the connection among the pool members. Also configure a Server Pool . This option is available only in Reverse Proxy mode.
    • HTTP Content Routing—Use HTTP content routing to route HTTP requests to a specific server pool. This option is available only in Reverse Proxy mode.

    Note: When HTTP Content Routing is selected, FortiWeb can handle HTTP/2 client requests, but traffic from FortiWeb to the server(s) must use HTTP, so the HTTP/2 setting in a server pool configuration would have to remain disabled. For details, see Defining your web servers.

    • Offline Protection—Allow connections to pass through the FortiWeb appliance, and apply an Offline Protection profile. Also configure a Server Pool . This option is available only in Offline Protection mode.
    • Transparent Servers—Allow connections to pass through the FortiWeb appliance, and apply a protection profile. Also configure a Server Pool . This option is available only in True Transparent Proxy or Transparent Inspection mode.
    • WCCP ServersFortiWeb will act as a Web Cache Communication Protocol (WCCP) client that receives traffic from a FortiGate configured as a WCCP server. Also configure a Server Pool . This option is available only in WCCP mode.

    Virtual Server

    or

    Data Capture Port

    or

    V-zone

    Select the name of a virtual server, data capture (listening) network interface, or v-zone (bridge) according to the operation mode:

    The name and purpose of these settings varies by operation mode:

    • Virtual Server—Identifies the IP address and network interface of incoming traffic that FortiWeb routes and that the policy applies a profile to. This option is available only in Reverse Proxy mode.

    • Data Capture Port—Identifies the network interface of incoming traffic that the policy applies a profile to. The IP address is ignored. This option is available only in Offline Protection mode.

      If your FortiWeb model uses Data Plane Development Kit (DPDK) for packet processing (e.g., models 3000E, 3010E and 4000E), this option has the following limitations:

      • Only physical interfaces can be data capture ports. These models do not support VLAN subinterfaces or link aggregate interfaces as data capture ports.
      • You cannot edit the interface after you set it as a data capture port. If you need to configure the maximum transmission unit (MTU) for the interface (using the config system interface and config system v-zone CLI commands), do it before you select the interface as a data capture port.
    • V-zone—Identifies the network interface of the incoming traffic that the policy applies a profile to. This option is available in True Transparent Proxy and Transparent Inspection mode.
    HTTP Content Routing

    To specify HTTP content routing policies and options that this policy uses, click Add, then complete the following settings for each entry:

    • HTTP Content Routing Policy Name—The name of the policy.
    • Inherit Web Protection Profile—Specify whether FortiWeb applies the web protection profile for the server policy to connections that match the routing policy.
    • Web Protection Profile—Select the profile to apply to connections that match the routing policy. For details, see Configuring a protection profile for inline topologies.

      Note: FortiWeb does not block clients with source IP addresses designated as a trusted IP. For details, see Blacklisting & whitelisting clients using a source IP or source IP range.

    • Default—Specifies whether FortiWeb applies the specified protection profile to any traffic that does not match any HTTP content routing policy in the list.

    You can specify up to 256 HTTP content routing policies in each server policy.

    This option is available only in Reverse Proxy mode and when the Deployment Mode is HTTP Content Routing.

    Match Once

    Enable to forward subsequent requests from an identified client connection to the same server pool as the initial connection from the client.

    This option allows FortiWeb to improve its performance by skipping the process of matching HTTP header content to content routing policies for connections it has already evaluated and routed.

    This option is available only in Reverse Proxy mode and when the Deployment Mode is HTTP Content Routing.

    Server Pool

    Select the server pool whose members receive the connections. A server pool can contain a single physical server or domain server. For details, see Creating a server pool.

    This option is available only if the Deployment Mode is Single Server/Server Pool, Offline Protection, Transparent Server, or WCCP Servers.

    Caution: Multiple virtual servers/policies can forward traffic to the same server pool. If you do this, consider the total maximum load of connections that all virtual servers forward to your server pool. This configuration can multiply traffic forwarded to your server pool, which can overload them and cause dropped connections.

    Protected Hostnames

    Select a protected host names group to allow or reject connections based upon whether the Host: field in the HTTP header is empty or does or does not match the protected host names group. For details, see Defining your protected/allowed HTTP “Host:” header names.

    If you do not select a protected host names group, FortiWeb accepts or blocks requests based on other criteria in the policy or protection profile, but will not accept or block requests based on the Host: field in the HTTP header.

