Error 721 Though GRE opened 1723 forwarded

[Ola]

Hello again, I am having the worst time connecting to my
VPN server.

I am trying to connect from work to my home Server. I
also should tell you that my work network is huge and
uses DHCP to assign IP to my work PC. (I do not think
that should matter but then..)

I am using the linksys DSL VPN Firewall router. I have
gone through the filter sets and added GRE port 47 and
enable PPTP passthrough and forwarded Port 1723 to my VPN
server address.

When I tried to make a connection from my office this
Morning I get

Error 721: The remote computer did not respond.

I have tried using a FQDM like abc.abcllc.com where abc
is the Server name and the domain is abcllc.com. I also
tried using the public IP address to get to the server
and I still got error 721.

Please someone help, I am seriously running out of time

Thanks in advance

 

[Sharoon Shetty K [MSFT]]

GRE is not TCP based, so you cannot use port forwarding. GRE is a protocol,
just as TCP is a protocol. TCP is IP protocol 6, UDP is IP protocol 17, GRE
is IP protocol 47. You do not forward anything. You just need to make sure
that your router does not block it. Look at the router's filter setup and
look for GRE by name or by protocol number. Or check the router
manufacturer's site for info on how to allow GRE.

 

[zillah]

GRE is not TCP based, so you cannot use port forwarding. GRE is a protocol,
just as TCP is a protocol. TCP is IP protocol 6, UDP is IP protocol 17, GRE
is IP protocol 47. You do not forward anything. You just need to make sure
that your router does not block it. Look at the router's filter setup and
look for GRE by name or by protocol number. Or check the router
manufacturer's site for info on how to allow GRE.

Nice one I learned something new