Outlook issues with Cisco VPN 3005 and 3.5 client

[rtiv]

My setup is the following: I have a 3005 concentrator which I recently upgrade the flash image to vpn3005-3.5.3.Rel-k9.bin. in order to support the IPSec over TCP addition (as alot of my remote users have Linksys routers doing NAT). I upgraded my clients with a mixture of version 3.5.1, 3.5.2, and 3.5.3

I'm noticing the following issues since then:

After upgrading the image on the 3005, my main user group could not connect. After changing the IPSec SA from ESP-3DES-MD5 to ESP/IKE-3DES/MD5, it worked. Since then, the following issues are taking place.

Whenever users are in MS Outlook we have a variety of things happen:
If anyone tries to attach a doc to an outgoing piece of mail, their machine hangs and eventually the IPSec connection is terminated ?
Sometimes, even just reading email in Outlook causes lose of connection.

Why did I have to change the IPSec SA method to get it to function again ?

 

[anorman]

the problem is the MTU on the pc's NIC. You'll have to ru a MTU program on each PC. The link below will help you out

http://www.cisco.com/warp/public/794/router_mtu.html

 

[rtiv]

Guess I'm confused. I just read the article you sent me to and it continuously references "web servers" "when a user requests a web page".....I'm talking about a remote user sitting at home with the cisco 3.5 VPN client setting up an IPSec tunnel to my main office which has a 3005 concentrator ??

 

[bp1169]

We had the same problem here. Anorman is correct in saying that you need to change the MTU, to do this run the setmtu.exe file that is included with the client (should be in C:\program files\cisco systems\). The mtu for your connection should be set to 1400, per recommendations from Cisco's website. Exchange likes to send overly large packets thereby causing fragmented packets to be encapsulated in new frames which in turn will cause excessive overhead for the connection,sometimes outlook will timeout as a result. Hope this helps.

For more info see

http://forums.cisco.com/eforum/serv...display_location&mode=new&location=.ee79015/2