    Attack log messages contain HTTP Host Violation when this feature detects a hostname that is not allowed..

    Caution: Unlike HTTP 1.1, HTTP 1.0 does not require the Host: field. The FortiWeb appliance does not block HTTP 1.0 requests because they do not have this field, regardless of whether or not you have selected a protected host names group.

    Client Real IP

    By default, when the operation mode is Reverse Proxy, the source IP for connections between FortiWeb and back-end servers is the address of a FortiWeb network interface.

    If you enable Client Real IP, FortiWeb will use the source IP address of the client that originated the request when it connects to a back-end server on behalf of that client. This option is available only in Reverse Proxy mode.

    If you set the server's IP address as the source address in a policy route, it is recommended that you do not enable Client Real IP, otherwise it may cause your application inaccessible.

    Note: To ensure FortiWeb receives the server's response when you enable Client Real IP, configure FortiWeb as the server’s gateway.

    Blocking Port

    Select which network interface FortiWeb uses to send TCP RST (connection reset) packets when it attempts to block the request or connection after it detects traffic that violates a policy. For details on blocking behavior, see Topology for Offline Protection mode.

    This option is available only in Offline Protection mode.

    Syn Cookie

    Enable to prevent TCP SYN floods. Also configure Half Open Threshold.

    For details, see Preventing a TCP SYN flood.

    This option is available only in Reverse Proxy, True Transparent Proxy, and WCCP mode.

    Half Open Threshold

    Type the TCP SYN cookie threshold in packets per second. Also configure Syn Cookie.

    Available only when the operating mode is Reverse Proxy, True Transparent Proxy, or WCCP.

    HTTP Service

    Select the custom or predefined service that defines the TCP port number where the virtual server receives HTTP traffic.

    This option is available only in Reverse Proxy mode.

    HTTPS Service

    Select the custom or predefined service that defines the TCP port number where the virtual server receives HTTPS traffic. Also configure Certificate.

    Enable if requests from clients to the FortiWeb appliance or back-end servers use SSL or TLS. See also Supported cipher suites & protocol versions.

    When enabled, the FortiWeb appliance handles SSL negotiations and encryption and decryption, instead of the web servers, also known as SSL offloading. For details, see Offloading vs. inspection.

    Connections between the client and the FortiWeb appliance are encrypted. The server pool configuration specifies whether connections between the FortiWeb appliance and each web server are encrypted.

    This option is available only in Reverse Proxy mode. For other operation modes, use the server pool configuration to enable SSL inspection. For details, see Creating a server pool.

    Caution: If you do not enable an HTTPS option and provide a certificate for HTTPS connections, FortiWeb cannot decrypt connections and scan content in the HTTP body.

    Tip: FortiWeb appliances contain specialized hardware to accelerate SSL processing. Offloading SSL/TLS processing can improve the performance of secure HTTP (HTTPS) connections.

    HTTP/2

    Enable FortiWeb to negotiate HTTP/2 with clients via SSL ALPN (Application-Layer Protocol Negotiation) during the SSL handshake if the client's browser supports the HTTP/2 protocol. If HTTP/2 is enabled, FortiWeb will recognize HTTP/2 traffic and apply the security services to it.

    Note: This option is available only if the Deployment Mode is Single Server/Server Pool or HTTP Content Routingand HTTPS Service is configured correctly. This is because FortiWeb supports HTTP/2 only for HTTPS connections. Please keep in mind that if the Deployment Mode is HTTP Content Routing, client requests can use HTTP/2, but traffic between FortiWeb and the server(s) must use HTTP, so the HTTP/2 setting in a server pool configuration would have to remain disabled. For details, see Defining your web servers.

    To configure HTTP/2 in True Transparent Proxy mode, see HTTP/2 support

    Enable Multi-certificate Enable this option to allow FortiWeb to use multiple local certificates.
    Multi-certificate Select the local server certificate created in System > Certificates > Multi-certificate that FortiWeb uses to encrypt or decrypt SSL-secured connections for the website specified by Configuring an HTTP server policy. For details, see Configuring an HTTP server policy.
    Certificate

    Select the server certificate that FortiWeb uses to encrypt or decrypt SSL-secured connections.

    For details, see Uploading a server certificate and Offloading vs. inspection.

    If Enable Server Name Indication (SNI) is selected, FortiWeb uses a Server Name Indication (SNI) configuration instead of or in addition to this server certificate.

    Available only if you specify a value for HTTPS Service.

