Configuring network interfaces

This section covers the following topics:

• Physical interface
• VLAN interface
• Aggregate interface
• Loopback interface
• Softswitch
• Configuring network interfaces
• Configuring management interface

Physical interfaces

Each physical network port (or vNIC on FortiADC-VM) has a network interface that directly corresponds to it—that is, a “physical network interface.”

Physical ports have three uses:

• Management—The network interface named port1 is typically used as the management interface.
• HA—If you plan to deploy HA, you must reserve a physical port for HA heartbeat and synchronization traffic. Do not configure the network interface that will be used for HA; instead, leave it unconfigured or “reserved” for HA.
• Traffic—The remaining physical ports can be used for your target traffic—these are your “traffic interfaces.”

Traffic interfaces can be associated with logical interfaces. The system supports two types of logical interfaces: VLAN and aggregate. Physical and logical interfaces illustrates how physical ports are associated with physical and logic interfaces.

Physical and logical interfaces

With VLANs, multiple VLAN logical interfaces are associated with a single physical port. With link aggregation, it is the reverse: multiple physical interfaces are associated with a single aggregate logical interface.

Physical network interfaces lists factory default IP addresses for physical network interfaces.

Physical network interfaces

Network Interface*	IPv4 Address/Netmask	IPv6 Address/Netmask
port1	192.168.1.99/24	::/0
port2	0.0.0.0/0	::/0
port3	0.0.0.0/0	::/0
port4	0.0.0.0/0	::/0
...
Connectivity layers that will be considered when distributing frames among the aggregated physical ports: Layer 2 Layer 2-3 Layer 3-4

VLAN interface

You can use IEEE 802.1q VLAN to reduce the size of a broadcast domain, thereby reducing the amount of broadcast traffic received by network hosts and improving network performance.

Unlike physical LANs, VLANs do not require you to install separate hardware switches and routers to achieve this effect. Instead, VLAN-compliant switches restrict broadcast traffic based upon whether its VLAN ID matches that of the destination network. As such, VLAN trunks can be used to join physically distant broadcast domains as if they were close.

The VLAN ID is part of the tag that is inserted into each Ethernet frame in order to identify traffic for a specific VLAN. FortiADC appliances handle VLAN header addition automatically, so you do not need to adjust the maximum transmission unit (MTU). Depending on whether the device receiving a packet operates at Layer 2 or Layer 3 of the network, a VLAN tag might be added, removed, or rewritten before forwarding to other nodes on the network. For example, a Layer 2 switch typically adds or removes a tag when forwarding traffic among members of the VLAN, but does not route tagged traffic to a different VLAN ID. In contrast, a FortiADC content-based routing policy might forward traffic between different VLAN IDs (also known as inter-VLAN routing).

Note: VLANs are not designed to be a security measure, and should not be used where untrusted devices and/or individuals outside of your organization have access to the equipment. VLAN tags are not authenticated, and can be ignored or modified by attackers. VLAN tags rely on the voluntary compliance of the receiving host or switch.

Aggregate interface

Link aggregation (also called NIC teaming/bonding or link bundling) forms a network interface that queues and transmits over multiple wires (also called a port channel), instead of only a single wire (as FortiADC would normally do with a single network interface per physical port). This multiplies the bandwidth that is available to the network interface, and therefore is useful if FortiADC is deployed inline with your network backbone.

Link aggregation on FortiADC complies with IEEE 802.1ax and IEEE 802.3ad and distributes Ethernet frames using a modified round-robin behavior. If a port in the aggregation fails, traffic is redistributed automatically to the remaining ports with the only noticeable effect being a reduced bandwidth. When broadcast or multicast traffic is received on a port in the aggregation, reverse traffic will return on the same port.

When link aggregation uses a round-robin that considers only Layer 2, Ethernet frames that belong to an HTTP request can sometimes arrive out of order. Because network protocols at higher layers often do not gracefully handle this (especially TCP, which may decrease network performance by requesting retransmission when the expected segment does not arrive), FortiADC’s frame distribution algorithm is configurable. For example, if you notice that performance with link aggregation is not as high as you expect, you could try configuring FortiADC to queue related frames consistently to the same port by considering the IP session (Layer 3) and TCP connection (Layer 4), not simply the MAC address (Layer 2).

