Huawei Quidway NetEngine80E Configuration Manual page 949

HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
The Accumulated Interior Gateway Protocol Metric (AIGP) attribute is an optional non-
transitive Border Gateway Protocol (BGP) path attribute. After the AIGP attribute is configured
in an AIGP administrative domain, BGP selects paths based on costs in the same manner as an
IGP, and all devices in the domain forward data along the optimal routes. During BGP route
selection, the AIGP attribute is used as follows:
l
l
The AIGP attribute can be added to routes only through route-policies. You can configure an
apply clause for a route-policy using the apply aigp { cost | inherit-cost } command to modify
the AIGP value during BGP route import, acceptance, or advertisement. If no AIGP value is
configured, the IGP routes imported by BGP do not carry the AIGP attribute.
In Figure
Router A and Router E and between Router B and Router E. Router A and Router B are
configured to import OSPF routes in AS 65002 and advertise the routes to AS 65001.
Figure 8-18 AIGP application networking
Run the display bgp routing-table [ ip-address ] command on Router E to check the
configurations. The route 10.1.4.0/30 is used in this example.
Issue 02 (2014-09-30)
The priority of a route that carries the AIGP attribute is higher than the priority of a route
that does not carry the AIGP attribute.
If two BGP routes both carry the AIGP attribute, the device selects the BGP route whose
AIGP value plus the cost of the IGP route to which the BGP route is iterated is smaller.
8-18, OSPF runs in AS 65002, an EBGP peer relationship is established between
10.1.1.1/30
EBGP
10.1.1.2/30
Router A
10.1.2.1/30
10.1.2.2/30
Router C
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AS 65001
Router E
10.1.3.1/30
EBGP
AS 65002
10.1.4.1/30
10.1.4.2/30
8 BGP Configuration
10.1.3.2/30
Router B
10.1.5.1/30
10.1.5.2/30
Router D
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