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TOPIC: Gre pptp through nat

Gre pptp through nat 8 years 11 months ago #24403

  • Brandonh
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I have a 2621 router and I am wanting to configure gre protocol 47 to pass through nat overload to my microsoft vpn server. I am having trouble discovering the commands to allow the gre through. My nat is set up and I have been able to allow tcp or udp fowarding to internal machines but need to allow GRE protocol 47. If someone can tell me the commands I would appreciate it thanks.
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Re: Gre pptp through nat 8 years 11 months ago #24435

  • Elohim
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Allow GRe through your access-list.
I have a 2621 router and I am wanting to configure gre protocol 47 to pass through nat overload to my microsoft vpn server. I am having trouble discovering the commands to allow the gre through. My nat is set up and I have been able to allow tcp or udp fowarding to internal machines but need to allow GRE protocol 47. If someone can tell me the commands I would appreciate it thanks.
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Re: Gre pptp through nat 8 years 11 months ago #24436

  • Smurf
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You will need to allow TCP/1723 also.

Your GRE access list would look something like this;

ip access-list 101 permit gre any any
Wayne Murphy
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Re: Gre pptp through nat 8 years 11 months ago #24452

  • Brandonh
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Thanks man I'll give that a shot I have been looking for that command for days.
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Re: Gre pptp through nat 8 years 11 months ago #24454

  • Smurf
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Obviously you can tie it down by replacing any any with source and destination addresses :)
Wayne Murphy
Firewall.cx Team Member
www.firewall.cx

Now working for a Security Company called Sec-1 Ltd in the UK, for any
Penetration Testing work visit www.sec-1.com or PM me for details.
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