I'm having an issue with an ASA 5510 and a Remote Access VPN setup. The VPN Client can connect fine, and after that it can connect to the servers behind the ASA with no problems and no speed issues.
However, when the user tries to connect to something outside of the split-tunnel (such as google.com, yahoo.com, cisco.com, etc) it is extremely slow. Pages that take 1-2 seconds to load take 30 seconds to load. This traffic isn't going through the ASA at all so I don't understand why it would be affected. But the moment the user disconnects from the VPN Client, speed to external sites is restored.
This makes me feel like it's a MTU or Speed/Duplex problem on one end. The MTU of the ASA's outside interface is 1500, and the interaces are 100/Full (I'm working on an upgrade for the ASA that will apparently unlock the FastEthernet ports to GigE ports).
I did some additional investigation and found that this issue was related only to users of Microsoft Vista SP1. After that, I read around about some issues that Service Pack 1 for Vista had on the Cisco VPN client. I uninstalled the VPN Client on each machine having the problem and installed the latest version and it fixed the problem.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...