To configure BGP to form neighborship with non-directly-connected external peers, use the neighbor ebgp-multihop command.
This command is relevant only for external BGP neighbors. For internal BGP neighbors, the TTL value remains 64 and can't be modified. A neighbor can inherit this configuration from a peer template. To make the update-source config work for external BGP neighbors, ebgp-multihop hop-count should be configured to increase the TTL value instead of the default TTL of 1.
Issue this command in Peer Template Configuration mode to add it to a peer template.
| Default | 1 |
| Format | neighbor { ip-address | ipv6-address [ interface interface-name ] | autodetect interface interface-name } ebgp-multihop hop-count |
| Mode |
|
| Parameter | Description |
|---|---|
| ip-address | The neighbor's IPv4 address. |
| ipv6-address [interface interface-name] | The neighbor's IPv6 address. If the neighbor's IPv6 address is a link local address, the local interface must also be specified. |
| autodetect interface interface-name | The routing interface on which the neighbor's link local IPv6 address is auto-detected. |
| ebgp-multihop hop- count | The maximum hop-count allowed to reach the neighbor. The allowed range is 1-255. |
Example:
(R1) (Config)# router bgp 65000 (R1) (Config-router)# neighbor 172.20.1.2 remote-as 65001 (R1) (Config-router)# neighbor 172.20.1.2 ebgp-multihop 3 (R1) (Config-router)# neighbor 2001::2 remote-as 65003 (R1) (Config-router)# neighbor 2001::2 ebgp-multihop 4