    Certificate Intermediate Group

    Select the name of a group of intermediate certificate authority (CA) certificates, if any, that FortiWeb presents to clients. An intermediate CA can complete the signing chain and validate the server certificate’s CA signature.

    Configure this option when clients receive certificate warnings that an intermediary CA has signed the server certificate specified by the selected Certificate, not a root CA or other CA currently trusted by the client directly.

    Alternatively, you can include the entire signing chain in the server certificate itself before you upload it to FortiWeb. For details, see Uploading a server certificate and Supplementing a server certificate with its signing chain.

    Available only if you specify a value for HTTPS Service.

    Show/Hide advanced SSL settings

    Click to show or hide the settings that allow you to specify a Server Name Indication (SNI) configuration, increase security by disabling specific versions of TLS and SSL for this policy, and other advanced SSL settings.

    For example, if FortiWeb can use a single certificate to decrypt and encrypt traffic for all the websites that reside on the servers in a pool, you may not have to set any advanced SSL settings.

    Available only if you specify a value for HTTPS Service.

    Add HSTS Header

    Enable to combat MITM attacks on HTTP by injecting the RFC 6797 (http://tools.ietf.org/html/rfc6797) strict transport security header into the reply. For example:

    Strict-Transport-Security: max-age=31536000

    This header forces clients to use HTTPS for subsequent visits to this domain. If the certificate is invalid, the client’s web browser receives a fatal connection error and does not display a dialog that allows the user to override the certificate mismatch error and continue.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Max. Age

    Specify the time to live in seconds for the HSTS header.

    Available only if Add HSTS Header is selected.

    Add HPKP Header

    Select an HPKP profile, if any, to use to verify certificates when clients attempt to access a server.

    HPKP prevents attackers from carrying out Man in the Middle (MITM) attacks with forged certificates. For details, see HTTP Public Key Pinning.

    Available only if you specify a value for HTTPS Service.

    Certificate Verification

    Select the name of a certificate verifier, if any, that FortiWeb uses to validate an HTTP client’s personal certificate.

    Personal certificates, sometimes also called user certificates, establish the identity of the person connecting to the website (PKI authentication). If a User Tracking Policy or Site Publish rule fails to track a user, FortiWeb will attempt to track a user with his or her email address provided in the client certificate via Certificate Verification.

    You can require clients to present a certificate instead of, or in addition to, HTTP authentication. For details, see Offloading HTTP authentication & authorization.

    Available only if you specify a value for HTTPS Service.

    For True Transparent Proxy mode, configure this setting in the server pool configuration instead. For details, see Certificate Verification.

    Note: The client must support TLS 1.0, TLS 1.1, TLS 1.2, and TLS 1.3.

    If you select Enable Server Name Indication (SNI) and the domain in the client request matches an entry in the specified SNI policy, FortiWeb uses the SNI configuration to determine which certificate verifier to use instead.

    If you do not select a verifier, clients are not required to present a personal certificate. For details, see How to apply PKI client authentication (personal certificates).

    Enable URL Based Client Certificate

    Specifies whether FortiWeb uses a URL-based client certificate group to determine whether a client is required to present a personal certificate.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Note: This function is not supported for HTTP/2 communication between the Client and this back-end web server.

    URL Based Client Certificate Group

    Specifies the URL-based client certificate group that determines whether a client is required to present a personal certificate.

    If the URL the client requests does not match an entry in the group, the client is not required to present a personal certificate.

    For information on creating a group, see Use URLs to determine whether a client is required to present a certificate.

    Available only if Enable URL Based Client Certificate is selected.

    Max HTTP Request Length

    Specifies the maximum allowed length for an HTTP request with a URL that matches an entry in the URL-based client certificate group.

    FortiWeb blocks any matching requests that exceed the specified size.

    This setting prevents a request from exceeding the maximum buffer size.

    Available only if Enable URL Based Client Certificate is selected.

    Client Certificate Forwarding

    Enable to configure FortiWeb to include the X.509 personal certificate presented by the client during the SSL/TLS handshake, if any, in an X-Client-Cert: HTTP header when it forwards the traffic to the protected web server.

    FortiWeb still validates the client certificate itself, but this forwarding action can be useful if the web server requires the client certificate for server-side identity-based functionality

    Note: It is necessary to set Certificate Verification to make this option effective.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Custom Header of CCF Subject

    Enter a custom subject header that will be inserted in the X.509 personal certificate presented by the client during the SSL/TLS handshake.

