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i configured a VPN server with IPsec to surfe secure at public networks. At generally it works. Now i would like to access my vpn server from my campus. Here i can't get any connection.

I know, that the campus administrator block all ports under 1024 except http and https. I also know, that IPsec use UDP 500 and 4500.

  1. Do you think it is enough to change the port UDP 500 to a higher port? Are there other ports important for IPsec under 1024?
  2. Does IPsec work with TCP instead UDP?
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up vote 1 down vote accepted
  1. IPsec has 2 phases, the first phase involves IKE(aka ISAKMP) protocol which uses udp port 500.Port 4500 is only used when dealing with nat traversal.

  2. The standard defines the phase 1 using udp protocol, and the software is implemented in the same manner.

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If I understand that correctly, i can only change the port 500 higher and hope that they will not block UDP or switch to for example openvpn. Greetz. – hofmeister Jan 28 '12 at 10:27
yes,i believe so. – frankcui24 Jan 28 '12 at 14:24

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