Fortinet Document Library

Version:

Version:


Table of Contents

Cookbook

Download PDF
Copy Link

Configuring RADIUS SSO authentication

A common RADIUS SSO (RSSO) topology involves a medium-sized company network of users connecting to the Internet through the FortiGate and authenticating with a RADIUS server. The following describes how to configure FortiOS for this scenario. The example makes the following assumptions:

  • VDOMs are not enabled.
  • The super_admin account is used for all FortiGate configuration.
  • A RADIUS server is installed on a server or FortiAuthenticator and uses default attributes.
  • BGP is used for any dynamic routing.
  • You have configured authentication event logging under Log & Report.

Example.com has an office with 20 users on the internal network who need access to the Internet. The office network is protected by a FortiGate-60C with access to the Internet through the wan1 interface, the user network on the internal interface, and all servers are on the DMZ interface. This includes an Ubuntu sever running FreeRADIUS. This example configures two users:

User

Account

Pat Lee

plee@example.com

Kelly Green

kgreen@example.com

Configuring this example consists of the following steps:

  1. Configure RADIUS.
  2. Configure FortiGate interfaces.
  3. Configure a RSSO agent.
  4. Create a RSSO user group.
  5. Configure security policies.
  6. Test the configuration.
To configure RADIUS:

Configuring RADIUS includes configuring a RADIUS server such as FreeRADIUS on user's computers and configuring users in the system. In this example, Pat and Kelly belong to the exampledotcom_employees group. After completing the configuration, you must start the RADIUS daemon. The users have a RADIUS client installed on their PCs that allow them to authenticate through the RADIUS server.

For any problems installing FreeRADIUS, see the FreeRADIUS documentation.

To configure FortiGate interfaces:

You must define a DHCP server for the internal network, as this network type typically uses DHCP. The wan1 and dmz interfaces are assigned static IP addresses and do not need a DHCP server. The following table shows the FortiGate interfaces used in this example:

Interface Subnet Act as DHCP server Devices
wan1 172.20.120.141 No Internet service provider
dmz 10.11.101.100 No Servers including RADIUS server
internal 10.11.102.100 Yes: x.x.x.110-250 Internal user network
  1. Go to Network > Interfaces.
  2. Edit wan1:

    Alias

    Internet

    Addressing Mode

    Manual

    IP/Network Mask

    172.20.120.141/255.255.255.0

    Administrative Access

    HTTPS, SSH

    Enable DHCP Server

    Not selected

    Comments

    Internet

    Administrative Status

    Up

  3. Click OK.
  4. Edit dmz:

    Alias

    Servers

    Addressing Mode

    Manual

    IP/Network Mask

    10.11.101.100/255.255.255.0

    Administrative Access

    HTTPS, SSH, PING, SNMP

    Enable DHCP Server

    Not selected

    Listen for RADIUS Accounting Messages

    Select

    Comments

    Servers

    Administrative Status

    Up

  5. Click OK.
  6. Edit internal:

    Alias

    Internal network

    Addressing Mode

    Manual

    IP/Network Mask

    10.11.102.100/255.255.255.0

    Administrative Access

    HTTPS, SSH, PING

    Enable DHCP Server

    Select

    Address Range

    10.11.102.110 - 10.11.102.250

    Netmask

    255.255.255.0

    Default Gateway

    Same as Interface IP

    Comments

    Internal network

    Administrative Status

    Up

To create a RADIUS SSO agent:
  1. Go to Security Fabric > Fabric Connectors. Click Create New.
  2. Under SSO/Identity, select RADIUS Single Sign-On Agent.
  3. Enable Use RADIUS Shared Secret. Enter the RADIUS server's shared secret.
  4. Enable Send RADIUS Responses. Click OK.
To create a RADIUS SSO user group:
  1. Go to User & Device > User Groups. Click Create New.
  2. For Type, select RADIUS Single Sign-On (RSSO).
  3. In RADIUS Attribute Value, enter the name of the RADIUS user group that this local user group represents.
  4. Click OK.

