DELL 9.7(0.0) ユーザーズマニュアル
Figure 22. Before and After AS Number Migration with Local-AS Enabled
When you complete your migration, and you have reconfigured your network with the new information,
disable this feature.
disable this feature.
If you use the “no prepend” option, the Local-AS does not prepend to the updates received from the
eBGP peer. If you do not select “no prepend” (the default), the Local-AS is added to the first AS segment
in the AS-PATH. If an inbound route-map is used to prepend the as-path to the update from the peer, the
Local-AS is added first. For example, consider the topology described in the previous illustration. If Router
B has an inbound route-map applied on Router C to prepend "65001 65002" to the as-path, the
following events take place on Router B:
eBGP peer. If you do not select “no prepend” (the default), the Local-AS is added to the first AS segment
in the AS-PATH. If an inbound route-map is used to prepend the as-path to the update from the peer, the
Local-AS is added first. For example, consider the topology described in the previous illustration. If Router
B has an inbound route-map applied on Router C to prepend "65001 65002" to the as-path, the
following events take place on Router B:
1.
Receive and validate the update.
2.
Prepend local-as 200 to as-path.
3.
Prepend "65001 65002" to as-path.
Local-AS is prepended before the route-map to give an impression that update passed through a router
in AS 200 before it reached Router B.
in AS 200 before it reached Router B.
Border Gateway Protocol IPv4 (BGPv4)
165