Go CCIE Go!! - A Cisco Certified Internetwork Expert

I suspect your issue was MTU. The unreachables were reporting fragmentation needed…
A better approach is to disable unreachables, as they are considered a security risk… and to enable “ip tcp mss-adjust 1380″ on the client facing ce Interfaces, and limit the “ip mtu 1412″
You want to force the clients to use smaller mtu earlier on, to avoid “dumbbell” mtu issues as they route through the cloud.
-Joe
—–Original Message—– From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Matemane, Walter Sent: Monday, March 31, 2008 1:05 AM To: ccielab@groupstudy.com Subject: Can “no ip unreachables” commmand break Citrix traffic?
Hi Group

I had the following commands on PE to CE WAN interface and as a result users from that site had difficulties accessing Citrix applications. Citrix application will connect but when launching apps it will hang freeze eventually.

CE rtr
interface Serial0/0/0
no ip unreachables
ip route-cache flow
no ip redirects
no ip proxy-arp
no mop enabled
!
PE rtr
interface Serial0/0/1
ip vrf forwarding branch
no ip unreachables
ip route-cache flow
no ip redirects
no ip proxy-arp
no mop enabled
!

As part of troubleshooting I removed commands from the interface one by one and as soon as I removed “no ip unreachables” command the user started working without any issues. As it can be noticed I used SMD to generate this commands
Any ideas why this command break citrix? Or is it something else?

Tlatlaru W Matemane
Liberty Life

Look for the Team that Loves to Win, If you can find it look for People who Hate to Lose.

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