site to site vpn help

Answered Question
Aug 12th, 2008
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I'm trying to build site to site vpn using two 5520s. Two ASAs are sitting behind edge Cisco routers. To allow ASAs have site to site VPN, what port do I have to allow on the router to pass VPN traffic? I have to allow remote FW IP to connect to local FW IP. Port 50,51 and 500?


Correct Answer by acomiskey about 8 years 9 months ago


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Daniel Voicu Tue, 08/12/2008 - 09:38
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Yes, you got them all: IP ports 50 and 51 and UDP port 500. Also leave the ICMP ports opened between the IPs for the PathMTU Dicovery.

Please rate if this helped.



acomiskey Tue, 08/12/2008 - 10:02
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Careful not to get mixed up by ports 50 and 51 and ip protocols 50 and 51. You need ip protocol 50(esp) and udp port 500.

peterhkim Tue, 08/12/2008 - 10:12
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So, I need access-list setup on the router to allow udp port 500 and ip protocol 50.

Did I get this right?


Correct Answer
acomiskey Tue, 08/12/2008 - 10:42
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