You must also configure the router, switch, or other link aggregation control protocol (LACP)-compatible device to which FortiADC is connected with the same speed/duplex settings, and it must have ports that can be aggregated. In a deployment like this, the two devices use the cables between the ports to form a trunk, not an accidental Layer 2 (link) network loop. FortiADC uses LACP to detect the following conditions:

• Suitable links between itself and the other device, and form a single logical link.
• Individual port failure so that the aggregate interface can redistribute queuing to avoid a failed port.

Loopback interface

A loopback interface is a virtual interface. Like any other interface, a loopback interface can be assigned an address of its own. Unlike any other interface, a loopback interface, once configured, is always up and available. Because a loopback interface never goes down, it is often used for troubleshooting, i.e., the FortiADC appliance, in our case.

In addition, loopback interfaces are also used by BGP and OSPF protocols to determine properties specific to the protocols for a device or network.

Softswitch

A softswitch, or software switch, is a virtual switch that is implemented at the software or firmware level rather than the hardware level. It can be used to simplify communication between devices connected to different FortiADC interfaces. For example, using a softswitch, you can place the FortiADC interface connected to an internal network on the same subnet as your wireless interfaces. This allows devices on the internal network to communicate with devices on the wireless network without any additional configuration.

A softswitch can also be useful if you require more hardware ports for the switch on a FortiADC unit. For example, if your FortiADC has a 4-port switch, WAN1, WAN2, and DMZ interfaces, and you need one more port, you can create a softswitch that includes the 4-port switch and the DMZ interface all on the same subnet. Such applications also apply to wireless interfaces, virtual wireless interfaces, and physical interfaces.

Similar to a hardware switch, a softswitch functions like a single interface. It has one IP address, and all interfaces in the softswitch are on the same subnet. Traffic between devices connected to each interface is not regulated by security policies, and traffic passing in and out of the switch is affected by the same policy. For more information, see the FortiADC Transparent Mode Configuration Guide.

Configuring network interfaces

You can edit the physical interface configuration. You cannot create or delete a physical interface configuration.

Before you begin:

• You must have Read-Write permission for System settings.

To configure a network interface:

1. Go to Network > Interface.
2. Double-click the row for a physical interface to edit its configuration or click Create New if you want to configure an aggregate or VLAN interface.
3. Complete the configuration as described in Network interface configuration.
4. Save the configuration.

