Juniper JUNOSE, Configuration Manual

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Configuring PE-to-PE LSPs
See “Configuring MPLS” on page 263, for information about configuring LSPs.
Enabling BGP Routing
You must enable the BGP routing process on the router serving as the PE router.
router bgp
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Use to enable the BGP routing protocol and to specify the local AS—the AS to
which this BGP speaker belongs.
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All subsequent BGP configuration commands are placed within the context of
this router and AS; you can have only a single BGP instance per virtual router.
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Specify only one BGP AS per virtual router.
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Example
host1:vr1(config)# router bgp 100
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This command takes effect immediately.
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Use the no version to remove the BGP process.
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See router bgp.
Enabling BGP ECMP for BGP/MPLS VPNs
Enabling ECMP support for BGP/MPLS VPNs allows multiple VPN routes to be included
in the list of available equal-cost paths. You can use the
maximum-paths command
with the ibgp or eibgp keywords to enable ECMP support for BGP/MPLS VPNs.
The eibgp keyword specifies that the E Series router consider both external BGP
(EBGP) and internal BGP (IBGP) paths when determining the number of equal-cost
paths to the same destination that BGP can submit to the IP routing table. The
ibgp
keyword specifies that the E Series router consider multiple internal IBGP paths, but
not EBGP paths, when determining the number of equal-cost paths.
Example 1
You can create an ECMP environment in which multiple IBGP paths are selected as
multipaths and used for load balancing. In the example shown in Figure 93 on
page 435, the E Series router gives equal consideration to IBGP VPN routes learned
from multiple remote PE devices when determining load balancing.
434 ■
Configuring BGP VPN Services
JUNOSe 11.0.x BGP and MPLS Configuration Guide