    Available only if Client Certificate Forwarding is selected.

    Customer Header of CCF Certificate

    Enter a custom certificate header that will be inserted in the X.509 personal certificate presented by the client during the SSL/TLS handshake.

    Available only if Client Certificate Forwarding is selected.

    Enable Server Name Indication (SNI)

    Select to use a Server Name Indication (SNI) configuration instead of or in addition to the server certificate specified by the Certificate.

    The SNI configuration enables FortiWeb to determine which certificate to present on behalf of the members of a pool based on the domain in the client request. For details, see Allowing FortiWeb to support multiple server certificates.

    If you specify both an SNI configuration and Certificate, FortiWeb uses the certificate specified by Certificate when the requested domain does not match a value in the SNI configuration.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Enable Strict SNI

    Select so that FortiWeb will ignore the Certificate when it determines which certificate to present on behalf of server pool members, even if the domain in a client request does not match a value in the SNI configuration.

    Available only if Enable Server Name Indication (SNI) is selected.

    SNI Policy

    Select the Server Name Indication (SNI) configuration that determines which certificate FortiWeb presents on behalf of the members of a server pool.

    Available only if Enable Server Name Indication (SNI) is selected.

    SSL Protocols

    Specify which versions of the SSL or TLS cryptographic protocols clients can use to connect securely to the FortiWeb appliance.

    TLS protocol changes a lot since version 1.3, including the handshake algorithm, the supported ciphers and certificates. Make sure you understand how it works before enabling TLS 1.3.

    Note: O-RTT in TLS 1.3 is disabled by default. You can use the following command to enable it:

    config server-policy setting

    set tls13-early-data-mode enable

    end

    For the supported ciphers of each TLS version, see Supported cipher suites & protocol versions.

    This option is available when:

    For details, see Supported cipher suites & protocol versions.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    SSL/TLS encryption level

    Specify whether the set of cipher suites that FortiWeb allows creates a medium-security, high-security or customized security configuration.

    If you select Customized, you can select a cipher and then use the arrow keys to move it to the appropriate list.

    For details, see Supported cipher suites & protocol versions.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Disable Client-Initiated SSL Renegotiation

    Select to configure FortiWeb to ignore requests from clients to renegotiate TLS or SSL.

    Protect against denial-of-service (DoS) attacks that use TLS/SSL renegotiation to overburden the server.

    Available only if you specify a value for HTTPS Service and select Show advanced SSL settings.

    Proxy Protocol

    Enable this option when proxy servers or load balancers are installed before FortiWeb, for example, when a load balancer with proxy protocol enabled is deployed before FortiWeb-VM on AWS.

    When Proxy Protocol is enabled, FortiWeb can receive client connection information in the proxy protocol package passed through proxy servers and load balancers.

    Redirect HTTP to HTTPS

    Select to automatically redirect all HTTP requests to the HTTPS service with the same URL and parameters. If you select this option, ensure to configure HTTPS Service.

    If selected, FortiWeb does not apply the protection profile for this policy specified by the Web Protection Profile to the redirected traffic.

    This option can replace redirection functionality that you create using URL rewriting rules. For details, see Example: HTTP-to-HTTPS redirect.

    This option is available only in Reverse Proxy mode.

    Web Protection Profile

    Select the profile to apply to the connections that this policy accepts, or select Create New to add a new profile in a pop-up window, without leaving the current page.

    For details on specific protection profiles, see one of the following topics:

    Note: The current operation mode determines which profiles are available. For details, see How operation mode affects server policy behavior.

    Note: FortiWeb does not block clients with source IP addresses designated as a trusted IP. For details, see Blacklisting & whitelisting clients using a source IP or source IP range.

    If the Deployment Mode is set to HTTP Content Routing, this option is effective when you create the list of content routing policies.

    Replacement Message

    Select the replacement message to apply to the policy.

    View Profile Details

    Click to display the settings of the current profile without leaving the current page. When viewing a profile, you can also modify its settings from here.

    To return to the policy settings, click Back to Policy Settings.

    Monitor Mode

    Enable to override any actions included in the profiles. Instead, FortiWeb will accept all requests and generate an alert email and/or log message for all policy violations.

    This setting does not affect any rewriting or redirection actions in the protection profiles, including the action to remove poisoned cookies.

    Note: Logging and/or alert email occur only if you enable and configure them. For details, see Logging and Alert email.

