Global Protect on overlapping networks

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Highlighted
L1 Bithead

Global Protect on overlapping networks

Hello everybody!

I have a big problem with Global Protect and overlapping networks.

I make you an example.

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My local network is 192.168.10.x

My Global Protect Network is 172.16.x.x

The external network has the same class of my local network

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If I connect my lapton in any networks everything works good but if the network has the same class of my local network Global Protec Client on my laptop discover the "outside network" like extenal network (perfect thing) but if I try to access some service like webserver or Exchange I encounter connection error.

Can I resolve this specific situation? How?

Another think ... I can resolve and ping for example my internal DNS

Help me please ....


Accepted Solutions
Highlighted
L7 Applicator

Re: Global Protect on overlapping networks

This is by design: if the GP client is located in a network that is identical to the one used in the VPN tunnel (let's call it localnet vs officenet) all traffic will be pushed into the tunnel

If the localnet is a subnet of officenet (so localnet/24 vs officenet/21) the more specific network will "win" the route so local resources remain reachable

In this case if there is an IP overlap where a local resource uses the same IP as a remote resource, the local resource will be reachable and the remote not.

In case of an identical subnet (/24 vs/24) remote resources will be available while local ones will not be

reaper - PANgurus.com
I drink and I know things

View solution in original post


All Replies
Highlighted
L3 Networker

Re: Global Protect on overlapping networks

You are hitting your external gateway fine, but are unable to access internal resources?  Is this correct?

Highlighted
L3 Networker

Re: Global Protect on overlapping networks

A couple places to look for a problem.

  • Check to make sure that you have a security rule in place from inside to outside with your IP range for the GP pool. And vice versa.
  • Check that you have a route in place on your vrouter to allow you to stay inside once you have connected to the GP client.

Could you upload images of your vrouter and interfaces?

Also, make sure that your IP pool that you are assigning clients from GP is not the same network as your internal resources.  It has to be something different.

Highlighted
L1 Bithead

Re: Global Protect on overlapping networks

Yes ... but only some address. For Example the DNS server works good.

I think I've find the error. I've missed the Access Route in Gateway configuration.

Highlighted
L3 Networker

Re: Global Protect on overlapping networks

That'll do it.  Let me know if that fixes it.  If you just enter 0.0.0.0 in the access routes for the Gateway, that will take care of it.

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L1 Bithead

Re: Global Protect on overlapping networks

If I use 0.0.0.0/0 or leave everything blank I have the overlapping problem.

If I submit my network class everything works but I cannot block for example the web-browsing because I bypass my firewall for navigation.

Highlighted
L3 Networker

Re: Global Protect on overlapping networks

Does your vrouter have a route to internal resources?

Highlighted
L1 Bithead

Re: Global Protect on overlapping networks

Do you mean I have to create I single route for I single resource in VR?

Highlighted
L3 Networker

Re: Global Protect on overlapping networks

No not necessarily.  For instance, I have 2 rules on my Vrouter for 172 and 192 addresses that point them from my external interface to my internal gateway.

Highlighted
L3 Networker

Re: Global Protect on overlapping networks

Here is what my vrouter looks like:

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