Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

PPP multilink on 6500 issues

hello everybody,

I have two problems related to multilink interfaces. I couldn't find any information about those problems in the site, I hope you be able to help me:

1. when I am tring to change the MTU size of the interface from the default (1500) to any other value, I get the following message:

% Interface Multilink1 does not support user settable mtu.

what should I do? is it software or hardware issue? I must increase the MTU to 1530 in order to run EoMPLS on this link, doing equal cost load balance cannot help me becuase I need the aggregated BW.

2. it seems that after assigning multilink-group to a multilink interface,

it is not possible to change the multilink-group of that interface.

even if I shutdown the multilink interface, then delete it with "no interface multilink1", when I reconfigure the interface, it brings back the old multilink-group.

does anyone notice this behavior too?

anyone know workaround? it is important for me to keep the multilink interface number becuase of a naming and numbering scheme we have at our network.

more information:

I am running catalyst 6500 with sup7203bxl, software version 12.2(18)SXE3 (advanced IP services)

thank you in advanced, Galit.


Re: PPP multilink on 6500 issues

Hi Galit

I did give a try changing the MTU in my 6513 box which is currently running with 12.2(18)SXD5 and it got changed to the new mtu value under the multilink interface.

Btw do revert the kinda interfaces which you are trying to bring up in the bundle.

AFAIK and from my personal exp we do have some multilink bundles running in which we do tweak the multilink group on the interfaces to bring them on some particular bundle which again worked fine for us.but not sure though with 6500 box.

Is it possible to give a try by changing the ios ?


New Member

Re: PPP multilink on 6500 issues

hello Kumar,

thank you for your response, I am sorry for my late reply, I was on hollyday untill today.

to the problems:

1. the MTU problem -

you are right, I checked it also today, other IOS versions do support the MTU change on multilinks.

but I cannot change the IOS, since 12.2(18)SXE and 12.2(18)SXF are the only versions that support all the features we need (like bgp load balancing and multicast support for MPLS VPN).

2. the group number problem -

I will check it later after I solve the more critical issues, in the worst case, we will change the numbering scheme. I thought I will find a workaround, but I guess there isn't.

thanks again, Galit.

CreatePlease login to create content