    URL Case Sensitivity

    Enable to differentiate uniform resource locators (URLs) according to upper case and lower case letters for features that act upon the URLs in the headers of HTTP requests, such as start page rules, IP list rules, and page access rules.

    For example, when this option is enabled, an HTTP request involving http://www.Example.com/ would not match profile features that specify http://www.example.com (difference is lower case “e”).

    Comments Type a description or other comment. The description can be up to 999 characters long.
  • Click OK.
  • The server policy is displayed in the list on Policy > Server Policy. Initially, it is enabled. For details on disabling a policy without deleting it, see Enabling or disabling a policy.

    Legitimate traffic should now be able to flow, while policy-violating traffic (that is, traffic that is prohibited by the settings in your policy or protection profile) may be blocked, depending on your Action settings for the rule that the traffic has violated.

    Whitelisted items are not included in policy enforcement. For details, see Configuring the global object white list.

  • To verify the policy, test it by forming connections between legitimate clients and servers at various points within your network topology. Also attempt to send traffic that violates your policy, and should be logged, modified, or blocked.
  • If you have another FortiWeb appliance, you can use its web vulnerability scanner to verify that your policy is blocking attacks as you expect. For details, see Vulnerability scans.

    If a connection fails, you can use tools included in the firmware to determine whether the problem is local to the appliance or elsewhere on the network. For details, see Troubleshooting and Reducing false positives. Also consider troubleshooting recommendations included with each feature’s instructions.

    See also

    HTTP pipelining

    For clients that support HTTP 1.1, FortiWeb accelerates transactions by bundling them inside the same TCP connection, instead of waiting for a response before sending/receiving the next request. This can increase performance when pages containing many images, scripts, and other auxiliary files are all hosted on the same domain, and therefore logically could use the same connection.

    Many browsers used on smart phones prefer to pipeline their HTTP requests.

    When FortiWeb is operating in Reverse Proxy or True Transparent Proxy mode, it can automatically use HTTP pipelining for requests with the following characteristics:

    • HTTP version is 1.1
    • The Connection general-header field does not include the "close" option (for example, Connection: close)
    • The HTTP method is GET or HEAD

    Although it is enabled by default, you can use a CLI command to disable or re-enable HTTP pipelining for a specific server policy.

    To disable or enable HTTP pipelining
    1. Connect to the CLI.
    2. In each policy that requires it, enter these commands:

    config server-policy policy

    edit <policy_name>

    set http-pipeline {enable | disable}

    next

    end

     

    For details, see the FortiWeb CLI Reference:

    http://docs.fortinet.com/fortiweb/reference

    See also

    Multiplexing client connections

    By default, FortiWeb establishes a connection with the server for each client that makes a request to the server. When a client makes a request, FortiWeb creates a connection to the server for that client's request. If a second client makes a request, FortiWeb creates another connection to the server for the second client's request.

    You can configure multiplexing so that FortiWeb uses a single connection to a server for requests from multiple clients. If multiplexing is configured, when a client makes a request, FortiWeb establishes a connection to the server for that client's request. Once the request has been completed, FortiWeb caches the connection. If a second client then makes a request to the server, FortiWeb uses the cached connection for the second client's request. You can configure the circumstances in which FortiWeb caches a server connection and reuses it for requests from other clients.

    To configure multiplexing
    1. Connect to the CLI.
    2. In each policy that requires it, enter these commands:

    config server-policy server-pool

    edit <server_pool_name>

    set http-reuse {aggressive | always | never | safe}

    set reuse-conn-idle-time <int>

    set reuse-conn-max-count <int>

    set reuse-conn-max-request <int>

    set reuse-conn-total-time <int>

    next

    end

     

    For details, see the FortiWeb CLI Reference:

    http://docs.fortinet.com/fortiweb/reference

    Enabling or disabling a policy

    You can individually enable and disable policies.

    When the operation mode is Reverse Proxy, disabling a policy could block traffic if no remaining active policies match that traffic. When no policies exist or none are enabled, the FortiWeb appliance blocks all HTTP/HTTPS traffic.

    Even if you disable a server policy, it still consumes memory (RAM). If you do not plan to use the policy for some time, consider deleting it instead.

    To enable or disable a policy
    1. Go to Policy > Server Policy.
    2. In the row corresponding to the policy that you want to enable, click the switch on in the Enable column.
    3. In the row corresponding to the policy that you want to disable, click the switch off in the Enable column.