Proxy & VPN

[Guest]

Hello everybody!

OS = XP SP2

By GPO th IE ist told to use a proxyserver (ISA2004).

Users are not allowed to leave the corporate network for internet traffic
without using the proxy, spezified on the firewall.

Administrative Computers are allowed, for testing reasons, but normally
still use the proxy. Administrative Computers are also allowd to establish
VPN connections outside. (Simple PPTP MS VPN)

Leaving the corportate network for Internettraffic over the proxy server
makes the outside world see a different IP than leaving it just over the
firewall, thats the reason why I found out th efollwing issue:

What happened is, I established a VPN connection outside and was using IE at
the same time. Although the IE was correctly configured to use the proxy
server, it didn´t, but went straight throught the firewall. As soon as i
disconnected the VPN connection, everything was fine again. This issue did
not happen when trying the same thing with firefox.

Does anybody know reasons for that?

Thanks,

Michael

 

[Leythos]

Hello everybody!

OS = XP SP2

By GPO th IE ist told to use a proxyserver (ISA2004).

Users are not allowed to leave the corporate network for internet traffic
without using the proxy, spezified on the firewall.

Administrative Computers are allowed, for testing reasons, but normally
still use the proxy. Administrative Computers are also allowd to establish
VPN connections outside. (Simple PPTP MS VPN)

Leaving the corportate network for Internettraffic over the proxy server
makes the outside world see a different IP than leaving it just over the
firewall, thats the reason why I found out th efollwing issue:

What happened is, I established a VPN connection outside and was using IEat
the same time. Although the IE was correctly configured to use the proxy
server, it didnÂ=3Ft, but went straight throught the firewall. As soon as i
disconnected the VPN connection, everything was fine again. This issue did
not happen when trying the same thing with firefox.

Does anybody know reasons for that?

When you VPN outbound you abandon your internal network and use the VPN
tunnel - simplistic way to look at it. You can't use your internal
resources.

When you use FF, it doesn't know about the proxy and will work just
fine.

IE can't reach the Proxy while your VPN is active.

 

[Guest]

Hello Leythos,

thanks for your reply.

I found out the same, what you were writing.

Now I don´t know wheater to be surprised, or see the benefits from this issue.

Anyway, I do can reach the proxyserver, even if the VPN is connected, as
long as I change the advanced TCP/IP settings of this VPN connection. (take
off the hook at "using remotegateway...)

again, thanks for your reply!

Michael