Configuring security policies

The following security policies are required for RADIUS SSO:

Sequence Number

From

To

Type

Schedule

Description

1

internal

wan1

RADIUS SSO

Business hours

Authenticate outgoing user traffic

2

internal

wan1

Regular

Always

Allow essential network services and VoIP

3

dmz

wan1

Regular

Always

Allow servers to access the Internet

4

internal

dmz

Regular

Always

Allow users to access servers

5

any

any

Deny

Always

Implicit policy denying all traffic that has not been matched

You must place the RADIUS SSO policy at the top of the policy list so that it is matched first. The only exception to this is if you have a policy to deny access to a list of banned users. In this case, you must put that policy at the top so that the RADIUS SSO does not mistakenly match a banned user or IP address.

You must configure lists before creating security policies.

Schedule

You must configure a business_hours schedule. You can configure a standard Monday to Friday 8 AM to 5 PM schedule, or whatever days and hours covers standard work hours at the company.

Address groups

You must configure the following address groups:

Name

Interface

Address range included

internal_network

internal

10.11.102.110 to 10.11.102.250

company_servers

dmz

10.11.101.110 to 10.11.101.250

Service groups

You must configure the service groups. The services listed are suggestions and you may include more or less as required:

Name

Interface

Description of services to be included

essential_network_services

internal

Any network protocols required for normal network operation such as DNS, NTP, BGP

essential_server_services

dmz

All the protocols required by the company servers such as BGP, HTTP, HTTPS, FTP, IMAP, POP3, SMTP, IKE, SQL, MYSQL, NTP, TRACEROUTE, SOCKs, and SNMP

user_services

internal

Any protocols required by users such as HTTP, HTTPS, FTP

The following security policy configurations are basic and only include logging and default AV and IPS. These policies allow or deny access to non-RADIUS SSO traffic. These are essential as network services including DNS, NTP, and FortiGuard require access to the Internet.

To configure security policies:
  1. Go to Policy & Objects > IPv4 Policy. Click Create New.
  2. Configure the policy as follows, then click OK:

    Incoming Interface

    Internal

    Source Address

    internal_network

    Outgoing Interface

    wan1

    Destination Address

    all

    Schedule

    always

    Service

    essential_network_services

    Action

    ACCEPT

    NAT

    ON

    Security Profiles

    ON: AntiVirus, IPS

    Log Allowed Traffic

    ON

    Comments

    Essential network services

  3. Click Create New, and configure the new policy as follows, then click OK:

    Incoming Interface

    dmz

    Source Address

    company_servers

    Outgoing Interface

    wan1

    Destination Address

    all

    Schedule

    always

    Service

    essential_server_services

    Action

    ACCEPT

    NAT

    ON

    Security Profiles

    ON: AntiVirus, IPS

    Log Allowed Traffic

    enable

    Comments

    Company servers accessing the Internet

  4. Click Create New, and configure the new policy as follows, then click OK:

    Incoming Interface

    Internal

    Source Address

    internal_network

    Outgoing Interface

    dmz

    Destination Address

    company_servers

    Schedule

    always

    Service

    all

    Action

    ACCEPT

    NAT

    ON

    Security Profiles

    ON: AntiVirus, IPS

    Log Allowed Traffic

    enable

    Comments

    Access company servers

  5. Click Create New, and configure the RADIUS SSO policy as follows, then click OK. This policy allows access for members of specific RADIUS groups.

    Incoming Interface

    Internal

    Source Address

    internal_network

    Source User(s)

    Select the user groups that you created for RSSO.

    Outgoing Interface

    wan1

    Destination Address

    all

    Schedule

    business_hours

    Service

    ALL

    Action

    ACCEPT

    NAT

    ON

    Security Profiles

    ON: AntiVirus, Web Filter, IPS, and Email Filter. In each case, select the default profile.

  6. Place the RSSO policy higher in the security policy list than more general policies for the same interfaces. Click OK.
To test the configuration:

Once configured, a user only needs to log in to their PC using their RADIUS account. After that, when they attempt to access the Internet, the FortiGate uses their session information to get their RADIUS information. Once the user is verified, they can access the website.

  1. The user logs on to their PC and tries to access the Internet.
  2. The FortiGate contacts the RADIUS server for the user's information. Once confirmed, the user can access the Internet. Each step generates logs that enable you to verify that each step succeeded.
  3. If a step does not succeed, confirm that your configuration is correct.

