Huawei Quidway NetEngine80E Configuration Manual page 923

HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
Objectives
To prevent a
device from
modifying the
Next_Hops of
the routes
imported from
an IGP before
advertising the
routes to IBGP
peers.
To prevent a
device from
modifying the
Next_Hops of
routes before
advertising the
routes to
EBGP peers.
To configure
BGP
Next_Hop
iteration based
on a route-
policy.
Issue 02 (2014-09-30)
Command
peer { ipv4-address |
group-name } next-
hop-invariable
peer { group-name |
ipv4-address } next-
hop-invariable
nexthop recursive-
lookup route-policy
route-policy-name
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Copyright © Huawei Technologies Co., Ltd.
Usage Scenarios
-
In an inter-AS VPN Option
C scenario where an RR is
used, the peer next-hop-
invariable command
needs to be run on the RR
to prevent the RR from
modifying the Next_Hops
of routes before
advertising the routes to
EBGP peers. This ensures
that the remote PE iterates
routes to the LSP destined
for the local PE during
traffic transmission.
To enable a device to
iterate only desired routes,
configure Next_Hop
iteration based on a
specified route-policy so
that only the routes that
match the route-policy are
iterated.
8 BGP Configuration
Remarks
By default, a device
modifies the
Next_Hops of the
routes imported from
an IGP to the local IP
address before
advertising the routes
to IBGP peers.
By default, a device
modifies the
Next_Hops of routes
to the local IP
address before
advertising the routes
to EBGP peers.
In addition, a device
does not modify the
Next_Hops of non-
labeled routes if the
routes are learned
from EBGP peers
and are to be
advertised to IBGP
peers; the device sets
its interface IP
address as the
Next_Hops of
labeled routes if the
routes are learned
from EBGP peers
and are to be
advertised to IBGP
peers.
By default,
Next_Hop iteration
based on a specified
route-policy is not
configured.
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