Which ports for IPSEC/LT2P?

Posted by Matt on Server Fault See other posts from Server Fault or by Matt
Published on 2012-11-22T22:56:01Z Indexed on 2012/11/22 23:00 UTC
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linux

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iptables

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firewall

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ipsec

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l2tp

I have a firewall/router (not doing NAT).

I've googled and seen conflicting answers. It seems UDP 500 is the common one. But the others are confusing. 1701, 4500.

And some say I need to also allow gre 50, or 47, or 50 & 51.

Ok, which ports are the correct ones for IPSec/L2TP to work in a routed environment without NAT? i.e. I want to use the built in windows client to connect to a VPN behind this router/firewall.

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