BGP Required Information¶
Before starting, take the time to gather all of the information required to form a BGP adjacency to a neighbor. At a minimum, TNSR will need to know these items:
- VRF Name:
The name of the Virtual Routing and Forwarding instance for which this BGP instance will manage routes, or
default
for the default route table.- Local AS Number:
The autonomous system (AS) number for TNSR. This is typically assigned by an upstream source, an RIR, or mutually agreed upon by internal neighbors.
- Local Router ID:
Typically the highest numbered local address on the firewall. This is also frequently set as the internal or LAN side IP address of a router. It does not matter what this ID is, so long as it is given in IPv4 address notation and does not conflict with any neighbors.
- Local Network(s):
The list of networks that are advertised over BGP as belonging to the Local AS. For external BGP, this is typically the IP address block allocated by the RIR. For internal BGP, this may be a list of local networks or a summarized block.
- Neighbor AS Number:
The autonomous system number of the neighbor.
- Neighbor IP Address:
The IP address of the neighboring router.
The example in this section uses the following values:
Item |
Value |
---|---|
VRF Name |
default |
Local AS Number |
65002 |
Local Router ID |
10.2.0.1 |
Local Network(s) |
10.2.0.0/16 |
Neighbor AS Number |
65005 |
Neighbor IP Address |
203.0.113.14 |
Warning
If NAT is active on the same interface acting as a BGP peer, then NAT forwarding must also be enabled. See NAT Forwarding.