Microsoft NLB cluster through Cisco VPN tunnel

We have 2 Win 2003 servers in a Unicast NLB Cluster.
Each server has it's own IP address and the cluster has it's own IP address.
We have established a Cisco VPN tunnel between and 877 and an 878 router using the SDM interface.

Remotely, we can access each server individually but not by the cluster IP address.
Remotely, we can ping each server but not the cluster IP address.
Locally, everything works fine, and the cluster IP address responds fine.
Who is Participating?
nmxsupportConnect With a Mentor Author Commented:
I am requesting closure on this question.
After speaking with Cisco there was 2 main issues.
1) the mtu packet size needed to reduced from 1500 on the routers - apparently RDP is affeced by this?I've not heard of this but this got IP working.
2) because RDP was already being natted on the external interface it was not being passed back through the vpn tunnel, we had to add an exception to the natting rules/vpn tunnel to get rdp to return back through the vpn tunnel if it started there.
Are you pointing the NAT in your firewall to the NLB IP ?
Check the default gateway setting on the cluster IP config
Closed, 500 points refunded.
Community Support Moderator
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.