Error 721 from certain locations

After I implemented VPN on my Server 2K3 SBS, some clients could not connect
from certain locations. For example, I can connect at school, but not at my
apartment. The error that users are getting is Error 721.
What could be the issue?

Thanks,

Sean Vreeland

it could be the GRE issue. check this troubleshooting page, http://www.howtonetworking.com/VPN%20process.htm


Don't send e-mail or reply to me except you need consulting services. Posting on MS newsgroup will benefit all readers and you may get more help.

Bob Lin, MS-MVP, MCSE & CNE
How to Setup Windows, Network, Remote Access on http://www.HowToNetworking.com
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
This posting is provided "AS IS" with no warranties.
I recommend Brinkster for web hosting!

"SeanVree" <(E-Mail Removed)> wrote in message news:4786A0ED-F3C8-446F-9FDF-(E-Mail Removed)...

After I implemented VPN on my Server 2K3 SBS, some clients could not connect
from certain locations. For example, I can connect at school, but not at my
apartment. The error that users are getting is Error 721.
What could be the issue?

Thanks,

Sean Vreeland

As Bob said, it is almost certainly a GRE problem.

With a PPTP connection, the encrypted data is transferred inside a
packet with a GRE header. GRE (Generic Routing Encapsulation) is IP protocol
47.

If anything in the path (routers, firewalls, ISPs etc) blocks GRE, the
connection fails because no data is transferred.

"Robert L [MS-MVP]" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
it could be the GRE issue. check this troubleshooting page,
http://www.howtonetworking.com/VPN%20process.htm


Don't send e-mail or reply to me except you need consulting services.
Posting on MS newsgroup will benefit all readers and you may get more help.

Bob Lin, MS-MVP, MCSE & CNE
How to Setup Windows, Network, Remote Access on
http://www.HowToNetworking.com
Networking, Internet, Routing, VPN Troubleshooting on
http://www.ChicagoTech.net
This posting is provided "AS IS" with no warranties.
I recommend Brinkster for web hosting!

"SeanVree" <(E-Mail Removed)> wrote in message
news:4786A0ED-F3C8-446F-9FDF-(E-Mail Removed)...

After I implemented VPN on my Server 2K3 SBS, some clients could not
connect
from certain locations. For example, I can connect at school, but not at
my
apartment. The error that users are getting is Error 721.
What could be the issue?

Thanks,

Sean Vreeland

Mr. Grant:

That is understandable. Now since the problem only occurs at certain
locations, do you think that this could be a problem on the side of the
failing client? For example, I cannot connect at my apartment, so is it
possible that there is a router or firewall in the way?

Thanks,

Sean

"Bill Grant" wrote:

> As Bob said, it is almost certainly a GRE problem.
>
> With a PPTP connection, the encrypted data is transferred inside a
> packet with a GRE header. GRE (Generic Routing Encapsulation) is IP protocol
> 47.
>
> If anything in the path (routers, firewalls, ISPs etc) blocks GRE, the
> connection fails because no data is transferred.
>
> "Robert L [MS-MVP]" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> it could be the GRE issue. check this troubleshooting page,
> http://www.howtonetworking.com/VPN%20process.htm
>
>
> Don't send e-mail or reply to me except you need consulting services.
> Posting on MS newsgroup will benefit all readers and you may get more help.
>
> Bob Lin, MS-MVP, MCSE & CNE
> How to Setup Windows, Network, Remote Access on
> http://www.HowToNetworking.com
> Networking, Internet, Routing, VPN Troubleshooting on
> http://www.ChicagoTech.net
> This posting is provided "AS IS" with no warranties.
> I recommend Brinkster for web hosting!
>
> "SeanVree" <(E-Mail Removed)> wrote in message
> news:4786A0ED-F3C8-446F-9FDF-(E-Mail Removed)...
>
> After I implemented VPN on my Server 2K3 SBS, some clients could not
> connect
> from certain locations. For example, I can connect at school, but not at
> my
> apartment. The error that users are getting is Error 721.
> What could be the issue?
>
> Thanks,
>
> Sean Vreeland
>
>
>

Probably. Are you on some sort of residential network?

"SeanVree" <(E-Mail Removed)> wrote in message
news:AF3D0064-C0F0-4B10-B8E0-(E-Mail Removed)...
> Mr. Grant:
>
> That is understandable. Now since the problem only occurs at certain
> locations, do you think that this could be a problem on the side of the
> failing client? For example, I cannot connect at my apartment, so is it
> possible that there is a router or firewall in the way?
>
> Thanks,
>
> Sean
>
> "Bill Grant" wrote:
>
>> As Bob said, it is almost certainly a GRE problem.
>>
>> With a PPTP connection, the encrypted data is transferred inside a
>> packet with a GRE header. GRE (Generic Routing Encapsulation) is IP
>> protocol
>> 47.
>>
>> If anything in the path (routers, firewalls, ISPs etc) blocks GRE,
>> the
>> connection fails because no data is transferred.
>>
>> "Robert L [MS-MVP]" <(E-Mail Removed)> wrote in message
>> news:(E-Mail Removed)...
>> it could be the GRE issue. check this troubleshooting page,
>> http://www.howtonetworking.com/VPN%20process.htm
>>
>>
>> Don't send e-mail or reply to me except you need consulting services.
>> Posting on MS newsgroup will benefit all readers and you may get more
>> help.
>>
>> Bob Lin, MS-MVP, MCSE & CNE
>> How to Setup Windows, Network, Remote Access on
>> http://www.HowToNetworking.com
>> Networking, Internet, Routing, VPN Troubleshooting on
>> http://www.ChicagoTech.net
>> This posting is provided "AS IS" with no warranties.
>> I recommend Brinkster for web hosting!
>>
>> "SeanVree" <(E-Mail Removed)> wrote in message
>> news:4786A0ED-F3C8-446F-9FDF-(E-Mail Removed)...
>>
>> After I implemented VPN on my Server 2K3 SBS, some clients could not
>> connect
>> from certain locations. For example, I can connect at school, but not
>> at
>> my
>> apartment. The error that users are getting is Error 721.
>> What could be the issue?
>>
>> Thanks,
>>
>> Sean Vreeland
>>
>>
>>

Yeah, it's some type of LAN.


