VPN keeps getting dropped almost every 10 mins.! Why?

Hi,

I have setup two VPN servers in my work environment.
The two servers sit behind a hardware firewall and
both machines are mapped to external IPs via NetScreen 25.

Each machine has two NICs and they both have Windows 2000
Server
installed (with all Microsoft's latest patches applied).
Internet
Authentication Service is installed and both machines
belongs to
a domain controller which provide authentication services
for these
VPN servers.

Since both machines have identical setup (except IP),
I will give you config of VPN Server1:

Two NICswith bogus IPs)

NIC#1Public: 192.168.1.90 mapped to 202.15.15.90
SubNet MasK 255.255.255.0
Default Gtw 192.168.1.1
Preferred DNS 192.168.1.80

NIC#2Private: 192.168.1.92
SubNet MasK 255.255.255.0
Default Gtw(blank-per MS manual i found on the Internet)
Preferred DNS 192.168.1.80

Users are prompted for password and authenticated
with no problem but only stay connected for
about 10 to 15 minutes then gets dropped
eventhough they can reconnect with no problem.
This problem persist for every user trying to VPN in.

Can someone tell me if my configuration is correct?
What can I do to rectify this?

Any help on this would be much appreciated.

Thanks In Advance,

-Exo

just fixed a similar issue last week. I would check the VPN server idle time
first.

--
For more and other information, go to http://www.ChicagoTech.net

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.

Robert Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN, Anti-Virus, Tips & Troubleshooting on
http://www.ChicagoTech.net
This posting is provided "AS IS" with no warranties.

"Exo" <(E-Mail Removed)> wrote in message
news:00f401c3deb2$6f49fa50$(E-Mail Removed)...
> Hi,
>
> I have setup two VPN servers in my work environment.
> The two servers sit behind a hardware firewall and
> both machines are mapped to external IPs via NetScreen 25.
>
> Each machine has two NICs and they both have Windows 2000
> Server
> installed (with all Microsoft's latest patches applied).
> Internet
> Authentication Service is installed and both machines
> belongs to
> a domain controller which provide authentication services
> for these
> VPN servers.
>
> Since both machines have identical setup (except IP),
> I will give you config of VPN Server1:
>
> Two NICswith bogus IPs)
>
> NIC#1Public: 192.168.1.90 mapped to 202.15.15.90
> SubNet MasK 255.255.255.0
> Default Gtw 192.168.1.1
> Preferred DNS 192.168.1.80
>
> NIC#2Private: 192.168.1.92
> SubNet MasK 255.255.255.0
> Default Gtw(blank-per MS manual i found on the Internet)
> Preferred DNS 192.168.1.80
>
> Users are prompted for password and authenticated
> with no problem but only stay connected for
> about 10 to 15 minutes then gets dropped
> eventhough they can reconnect with no problem.
> This problem persist for every user trying to VPN in.
>
> Can someone tell me if my configuration is correct?
> What can I do to rectify this?
>
> Any help on this would be much appreciated.
>
> Thanks In Advance,
>
> -Exo

Thanks for the tips, Robert. Will check on that.

-Exo
>-----Original Message-----
>just fixed a similar issue last week. I would check the
VPN server idle time
>first.
>
>--
>For more and other information, go to
http://www.ChicagoTech.net
>
>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.
>
>Robert Lin, MS-MVP, MCSE & CNE
>Networking, Internet, Routing, VPN, Anti-Virus, Tips &
Troubleshooting on
>http://www.ChicagoTech.net
>This posting is provided "AS IS" with no warranties.
>
>"Exo" <(E-Mail Removed)> wrote in message
>news:00f401c3deb2$6f49fa50$(E-Mail Removed)...
>> Hi,
>>
>> I have setup two VPN servers in my work environment.
>> The two servers sit behind a hardware firewall and
>> both machines are mapped to external IPs via NetScreen
25.
>>
>> Each machine has two NICs and they both have Windows
2000
>> Server
>> installed (with all Microsoft's latest patches applied).
>> Internet
>> Authentication Service is installed and both machines
>> belongs to
>> a domain controller which provide authentication
services
>> for these
>> VPN servers.
>>
>> Since both machines have identical setup (except IP),
>> I will give you config of VPN Server1:
>>
>> Two NICswith bogus IPs)
>>
>> NIC#1Public: 192.168.1.90 mapped to 202.15.15.90
>> SubNet MasK 255.255.255.0
>> Default Gtw 192.168.1.1
>> Preferred DNS 192.168.1.80
>>
>> NIC#2Private: 192.168.1.92
>> SubNet MasK 255.255.255.0
>> Default Gtw(blank-per MS manual i found on the Internet)
>> Preferred DNS 192.168.1.80
>>
>> Users are prompted for password and authenticated
>> with no problem but only stay connected for
>> about 10 to 15 minutes then gets dropped
>> eventhough they can reconnect with no problem.
>> This problem persist for every user trying to VPN in.
>>
>> Can someone tell me if my configuration is correct?
>> What can I do to rectify this?
>>
>> Any help on this would be much appreciated.
>>
>> Thanks In Advance,
>>
>> -Exo
>
>
>.
>