Huawei Quidway NetEngine80E Configuration Manual page 955

HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
In Figure
After receiving this route, Router D checks its AS_Path. This AS_Path carries AS 65001, which
is the same as the AS of Router D. As a result, Router D discards this route.
To address this problem, run the peer public-as-only command on Router B so that Router B
deletes AS 65001 before adding AS 100 (public AS) to the AS_Path and forwarding the route
to Router C.
In the following situations, after the peer public-as-only command is configured, BGP does not
delete any private AS number from the AS_Path:
l The AS_Path of a route carries the AS number of the remote peer. In this case, deleting
private AS numbers may lead to a routing loop.
l The AS_Path carries both public and private AS numbers, which indicates that the route
has passed through the public network. In this case, deleting private AS numbers may lead
to incorrect traffic forwarding.
The preceding limitations also apply to confederation scenarios.
Adding AS Numbers
In Figure
paths.
Figure 8-20 Networking in which new AS numbers are added to the AS_Path
Issue 02 (2014-09-30)
8-19, Router A advertises the route 10.0.0.0/8 to Router D through ISP1 and ISP2.
8-20, AS 65005 imports three routes and advertises them to AS 65001 through two
10.1.1.2/30
10.1.1.1/30
AS 65001
10.1.3.1/30
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AS 65002
10.1.2.1/30
Router B
Router A
10.1.3.2/30
AS 65003
8 BGP Configuration
AS 65004
10.1.2.2/30
Router D
Router C
10.1.5.1/30
10.1.4.1/3
10.1
Router E
10.1.5.2
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