"Bill Grant" wrote:

> Probably. Are you on some sort of residential network?
>
> "SeanVree" <(E-Mail Removed)> wrote in message
> news:AF3D0064-C0F0-4B10-B8E0-(E-Mail Removed)...
> > Mr. Grant:
> >
> > That is understandable. Now since the problem only occurs at certain
> > locations, do you think that this could be a problem on the side of the
> > failing client? For example, I cannot connect at my apartment, so is it
> > possible that there is a router or firewall in the way?
> >
> > Thanks,
> >
> > Sean
> >
> > "Bill Grant" wrote:
> >
> >> As Bob said, it is almost certainly a GRE problem.
> >>
> >> With a PPTP connection, the encrypted data is transferred inside a
> >> packet with a GRE header. GRE (Generic Routing Encapsulation) is IP
> >> protocol
> >> 47.
> >>
> >> If anything in the path (routers, firewalls, ISPs etc) blocks GRE,
> >> the
> >> connection fails because no data is transferred.
> >>
> >> "Robert L [MS-MVP]" <(E-Mail Removed)> wrote in message
> >> news:(E-Mail Removed)...
> >> it could be the GRE issue. check this troubleshooting page,
> >> http://www.howtonetworking.com/VPN%20process.htm
> >>
> >>
> >> Don't send e-mail or reply to me except you need consulting services.
> >> Posting on MS newsgroup will benefit all readers and you may get more
> >> help.
> >>
> >> Bob Lin, MS-MVP, MCSE & CNE
> >> How to Setup Windows, Network, Remote Access on
> >> http://www.HowToNetworking.com
> >> Networking, Internet, Routing, VPN Troubleshooting on
> >> http://www.ChicagoTech.net
> >> This posting is provided "AS IS" with no warranties.
> >> I recommend Brinkster for web hosting!
> >>
> >> "SeanVree" <(E-Mail Removed)> wrote in message
> >> news:4786A0ED-F3C8-446F-9FDF-(E-Mail Removed)...
> >>
> >> After I implemented VPN on my Server 2K3 SBS, some clients could not
> >> connect
> >> from certain locations. For example, I can connect at school, but not
> >> at
> >> my
> >> apartment. The error that users are getting is Error 721.
> >> What could be the issue?
> >>
> >> Thanks,
> >>
> >> Sean Vreeland
> >>
> >>
> >>
>
>
>

Then it probably has a firewall/router between it and the Internet. That
is probably where GRE is blocked.

"SeanVree" <(E-Mail Removed)> wrote in message
news:88CCBED5-4D4E-484E-9C8F-(E-Mail Removed)...
> Yeah, it's some type of LAN.
>
>
> "Bill Grant" wrote:
>
>> Probably. Are you on some sort of residential network?
>>
>> "SeanVree" <(E-Mail Removed)> wrote in message
>> news:AF3D0064-C0F0-4B10-B8E0-(E-Mail Removed)...
>> > Mr. Grant:
>> >
>> > That is understandable. Now since the problem only occurs at certain
>> > locations, do you think that this could be a problem on the side of the
>> > failing client? For example, I cannot connect at my apartment, so is
>> > it
>> > possible that there is a router or firewall in the way?
>> >
>> > Thanks,
>> >
>> > Sean
>> >
>> > "Bill Grant" wrote:
>> >
>> >> As Bob said, it is almost certainly a GRE problem.
>> >>
>> >> With a PPTP connection, the encrypted data is transferred inside a
>> >> packet with a GRE header. GRE (Generic Routing Encapsulation) is IP
>> >> protocol
>> >> 47.
>> >>
>> >> If anything in the path (routers, firewalls, ISPs etc) blocks GRE,
>> >> the
>> >> connection fails because no data is transferred.
>> >>
>> >> "Robert L [MS-MVP]" <(E-Mail Removed)> wrote in message
>> >> news:(E-Mail Removed)...
>> >> it could be the GRE issue. check this troubleshooting page,
>> >> http://www.howtonetworking.com/VPN%20process.htm
>> >>
>> >>
>> >> Don't send e-mail or reply to me except you need consulting services.
>> >> Posting on MS newsgroup will benefit all readers and you may get more
>> >> help.
>> >>
>> >> Bob Lin, MS-MVP, MCSE & CNE
>> >> How to Setup Windows, Network, Remote Access on
>> >> http://www.HowToNetworking.com
>> >> Networking, Internet, Routing, VPN Troubleshooting on
>> >> http://www.ChicagoTech.net
>> >> This posting is provided "AS IS" with no warranties.
>> >> I recommend Brinkster for web hosting!
>> >>
>> >> "SeanVree" <(E-Mail Removed)> wrote in message
>> >> news:4786A0ED-F3C8-446F-9FDF-(E-Mail Removed)...
>> >>
>> >> After I implemented VPN on my Server 2K3 SBS, some clients could not
>> >> connect
>> >> from certain locations. For example, I can connect at school, but
>> >> not
>> >> at
>> >> my
>> >> apartment. The error that users are getting is Error 721.
>> >> What could be the issue?
>> >>
>> >> Thanks,
>> >>
>> >> Sean Vreeland
>> >>
>> >>
>> >>
>>
>>
>>