Juniper JUNOSE 11.2.X BGP AND MPLS, Configuration Manual

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You can configure load balancing in two different ways. You can configure many shim
interfaces with the same peer, VC type, and VC ID. Alternatively, you can use the legacy
method of configuring Martini circuits into load-balancing groups.
Configuration of Many Shim Interfaces with the Same Peer, VC Type, and VC ID
The mpls-relay command enables you to specify the peer and the VC ID explicitly. The
VC type is either automatically determined by the layer 2 interface type or you explicitly
configure the VC type with the
relay-format keyword in the mpls-relay command.
Example: Configuring Many Shim Interfaces with the Same Peer, VC Type, and VC ID
In this example, the following commands create a single layer 2 circuit to the remote
peer 10.9.1.3. Load balancing is established on two shim interfaces, fastEthernet 2/0.1
and fastEthernet 3/0.1. The VC type is determined by the layer 2 interface type.
host1(config)# interface fast 2/0.1
host1(config-subif)# vlan id 1
host1(config-subif)# mpls-relay 10.9.1.3 200001
host1(config-subif)# exit
host1(config)# interface fast 3/0.1
host1(config-subif)# vlan id 1
host1(config-subif)# mpls-relay 10.9.1.3 200001
In this example, the router advertises a single label, 53, to the remote peer, 10.9.1.3, and
receives a single label, 55, from the peer, resulting in the following forwarding table:
host1:# show mpls forwarding brief
Platform label space
In Label Owner Action
-------- -------- -------------------------------------------------------
53 ldp l2transport to FastEthernet3/0.1
l2transport to FastEthernet2/0.1
L2transport
Interface Owner Action
-------------------- -------- -------------------------------------------------
FastEthernet2/0.1 ldp swap to 55, push 42 on ATM5/0.1, nbr 10.10.11.5
FastEthernet3/0.1 ldp swap to 55, push 42 on ATM5/0.1, nbr 10.10.11.5
Traffic that arrives on either interface, 2/0.1 or 3/0.1, is forwarded to the remote peer with
the same label stack (55, 42). Traffic from the remote peer with label 53 is forwarded
to one of the two shim interfaces; the ECMP algorithm determines which of the two shim
interfaces receives the traffic.
In the case of a local cross-connects configuration, the following commands illustrate
how a three-way cross-connect is created when 10.9.1.2 is a local address:
host1(config)# interface atm 6/0.101 point-to-point
host1(config-subif)# mpls-relay 10.9.1.2 600001
host1(config-subif)# exit
host1(config)# interface atm 6/2.101 point-to-point
host1(config-subif)# mpls-relay 10.9.1.2 600001
host1(config-subif)# exit
host1(config)# interface atm 6/2.103 point-to-point
host1(config-subif)# mpls-relay 10.9.1.2 600001
This configuration results in the following forwarding table:
Copyright © 2010, Juniper Networks, Inc. 540
JunosE 11.2.x BGP and MPLS Configuration Guide