Strange MTU issue

[boymarty24]

Hi guys,

I have some strange issues that i am pretty sure is related to MTU.

I have to 1811 routers connected via site to site VPN. The tunnel works fine. What doesnt work is the AD replication/domain login, and from reading forums and techsites this is related to MTU. I have tried to set the mtu size on both routers but cant get it to work ( fragmentation error!?!? ) did ping -f -l and the mtu goes up and down.

Anyone who can point me in the right direction? What should the syntax look like on the routers to get it to work.

Can it be a ios image deal? Router hardware? ISP?

 

[boymarty24]

I am solving this one =)

It was a ios issue. Tried the latest ios but that didnt work so i rolled back to one release before that and then it worked

 

[Supergrrover]

I hate that!! If it worked in one release, it should work in all that follow. This happens with PIX/ASA as well.


Brent
Systems Engineer / Consultant
CCNP, CCSP

 

[boymarty24]

Agree 100%

The strange thing with this was that the ios image that was shipped with the isr1812 handled this well but not pptp connections to MS servers. the latest ios solved the pptp issue but broke my site to site vpn. So the ios image couple of releases back worked.

This release is the best for 870/871/1811/1812 series
advipservicesk9-mz.124-9.T2.bin