Huawei Quidway NetEngine80E Configuration Manual page 873

HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
<RouterC> display bgp routing-table
BGP Local router ID is 10.1.2.2
Status codes: * - valid, > - best, d - damped,
Total Number of Routes: 3
*>
After the maximum load-balancing number command is run on Router B, Router B changes
the next hop addresses of the routes received from Router A and Router D to 10.1.2.1 used by
Router B to establish an IBGP peer relationship with Router C. Then Router B advertises the
routes to Router C. The command output on Router C is used as an example.
<RouterC> display bgp routing-table
BGP Local router ID is 10.1.2.2
Status codes: * - valid, > - best, d - damped,
Total Number of Routes: 3
*>i
*>i
*>
The next hop address change may lead to the change of the link along which data packets are
forwarded. In
Router D before Router B sends them to Router C, configure import and export routing policies
on Router B.
First, configure an import routing policy on Router B to apply a community attribute to routes
received from Router D. Second, configure an export routing policy with the community attribute
set in the import routing policy as the filtering condition on Router B. If a route matches the
filtering condition, Router B changes the next hop address of the route back to the IP address
used by Router D to establish an EBGP peer relationship with Router B. Then, Router B
advertises the route to Router C. Detailed configurations are as follows:
bgp 200
ipv4-family unicast
peer 10.1.2.2 route-policy out export
peer 10.1.3.2 route-policy in import
#
route-policy in permit node 10
if-match ip next-hop ip-prefix prefix1
apply community 1:1
#
route-policy in permit node 20
#
route-policy out permit node 10
if-match community-filter filter1
apply ip-address next-hop 10.1.3.2
#
route-policy out permit node 20
#
Issue 02 (2014-09-30)
h - history,
Origin : i - IGP, e - EGP, ? - incomplete
Network
i 1.1.1.9/32
i 4.4.4.9/32
10.1.2.0/30
h - history,
Origin : i - IGP, e - EGP, ? - incomplete
Network
1.1.1.9/32
4.4.4.9/32
10.1.2.0/30
Figure 8-4, if you want to keep the next hop addresses of the routes received from
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i - internal, s - suppressed, S - Stale
NextHop MED
10.1.1.1 0
10.1.3.2 0
0.0.0.0 0
i - internal, s - suppressed, S - Stale
NextHop MED
10.1.2.1 0
10.1.2.1 0
0.0.0.0 0
8 BGP Configuration
LocPrf PrefVal Path/Ogn
100 0 100i
100 0 300i
0 i
LocPrf PrefVal Path/Ogn
100 0 100i
100 0 300i
0 i
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