Function
The peer capability-advertise command enables BGP to convey 4-byte AS number, route-refresh, or regular router capability to its peer.
The undo peer capability-advertise command disables BGP from conveying 4-byte AS number, route-refresh, or regular router capability to its peer.
By default, BGP conveys route-refresh capability and 4-byte AS number capability to its neighbors.
Format
peer { group-name | ipv4-address } capability-advertise { 4-byte-as | route-refresh | conventional }
peer ipv6-address capability-advertise { 4-byte-as | route-refresh }
undo peer { group-name | ipv4-address } capability-advertise { 4-byte-as | route-refresh | conventional }
undo peer ipv6-address capability-advertise { 4-byte-as | route-refresh }
Parameters
| Parameter | Description | Value |
|---|---|---|
| group-name | Specifies the name of the peer group. | The name is a string of 1 to 47 characters without any space. It is case-sensitive. |
| ipv4-address | Specifies the IPv4 address of the peer. | - |
| 4-byte-as | Indicates the 4-byte AS number capability. | - |
| route-refresh | Indicates the route-refresh capability. | - |
| conventional | Indicates the regular router function. For IPv6 peers, the parameter is invisible. | - |
| ipv6-address | Specifies the IPv6 address of the peer. | - |
NOTE: ipv4-address is valid only in the BGP view and BGP-VPN instance IPv4 address family view.
ipv6-address is valid only in the BGP view and BGP-VPN instance IPv6 address family view.
Views
BGP view, BGP-VPN instance IPv4 address family view, BGP-VPN instance IPv6 address family view
Usage Guidelines
Usage Scenario
The peer capability-advertise route-refresh command is used to configure a device to advertise the route-refresh capability to its peer.
The peer capability-advertise conventional command is used to configure a device to advertise the regular router capability to its peer. If conventional is specified in the command, the router does not have all extension functions such as route-refresh capability, GR capability, and multi-address family negotiation. This allows the router to be compatible with routers of earlier versions.
The peer capability-advertise 4-byte-as command is used to configure a device to advertise the 4-byte AS number capability to its peer. If AS number resources are used up, this command can be used to configure devices to use 4-byte AS numbers.
Prerequisites
The corresponding BGP session must be in the Established state.
Configuration Impact
Enabling or disabling the regular router capability causes the teardown and re-establishment of sessions.
Precautions
After the peer capability-advertise conventional command is run on a device, the device does not have all extension functions such as route-refresh capability, GR capability, and multi-address family negotiation.