How to establish BGP connection?
Support Model :
Border Gateway Protocol (BGP) is a protocol used for exchanging routing information among the routers (autonomous systems).
BGP uses TCP port 179 to exchange messages with other ASs. When the BGP connection is established, routers will exchange their routing information including the full paths to reach each destinations. When a router is advertised the routing information from its neighbors, it can determine the routes by BGP AS numbers(ASN).
BGP is classified into Internal BGP (IBGP) and External BGP (EBGP) by ASN. BGP connection between routers with the same ASN is IBGP, the other is EBGP. The routing information from EBGP will be exchanged to all neighbors in IBGP and EBGP, while the routing information from IGBP will not be exchanged to its neighbors in IBGP.
This document demonstrates how to set up BGP between a Vigor2860 and a Vigor2862 which is connected on the WAN side. Suppose Vigor2860 and Vigor2862 both have several routing subnets, and we would like the routing information of their routing subnets to be announced to each other.
(This article applies to most of the models. For Vigor3900, Vigor2960 and Vigor300B, please refer to the article here.)
1. Go to BGP Routing >> Basic Settings,
- Check Enable BGP
- Give it a unique Local AS (Autonomous System) Number
- Configure Hold Time for received routes
- Configure Connect Retry Time
2. Click available Index in Neighbor
a. Enable profile
b. Enter Profile Name
c. Enter the AS number of Vigor2860
d. Enter the WAN IP address of Vigor2860
e. Click OK
3. Go to BGP Routing >> Static Network, enter the IP address and Subnet Mask of advertised routes.
4. Go to BGP Routing >> Basic Settings and repeat step 1~3, the configuration should be as follows:
The status will show "Established" after the routing information of the routing subnets to be announced to each other.
We can go to Diagnostics >> Routing Table to verify that the routes to the other router will be through its WAN IP, and the routes type will be "B" which means BGP.
If Network Administrator add or delete static network on BGP Configuration page, the routing table of the BGP Neighbor will change accordingly. For example, if we delete a static network on Vigor2862.
The deleted network will be cleared from the Routing Table of Vigor2860 when hold time is up.