MPLS Configuration Example

The network configuration, shown in MPLS Configuration Example, illustrates how to configure a BlackDiamond switch to support a routed MPLS network.

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MPLS Configuration Example

The four switches, labeled LSR 1, LSR 2, LSR 3, and LSR 4, have the same physical hardware configuration. Each switch contains two 8900-G48T-xl and an 8900-MSM128 module. The switches are all interconnected via Gigabit Ethernet to form the OSPF backbone area and the MPLS domain. In this example, two directly connected OSPF-disabled VLANs are shown: unc and duke. Traffic between unc and duke follows routed paths over calculated LSPs established between LSR 1 and LSR 4.

The commands used to configure LSR 1 are described below. The remaining LSRs are configured similarly.

The following commands configure the module types for specific slots:

configure slot 2 module 8900-G48T-xl
configure slot 2 module 8900-G48T-xl

The following command sets the maximum jumbo frame size for the switch chassis to 1600:

configure jumbo-frame-size size 1600
enable jumbo-frame ports all

The following commands create the VLANs:

create vlan lpbk
create vlan vlan1
create vlan vlan2
create vlan unc

The following commands configure the VLAN IP address and assign ports participating in each VLAN:

configure vlan lpbk ipaddress
enable ipforwarding lpbk
enable loopback-mode lpbk
configure vlan default delete ports all
configure vlan vlan1 ipaddress
configure vlan vlan1 add port 3:2 untagged
configure vlan vlan2 ipaddress
configure vlan vlan2 add port 3:3 untagged
configure vlan unc ipaddress
configure vlan unc add port 3:4 untagged

The following commands enable IP forwarding on the configured VLANs.

The MTU size is increased on the MPLS VLANs to accommodate the MPLS shim header:

enable ipforwarding vlan vlan1
configure ip-mtu 1550 vlan vlan1
enable ipforwarding vlan vlan2
configure ip-mtu 1550 vlan vlan2
enable ipforwarding vlan unc

The following command configures the MPLS LSR ID:

configure mpls lsr-id

The following commands add MPLS support to VLANs lpbk, vlan1, and vlan2:

configure mpls add vlan lpbk
configure mpls add vlan vlan1
configure mpls add vlan vlan2

The following commands enable MPLS on VLANs lpbk, vlan1, and vlan2 and LDP on VLANs vlan1 and vlan2:

enable mpls lpbk
enable mpls vlan1
enable mpls vlan2
enable mpls ldp vlan1
enable mpls ldp vlan2

The following command allows LDP to advertise a label mapping for the LSR ID:

configure mpls ldp advertise direct lsr-id

The following commands globally enable LDP and MPLS on the switch:

enable mpls protocol ldp
enable mpls

The following commands add lpbk, vlan1, and vlan2 to the backbone area.

The (backbone) area does not need to be created because it exists by default:

configure ospf add vlan lpbk area
configure ospf add vlan vlan2 area
configure ospf add vlan vlan1 area

The following command enables distribution of local (direct) interfaces into the OSPF area:

enable ospf export direct cost 10 type ase-type-1

The following command configures the OSPF router ID on the switch and enables the distribution of a route for the OSPF router ID in the router LSA.

Originating the router ID as a host route allows other routers in the same OSPF area to establish calculated LSPs for external routes to this router:

configure ospf routerid

It also allows this router to be a peer in a L2 VPN.

The following command enables OSPF:

enable ospf