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:

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:

Example BGP Configuration

Item

Value

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.