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JammyPakFlag for Canada

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IPSec VPN connection from behind a PAT firewall?

Hi folks,

I know that I cannot create a outbound PPTP-based VPN connection from behind my PAT firewall (Cisco PIX) without creating static mappings between the internal (private) and an external (public) address. Obviously this isn't feasible, since I would need to have a separate public address for everyone who needs/wants to make an outbound VPN connection, and I'd need to setup static mappings for each address.

However; can anyone confirm or deny whether this is possible when using IPSec to create the firewall connection?

Basically, I would like to have a way to allow people from behind my firewall to make a VPN connection to another office, ideally without 1-1 address mapping. I don't want to have a LAN-LAN VPN tunnel, I want it PC-LAN.

Thanks!
JP
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_nn_

I don't see how. IPSec needs UDP 500 and IP proto 50/51. In a sense, it's "IP-in-IP", so AFAIK, it can't work through a PAT.
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t1n0m3n

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BTW the default TCP port for IPSec over TCP is port 10000.
Basically, the protocol 50 (and 51 if you are using AH) will get encapsulated in a TCP packet and look like normal TCP/IP traffic to the NAT device.

NAT should read PAT
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ASKER

Hi folks, thanks for the responses.

t1n0m3n, I'll try this out and let you know how it goes!
Seems to work great - thanks!