Network interface configuration

Settings	Guidelines
Interface
Name	Configuration name. Valid characters are A-Z, a-z, 0-9, _, and -. No spaces. After you initially save the configuration, you cannot edit the name.
Status	The Status column is not the detected physical link status; it is the administrative status (Up/Down) that indicates whether you permit the network interface to receive and/or transmit packets.
Allow Access	Allow inbound service traffic. Select from the following options: HTTP—Enables connections to the web UI. We recommend this option only for network interfaces connected to a trusted private network, or directly to your management computer. HTTPS—Enables secure connections to the web UI. We recommend this option instead of HTTP. Ping—Enables ping and traceroute to be received on this network interface. When it receives an ECHO_REQUEST (“ping”), FortiADC will reply with ICMP type 0 (ECHO_RESPONSE or “pong”). SNMP—Enables SNMP queries to this network interface. SSH—Enables SSH connections to the CLI. We recommend this option instead of Telnet. Telnet—Enables Telnet connections to the CLI. We recommend this option only for network interfaces connected to a trusted private network, or directly to your management computer.
Dedicated HA management IP	Note: Starting from the v. 4.8.1 release, this option is replaced by "Management Interface". Therefore, it is removed from the GUI though it still remains on the Console. For more information, see Configuring management interface.
Virtual Domain	If applicable, select the virtual domain to which the configuration applies.
Type	Select from the following: VLAN Aggregate Loopback Softswitch Note: If you are editing the configuration for a physical interface, you cannot set the type. If you are configuring a logical interface, you can select from the following options: VLAN—A logical interface you create to VLAN subinterfaces on a single physical interface. Aggregate—A logical interface you create to support the aggregation of multiple physical interfaces.
Mode	Static—Specify a static IP address. The IP address must be on the same subnet as the network to which the interface connects. Two network interfaces cannot have IP addresses on the same subnet (i.e. overlapping subnets). PPPoE—Use PPPoE to retrieve a configuration for the IP address, gateway, and DNS server. For example, if this interface uses a DSL connection to the Internet, your ISP may require this option. DHCP—Use DHCP to automatically assign IP addresses and other communication parameters, including subnet masks, default gateway addresses, and DNS servers to the host.
Traffic Group	Select either of the following: Default Create New Available only if Static is selected for Mode.
Floating	Enable/Disable floating IP. Available only if Static is selected for Mode.
Floating IP	Enter the floating IP. Available only if Floating is enabled.
Type Specifics
VLAN
VLAN ID	VLAN ID of packets that belong to this VLAN. If one physical network port (that is, a VLAN trunk) will handle multiple VLANs, create multiple VLAN subinterfaces on that port, one for each VLAN ID that will be received. If multiple different physical network ports will handle the same VLANs, on each of the ports, create VLAN subinterfaces that have the same VLAN IDs. The valid range is between 1 and 4094. The value you specify must match the VLAN ID added by the IEEE 802.1q-compliant router or switch connected to the VLAN subinterface.
Interface	Physical interface associated with the VLAN; for example, port2.
Aggregate
Member	Select the physical interfaces that are included in the aggregation.
Aggregate Mode	Link aggregation type: 802.3ad Balance-alb Balance-rr Balance-tlb Balance-xor Broadcast
Aggregate Algorithm	Connectivity layers that will be considered when distributing frames among the aggregated physical ports: Layer 2 Layer 2-3 Layer 3-4
Softswitch
Member	Select the interfaces that are included in the softswitch.
Mode Specifics
Static
IPv4/Netmask	Specify the IP address and CIDR-formatted subnet mask, separated by a forward slash ( / ), such as 192.0.2.5/24. Dotted quad formatted subnet masks are not accepted.
IPv6/Netmask	Specify the IP address and CIDR-formatted subnet mask, separated by a forward slash ( / ), such as 2001:0db8:85a3::8a2e:0370:7334/64. Dotted quad formatted subnet masks are not accepted.
WCCP	Enable/disable WCCP to redirect traffic flows in real-time.
Secondary IP Address	Secondary IP addresses can be used when you deploy the system so that it belongs to multiple logical subnets. If you assign multiple IP addresses to an interface, you must assign them static addresses. To add secondary IP addresses, enable the feature and save the configuration. After you have saved it the first time, you can edit it to add secondary IP addresses and enable inbound traffic to that address.
Trust IP Address	Enable/disable the Trust IPs Access Control (TIAC) feature to restrict access to management interfaces according to the Trust IP Address List. If the source IP is not on the Trust IP Address List, the device will refuse the client directly. To add IP addresses to the Trust IP Address List, enable the feature and save the configuration. After you have saved it the first time, you can edit it to add IPs to the list.
PPPoE
WCCP	Enable/disable WCCP to redirect traffic flows in real-time.
Trust IP Address	Enable/disable the Trust IPs Access Control (TIAC) feature to restrict access to management interfaces according to the Trust IP Address List. If the source IP is not on the Trust IP Address List, the device will refuse the client directly. To add IP addresses to the Trust IP Address List, enable the feature and save the configuration. After you have saved it the first time, you can edit it to add IPs to the list.
Username	PPPoE account user name.
Password	PPPoE account password.
Discovery Retry Timeout	Seconds the system waits before it retries to discover the PPPoE server. The default is 5 seconds. The valid range is 1-255.
DNS Server Override	Use the DNS addresses retrieved from the PPPoE server instead of the one configured in the FortiADC system settings.
Retrieve Default Gateway	Use the default gateway retrieved from the PPPoE server instead of the one configured in the FortiADC system settings.
DHCP
WCCP	Enable/disable WCCP to redirect traffic flows in real-time.
Trust IP Address	Enable/disable the Trust IPs Access Control (TIAC) feature to restrict access to management interfaces according to the Trust IP Address List. If the source IP is not on the Trust IP Address List, the device will refuse the client directly. To add IP addresses to the Trust IP Address List, enable the feature and save the configuration. After you have saved it the first time, you can edit it to add IPs to the list.
Retrieve Gateway	Use the default gateway retrieved from the DHCP server instead of the one configured in the FortiADC system settings.
Secondary IP List
IP Address	Secondary IP addresses can be used when you deploy the system so that it belongs to multiple logical subnets. If you assign multiple IP addresses to an interface, you must assign them static addresses. To add secondary IP addresses, enable the feature and save the configuration. After you have saved it the first time, you can edit it to add secondary IP addresses and enable inbound traffic to that address. For each address, specify an IP address using the CIDR-formatted subnet mask, separated by a forward slash ( / ), such as 192.0.2.5/24.
Allow Access	Select the services that are allowed to send inbound traffic.
Trust IP Address List
Name	Configuration name. Valid characters are A-Z, a-z, 0-9, _, and -. No spaces. After you initially save the configuration, you cannot edit the name.
Type	Select the IP address type: IPv4/Netmask IPv4 Address Range IPv6/Netmask IPv6 Address Range
IPv4/Netmask, IPv6/Netmask	Specify the IP address that can access the interface.
Address Range	Specify a range of IP addresses that can access the interface.
HA Node IP List
IP Address	You use the HA node IP list configuration in an HA active-active deployment. On each HA cluster node, add an HA node IP list that includes an entry for each cluster node. When the appliance is in standalone mode, it uses the physical port IP address; when it is in HA mode, it uses the HA node IP list address. For each address, specify an IP address using the CIDR-formatted subnet mask, separated by a forward slash ( / ), such as 192.0.2.5/24.
Node ID	ID of the corresponding node.
Allow Access	Select the services that are allowed to send inbound traffic.

