Enabling 4-Byte As Number Suppression - HP FlexFabric 12900E Series Configuration Manual

Step
2. Enter BGP instance view.
3. Enable
re-establishment
EBGP connections upon link
failure.

Enabling 4-byte AS number suppression

BGP supports 4-byte AS numbers. The 4-byte AS number occupies four bytes, in the range of 1 to
4294967295. By default, a device sends an Open message to the peer device for session
establishment. The Open message indicates that the device supports 4-byte AS numbers. If the peer
device supports 2-byte AS numbers instead of 4-byte AS numbers, the session cannot be
established. To resolve this issue, enable the 4-byte AS number suppression feature. The device
then sends an Open message to inform the peer that it does not support 4-byte AS numbers, so the
BGP session can be established.
If the peer device supports 4-byte AS numbers, do not enable the 4-byte AS number suppression
feature. Otherwise, the BGP session cannot be established.
To enable 4-byte AS number suppression (IPv4 unicast/multicast address family):
Step
1. Enter system view.
2. Enter BGP instance view or
BGP-VPN instance view.
3. Enable 4-byte AS number
suppression.
To enable 4-byte AS number suppression (IPv6 unicast address family):
Step
1. Enter system view.
Command
bgp
as-number
instance-name
[ multi-session-thread ]
immediate
of direct
ebgp-interface-sensitive
Command
system-view
•
Enter BGP instance view:
bgp as-number [ instance
instance-name
[ multi-session-thread ]
•
Enter BGP-VPN
view:
a. bgp
[
instance-name
[ multi-session-thread ]
b. ip
vpn-instance-name
peer { group-name | ipv4-address
[ mask-length
capability-advertise
suppress-4-byte-as
Command
system-view
262
Remarks
instance
[
] N/A
By
re-establishment of direct EBGP
connections is enabled.
Remarks
N/A
]
instance
N/A
as-number
instance
]
vpn-instance
] } By default, 4-byte AS number
suppression is disabled.
Remarks
N/A
default, immediate