This is Video #4 of our MPLS Traffic Engineering series, which is designed to help viewers gain basic understanding of MPLS Traffic Engineering and how to configure TE tunnels in Cisco routers.

In this video, we will do a lab that demonstrates how to configure explicit path for MPLS TE tunnels.

References:

http://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/TE_1208S.html

http://www.cisco.com/c/en/us/support/docs/multiprotocol-label-switching-mpls/mpls/13731-mpls-te-ospf.html

http://www.cisco.com/c/en/us/support/docs/multiprotocol-label-switching-mpls/mpls/13737-mplsteisis.html

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/mp_te_path_setup/configuration/xe-3s/mp-te-path-setup-xe-3s-book/mp-te-interarea-tun.html

Notes:

– Exclude-address is simply listing down which LSRs that will be avoided by the MPLS TE tunnel.
– Multiple exclude-address entries can be configured under IP explicit-path.
– Next-address is simply listing down the hops the tunnel LSP will take.
– Strict option means that the addresses listed is in sequence and hop by hop per LSR.
– Loose option means non-directly adjacent IP addresses can be specified and doesn’t have to specify hop by hop next-addresses.
– Under strict option, if incomplete next-addresses, the tunnel won’t come up.
-If next-address configuration did not specify an option by default strict option is selected.
– Exclude-address and next-address commands can exist in an explicit-path configuration but it will not work and will break the tunnel.

Configuration:

interface Tunnel100
tunnel mpls traffic-eng path-option 1 explicit name PATH1

ip explicit-path name PATH1 enable
exclude-address 2.2.2.2
next-address <strict/loose> 13.13.13.3