How do I pass GRE/!P47 thru the NAT (for VPN)?

  • Thread starter Thread starter medicine.man
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medicine.man

I have a W2K server behind a Flowpoint 2200 router for
VPN ... port 1723 forwarded thru the router to the
server. No problem. Tested VPN from a client across the
LAN. No problem. But won't connect thru the router from
WAN. I understand that the VPN connection needs GRE/IP47
also, but the NAT/Router only gives me forwarding options
for TCP or UDP. How do I overcome or workaround this? Any
ideas? I know this has got to be something fairly common.

Thanks inadvance for your help.
 
medicine.man said:
I have a W2K server behind a Flowpoint 2200 router for
VPN ... port 1723 forwarded thru the router to the
server. No problem. Tested VPN from a client across the
LAN. No problem. But won't connect thru the router from
WAN. I understand that the VPN connection needs GRE/IP47
also, but the NAT/Router only gives me forwarding options
for TCP or UDP. How do I overcome or workaround this? Any
ideas? I know this has got to be something fairly common.

Thanks inadvance for your help.
Click to expand...

Hmm, not sure - our router simply offers port# and ip to forward to, no
option for protocol type. Have you tried adding an entry for one/both to see
if it works?
 
Thanks James, actually I found my answer ... turns out
that the Flowpoint (Efficient Networks) OS just uses
different semantics than I'm accustomed to.

Answer: rather than TCP or UDP in the <proto> field of
the command, you insert the IP proto # (47).

Thanks again.
 
Glad you found it. As you now know, GRE is just another IP protocol like
ICMP (IP protocol 1), TCP (IP protocol 6) and UDP (IP protocol 17).
 
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