H3C Technologies H3C S12500 Series Switches - Manual (Page 247)

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After you enable the BGP ORF capability, the local BGP router negotiates the ORF capability with the
BGP peer through Open messages (determines whether to carry ORF information in messages, and if yes,
whether to carry non-standard ORF information in the packets). After completing the negotiation process
and establishing the BGP session, the BGP router and its BGP peer can exchange ORF information
through specific route-refresh messages.
For the parameters configured on both sides for ORF capability negotiation, see
Table 8 .
To enable the BGP ORF capability:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter BGP view or BGP-VPN
instance view.
• Enter BGP view:
bgp as-number
• Enter BGP-VPN instance view:
a. bgp as-number
b. ipv4-family vpn-instance
vpn-instance-name
Use either method.
3. Enable BGP route refresh for a
peer or peer group.
peer { group-name | ip-address }
capability-advertise route-refresh
Enabled by default.
4. Enable the non-standard ORF
capability for a BGP peer or
peer group.
peer { group-name | ip-address }
capability-advertise orf
non-standard
Optional.
By default, standard BGP ORF
capability defined in RFC 5291
and RFC 5292 is supported.
If the peer supports only
non-standard ORF, you need to
configure this command.
5. Enable the ORF capability for
a BGP peer or peer group.
peer { group-name | ip-address }
capability-advertise orf ip-prefix
{ both | receive | send }
Disabled by default.
Table 8 Description of the both, send, and receive parameters and the negotiation result
Local parameter Peer parameter Negotiation result
send
• receive
• both
The local end can only send ORF information, and the peer
end can only receive ORF information.
receive
• send
• both
The local end can only receive ORF information, and the
peer end can only send ORF information.
both both
Both the local and peer ends can send and receive ORF
information.
Enabling 4-byte AS number suppression
When a device that supports 4-byte AS numbers sends an Open message for session establishment, the
Optional parameters field of the message indicates that the AS number occupies four bytes—in the
range of 1 to 4294967295. If the peer device does not support 4-byte AS numbers (for examples, it
supports only 2-byte AS numbers), the session cannot be established.