Configuring BGP

Configuring BGP on the FortiSwitch unit includes the following major steps:

1. Enter the BGP configuration mode.
2. Set the autonomous system and router identifier.
3. Configure the BGP neighbors.
4. Redistribute non-BGP routes.

   Advertise these non-BGP routes within BGP.

Enter the BGP configuration mode

Enter the BGP configuration mode to access all of the BGP configuration commands:

# config router bgp

Set the autonomous system and router identifier

Set the autonomous system. For iBGP, the AS value needs to match the remote-as value in the neighbor router. For eBGP, the AS value differs from the remote-as value in the neighbor router. You also need to specify a fixed router identifier for the FortiSwitch unit. These two commands are mandatory.

# set as <AS number>

# set router-id <IP_address>

Configure the BGP neighbors

Configure the BGP neighbors.

NOTE: For iBGP, if the IP address of the BGP neighbor is a loopback address, you must use the set update-source cmd command to specify which interface address will be used as the source IP address in the outgoing BGP packet.

config neighbor

edit "<IPv4_or_IPv6 address>"

set remote-as <1-4294967295>

end

Redistribute non-BGP routes

Redistribute non-BGP IPv4 or IPv6 routes within BGP:

config redistribute {connected | isis | ospf | rip | static}

set status enable

set route-map <string>

end

config redistribute6 {connected | isis | ospf | rip | static}

set status {disable | enable}

set route-map <string>

end

Other BGP commands

Clearing the BGP routes

Use the following commands to clear the BGP routes:

execute router clear bgp all

execute router clear bgp ip <IPv4_or_IPv6_address>

execute router clear bgp ipv6 <IPv4_or_IPv6_address>

execute router clear bgp as <AS_number>

execute router clear bgp dampening <IP_address>

Checking the BGP configuration

The get router info bgp and get router info6 bgp commands have options to display different aspects of the BGP configuration and status.

For example:

get router info bgp neighbors

get router info bgp network

get router info6 bgp filter-list

get router info6 bgp route-map

Changing the maximum number of paths for ECMP

If you are using equal-cost multi-path (ECMP) routing with the eBGP or iBGP, the maximum number of paths is 1 by default. Use the following commands to change the default:

config router bgp

set maximum-paths-ebgp <1-64>

set maximum-paths-ibgp <1-64>

end