I'm having some problems using the VPN Client with a dial-up Internet connection. When i start the VPN Client to access my company's LAN my regular Internet access goes unavailable. I think it mite be related with the MTU configuration but i'm not sure.
Probably nothing to do with MTU - more likely you haven't got split tunnelling enabled.
Be default Cisco VPN Head Ends publish a default route to their VPN clients - meaning that once the tunnel is active the client will send ALL traffic over the tunnel - including your normal Internet stuff. Thus you can access the Internal networks, but not the Internet.
Enabling split tunnelling allows you to only publish the Internal networks that the VPN Head End is protecting to the client - meaning that you can access these, and the Internet, at the same time.
Split runneling is supported on all VPN Head End platforms (IOS, VPN Concentrator, PIX) - and the configuration is slightly different for each. If you let me know what your head end is, I can give you some pointers.
access-list 101 permit ip 18.104.22.168 255.255.255.0 any
access-list 101 permit ip 22.214.171.124 255.255.255.0 any
The above would cause the PIX to only publish to the VPN client the 126.96.36.199 and 188.8.131.52 subnets. This means that the client will only tunnel traffic destined to these networks to the PIX - and will send any other traffic directly to the Internet.
Note that this does open the possibility of security exposures on your client - thus the use of a PC firewall product is strongly recommended.
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...
[toc:faq]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 and UDP are I...