MPLS TE load-balancing --- CEF Problem

[Sherif Atef Ahmed Ismail]

Dears

Would like your assistance please regarding below issue

We are having 5 TE tunnels going to same destination and we are doing load-balancing between these 5 LSPs TE tunnels.

Command "mls ip cef load-sharing full simple" is configured so that CEF will use L4 ports in its algorithm

Problem that due to CEF behavior, 2 link are v.highly utilized and the other 3 utilization are below average

What I am thinking of but not sure If this will help or not is to have 2 TE tunnels instead of 5

1 TE tunnel load balancing on 3 links ( This can be done by using static route to tail loopback poiting to the 3 links) and another TE tunnel load balancing on the other 2 links

By doing this, I think CEF would be used 2 times; first to determine which TE tunnel to use then to determine which link within the tunnel

Will this help ?

For example

interface Tunnel1

ip unnumbered Loopback0

mpls ip

tunnel destination 10.0.0.1

tunnel mode mpls traffic-eng

tunnel mpls traffic-eng autoroute announce

tunnel mpls traffic-eng path-option 1 dynamic

tunnel mpls traffic-eng fast-reroute

!

ip route 10.0.0.1 255.255.255.255 link-1

ip route 10.0.0.1 255.255.255.255 link-2

ip route 10.0.0.1 255.255.255.255 link-3

[Giuseppe Larosa]

Hello Sherif,

traffic of a single TE tunnel will not be load balanced over multiple physical links as the TE tunnel is setup using a reservation and the path will use only one link for each router hop.

So moving to two TE tunnels is not an option for you.

Hope to help

Giuseppe

[Sherif Atef Ahmed Ismail]

Hi Giuseppe

Yes you are totally correct ... I forgot about this issue

Many Thanks for your assistance

[chvp]

Do you have the option of using LAGs (Portchannels)

- if so then your tunnel will select one link-group instead of another but you will have loadbalancing within you LAG group.