This is Video #3 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 manipulate the dynamic path selection process.

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:

– MPLS administrative weight is the TE metric.
– By default the administrative weight or TE metric is equal to the IGP metric.
– IS-IS uses a default metric of 10 to all interfaces.
– To change IS-IS metric issue command “isis metric ” under the interface level configuration.
– Change TE metric by using “mpls traffic-eng administrative-weight ” under the interface level configuration.
– The lesser the metric the better.
– To change tunnel path, sometimes it can be done simply by flapping the tunnel interface.
– The tunnel can make use of IGP metric instead of TE metric by configuring “tunnel mpls traffic-eng path-selection metric igp” command under the tunnel interface.

Configuration:

interface GigabitEthernet0/x
mpls traffic-eng administrative-weight 
isis metric 

interface Tunnel100
tunnel mpls traffic-eng path-selection metric <igp/te>