Huawei quidway s7700 Configuration Manual page 348

Quidway S7700 Smart Routing Switch
Configuration Guide - VPN
Issue 01 (2011-07-15)
The BGP view is displayed.
3. Run:
ipv6-family vpn6-instance vpn6-instance-name
The BGP-VPN6 instance view is displayed.
4. (Optional) Run:
as-number as-number
An AS number for the IPv6 VPN instance is specified.
During network transfer or service identification, a device needs to be simulated as
multiple BGP devices logically. In this case, you can run the as-number command
to configure an AS number for each IPv6 VPN instance .
NOTE
The AS number configured in the BGP-VPNv6 instance view cannot be the same as the AS
number configured in the BGP view.
5. Run:
peer ipv6-address as-number as-number
The CE is specified as an IPv6 VPN peer.
6. (Optional) Run:
peer { ipv6-address | group-name } ebgp-max-hop [ hop-count ]
The maximum hop of the EBGP peer is configured.
Generally, the EBGP peers have directly connected physical links between each other.
If not, you must use the peer ebgp-max-hop command to permit the EBGP peers to
set up the TCP connection through multiple hops.
7. (Optional) Run:
peer ipv6-address allow-as-loop [ number ]
Routing loop is allowed.
Step 6 applies to the Hub and Spoke networking.
The BGP uses the AS number to detect a routing loop. In the case of Hub and Spoke
networking, however, if EBGP runs between the PE and the CE at the Hub site, the
Hub-PE carries the local AS number when advertising routes to the Hub-CE.
Therefore, the PE denies the subsequent update from the Hub-CE, because it contains
the local AS number. To ensure proper transmission of routes in the Hub and Spoke
scenario, configure all the BGP peers along the path, used for the Hub-CE to advertise
private network routes to the Spoke-CE, to accept the routes which have the AS
number repeated once.
8. (Optional) Run:
peer ipv6-address substitute-as
The function of substituting AS numbers of BGP is enabled.
This step is used for the networking scenario where physically-dispersed CEs use the
same AS number.
Do as follows on the CE:
1. Run:
system-view
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4 BGP MPLS IPv6 VPN Configuration
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