R0106-HP MSR Router Series Layer 3 - IP Routing Command Reference(V7)

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Predefined user roles
network-admin
Parameters
group-name: Specifies a peer group by its name, a case-sensitive string of 1 to 47 characters. The peer
group must have been created.
ip-address: Specifies a peer by its IP address. The peer must have been created.
ipv6-address: Specifies a peer by its IPv6 address. The peer must have been created.
number: Specifies the number of times for which the local AS number can appear, in the range of 1 to
10. The default number is 1. If the number of times for which the local AS number appears in a route is
more than the specified number, BGP considers that a routing loop occurs and discards the route.
Usage guidelines
By default, BGP does not receive routes that contain the local AS number in the AS_PATH attribute to
avoid routing loops. However, in some network environments, the AS_PATH attribute of a route from a
peer must be allowed to contain the local AS number (for example, a Hub&Spoke network in MPLS
L3VPN). Otherwise, the route cannot be advertised correctly.
Examples
# In BGP IPv4 unicast address family view, configure the number of times the local AS number can
appear in AS_PATH attribute of routes from peer group test as 2.
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] address-family ipv4 unicast
[Sysname-bgp-ipv4] peer test allow-as-loop 2
# In BGP VPNv4 address family view, configure the number of times the local AS number can appear in
AS_PATH attribute of routes from peer group test as 2.
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] address-family vpnv4
[Sysname-bgp-vpnv4] peer test allow-as-loop 2
# In BGP-VPN IPv6 unicast address family view, configure the number of times the local AS number can
appear in AS_PATH attribute of routes from peer group test as 2.
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] ip vpn-instance vpn1
[Sysname-bgp-vpn1] address-family ipv6 unicast
[Sysname-bgp-ipv6-vpn1] peer test allow-as-loop 2
# In BGP L2VPN address family view, configure the number of times the local AS number can appear in
AS_PATH attribute of routes from peer group test as 2.
<Sysname> system-view
[Sysname] bgp 100
[Sysname-bgp] address-family l2vpn
[Sysname-bgp-l2vpn] peer test allow-as-loop 2
peer as-number (for a BGP peer)
Use peer as-number to create a BGP peer and specify its AS number.