Configuring RADIUS SSO authentication

A common RADIUS SSO (RSSO) topology involves a medium-sized company network of users connecting to the Internet through the FortiGate and authenticating with a RADIUS server. The following describes how to configure FortiOS for this scenario. The example makes the following assumptions:

  • VDOMs are not enabled.
  • The super_admin account is used for all FortiGate configuration.
  • A RADIUS server is installed on a server or FortiAuthenticator and uses default attributes.
  • BGP is used for any dynamic routing.
  • You have configured authentication event logging under Log & Report.

Example.com has an office with 20 users on the internal network who need access to the Internet. The office network is protected by a FortiGate-60C with access to the Internet through the wan1 interface, the user network on the internal interface, and all servers are on the DMZ interface. This includes an Ubuntu sever running FreeRADIUS. This example configures two users:

User

Account

Pat Lee

plee@example.com

Kelly Green

kgreen@example.com

Configuring this example consists of the following steps:

  1. Configure RADIUS.
  2. Configure FortiGate interfaces.
  3. Configure a RSSO agent.
  4. Create a RSSO user group.
  5. Configure security policies.
  6. Test the configuration.
To configure RADIUS:

Configuring RADIUS includes configuring a RADIUS server such as FreeRADIUS on user's computers and configuring users in the system. In this example, Pat and Kelly belong to the exampledotcom_employees group. After completing the configuration, you must start the RADIUS daemon. The users have a RADIUS client installed on their PCs that allow them to authenticate through the RADIUS server.

For any problems installing FreeRADIUS, see the FreeRADIUS documentation.

To configure FortiGate interfaces:

You must define a DHCP server for the internal network, as this network type typically uses DHCP. The wan1 and dmz interfaces are assigned static IP addresses and do not need a DHCP server. The following table shows the FortiGate interfaces used in this example:

Interface Subnet Act as DHCP server Devices
wan1 172.20.120.141 No Internet service provider
dmz 10.11.101.100 No Servers including RADIUS server
internal 10.11.102.100 Yes: x.x.x.110-250 Internal user network
  1. Go to Network > Interfaces.
  2. Edit wan1:

    Alias

    Internet

    Addressing Mode

    Manual

    IP/Network Mask

    172.20.120.141/255.255.255.0

    Administrative Access

    HTTPS, SSH

    Enable DHCP Server

    Not selected

    Comments

    Internet

    Administrative Status

    Up

  3. Click OK.
  4. Edit dmz:

    Alias

    Servers

    Addressing Mode

    Manual

    IP/Network Mask

    10.11.101.100/255.255.255.0

    Administrative Access

    HTTPS, SSH, PING, SNMP

    Enable DHCP Server

    Not selected

    Listen for RADIUS Accounting Messages

    Select

    Comments

    Servers

    Administrative Status

    Up

  5. Click OK.
  6. Edit internal:

    Alias

    Internal network

    Addressing Mode

    Manual

    IP/Network Mask

    10.11.102.100/255.255.255.0

    Administrative Access

    HTTPS, SSH, PING

    Enable DHCP Server

    Select

    Address Range

    10.11.102.110 - 10.11.102.250

    Netmask

    255.255.255.0

    Default Gateway

    Same as Interface IP

    Comments

    Internal network

    Administrative Status

    Up

To create a RADIUS SSO agent:
  1. Go to Security Fabric > Fabric Connectors. Click Create New.
  2. Under SSO/Identity, select RADIUS Single Sign-On Agent.
  3. Enable Use RADIUS Shared Secret. Enter the RADIUS server's shared secret.
  4. Enable Send RADIUS Responses. Click OK.
To create a RADIUS SSO user group:
  1. Go to User & Device > User Groups. Click Create New.
  2. For Type, select RADIUS Single Sign-On (RSSO).
  3. In RADIUS Attribute Value, enter the name of the RADIUS user group that this local user group represents.
  4. Click OK.

