Urgent Network Help PSE

[skhips]

Please help anyone ASAP.

Two NT4 lans connected with 2 CISCO 2500 routers.

Was working fine then one day .....

After loading the weekly encryption we noticed that email above 2kbits was NOT getting through (this was all apart from the Excange 5.5 MTA info).

We tried pinging and oly 80% to 60% would get through.

Over the next 24hrs it would get better and better until we come to put the weekly encryption in again.

It seems like a timing issue, almost as if the clocks are losing it and it takes a while for them to sync,

Any thoughts,

We have Netmon installed but you really now what to look for, I would like to run netmon while pings are failing and working and compare the two results but what am i looking for in netmon.

Any thoughts or good sites.

any help is much appreciated,

in fatc just your time and patience to read this post is appreciated.