In an HA active-active deployment, if an interface uses secondary IP addresses, you must use the CLI to enable the HA node secondary IP address list, and then configure the list: FADC # config system interface FADC (interface) # edit port3 FADC (port3) # set ha-node-secondary-ip enable FADC (port3) # config ha-node-secondary-ip-list FADC (ha-node-second~r) # edit 1 Add new entry '1' for node 2221 FADC (1) # set ip 192.168.1.100 FADC (1) # set allowaccess https http ping snmp ssh FADC (1) # end FADC (port3) # end

To configure a physical interface in the CLI:

config system interface

edit <port_name>

set ip <ip&netmask>

set allowaccess {http https ping snmp ssh telnet}

end

To configure an aggregate interface in the CLI:

config system interface

edit <specified_name>

set type agg

set aggregate-mode {802.3ad | balance-alb | balance-rr | balance-tlb | balance-xor | broadcast}

set aggregate-algorithm {layer2 | layer2_3 | layer3_4}

set member <port_name> <port_name>

set ip <ip&netmask>

end

To configure a VLAN interface in the CLI:

config system interface

edit <specified_name>

set type vlan

set vlanid <number>

set interface <port_name>

set ip <ip&netmask>

end

To enable/disable the Trust IP Address status in the CLI:

config system interface

edit <port_name>

set trust-ip <enable | disable>

To configure the Trust IP Address List in the CLI:

config trust-ip-list

edit <name>

set type {ip-netmask | ip-range}

set ip-network <ip&netmask>

set start-ip <ip>

set end-ip <ip>

next

edit <name>

set type {ip6-netmask | ip6-range}

set ip6-network <ip6&netmask>

set start-ip6 <ip6>

set end-ip6 <ip6>

next

end