Configuring security policies

The following security policies are required for RADIUS SSO:

Sequence Number

From

To

Type

Schedule

Description

1

internal

wan1

RADIUS SSO

Business hours

Authenticate outgoing user traffic

2

internal

wan1

Regular

Always

Allow essential network services and VoIP

3

dmz

wan1

Regular

Always

Allow servers to access the Internet

4

internal

dmz

Regular

Always

Allow users to access servers

5

any

any

Deny

Always

Implicit policy denying all traffic that has not been matched

You must place the RADIUS SSO policy at the top of the policy list so that it is matched first. The only exception to this is if you have a policy to deny access to a list of banned users. In this case, you must put that policy at the top so that the RADIUS SSO does not mistakenly match a banned user or IP address.

You must configure lists before creating security policies.

Schedule

You must configure a business_hours schedule. You can configure a standard Monday to Friday 8 AM to 5 PM schedule, or whatever days and hours covers standard work hours at the company.

Address groups

You must configure the following address groups:

Name

Interface

Address range included

internal_network

internal

10.11.102.110 to 10.11.102.250

company_servers

dmz

10.11.101.110 to 10.11.101.250

Service groups

You must configure the service groups. The services listed are suggestions and you may include more or less as required:

Name

Interface

Description of services to be included

essential_network_services

internal

Any network protocols required for normal network operation such as DNS, NTP, BGP

essential_server_services

dmz

All the protocols required by the company servers such as BGP, HTTP, HTTPS, FTP, IMAP, POP3, SMTP, IKE, SQL, MYSQL, NTP, TRACEROUTE, SOCKs, and SNMP

user_services

internal

Any protocols required by users such as HTTP, HTTPS, FTP

The following security policy configurations are basic and only include logging and default AV and IPS. These policies allow or deny access to non-RADIUS SSO traffic. These are essential as network services including DNS, NTP, and FortiGuard require access to the Internet.

To configure security policies:
  1. Go to Policy & Objects > IPv4 Policy. Click Create New.
  2. Configure the policy as follows, then click OK:

    Incoming Interface

    Internal

    Source Address

    internal_network

    Outgoing Interface

    wan1

    Destination Address

    all

    Schedule

    always

    Service

    essential_network_services

    Action

    ACCEPT

    NAT

    ON

    Security Profiles

    ON: AntiVirus, IPS

    Log Allowed Traffic

    ON

    Comments

    Essential network services

  3. Click Create New, and configure the new policy as follows, then click OK:

    Incoming Interface

    dmz

    Source Address

    company_servers

    Outgoing Interface

    wan1

    Destination Address

    all

    Schedule

    always

    Service

    essential_server_services

    Action

    ACCEPT

    NAT

    ON

    Security Profiles

    ON: AntiVirus, IPS

    Log Allowed Traffic

    enable

    Comments

    Company servers accessing the Internet

  4. Click Create New, and configure the new policy as follows, then click OK:

    Incoming Interface

    Internal

    Source Address

    internal_network

    Outgoing Interface

    dmz

    Destination Address

    company_servers

    Schedule

    always

    Service

    all

    Action

    ACCEPT

    NAT

    ON

    Security Profiles

    ON: AntiVirus, IPS

    Log Allowed Traffic

    enable

    Comments

    Access company servers

  5. Click Create New, and configure the RADIUS SSO policy as follows, then click OK. This policy allows access for members of specific RADIUS groups.

    Incoming Interface

    Internal

    Source Address

    internal_network

    Source User(s)

    Select the user groups that you created for RSSO.

    Outgoing Interface

    wan1

    Destination Address

    all

    Schedule

    business_hours

    Service

    ALL

    Action

    ACCEPT

    NAT

    ON

    Security Profiles

    ON: AntiVirus, Web Filter, IPS, and Email Filter. In each case, select the default profile.

  6. Place the RSSO policy higher in the security policy list than more general policies for the same interfaces. Click OK.
To test the configuration:

Once configured, a user only needs to log in to their PC using their RADIUS account. After that, when they attempt to access the Internet, the FortiGate uses their session information to get their RADIUS information. Once the user is verified, they can access the website.

  1. The user logs on to their PC and tries to access the Internet.
  2. The FortiGate contacts the RADIUS server for the user's information. Once confirmed, the user can access the Internet. Each step generates logs that enable you to verify that each step succeeded.
  3. If a step does not succeed, confirm that your configuration is correct.