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Contributor
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Registered: ‎03-16-2012
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VPN up, can't ping gateway

[ Edited ]

Hello,

 

I received a SSG5 router to play around with and get my feet wet in the world of routing.  I configured a dialup VPN and I can get the client to connect and get an IP address, but I cannot ping the default gateway.  Also, the VPN session only stays up for about 3 minutes then the security association expires.  Not sure about that one either.  Any help is greatly appreciated.

Super Contributor
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Re: VPN up, can't ping gateway

I'm assuming that by "default gateway" you mean the xx.xx.xx.1 address listed as gateway for eth0/0.

 

So, you have the gateway address of xx.xx.xx.1 in the Untrust zone, and the VPN client in the Untrust zone as well, but your dial-up VPN policy is for traffic between zone Untrust and Trust, hence there's no policy to facilitate traffic between the VPN client and the default gateway.

 

The SA would normally expire if there's no traffic (e.g. real traffic, or keep-alives, or something else). Depending on the client, it can be "dialed up" again when there's a need. To see if there's a problem, try, for example, pinging continuously an IP in your Trust zone from the VPN client, and see if the SA will get destroyed while doing that.

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Re: VPN up, can't ping gateway

Thanks for the response.  If the VPN is up and I have an IP, wouldn't I be able to ping the VPN router at 172.168.1.1?  That was the test I was trying to perform.

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Re: VPN up, can't ping gateway

I think you should be able to. But you're missing set interface bgroup0 manage ping.

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Re: VPN up, can't ping gateway

Thank you, I'll give that a shot and report back with my findings.

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Re: VPN up, can't ping gateway

No, I'm still unable to ping 172.168.1.1 or any IP in the trust zone.  I did notice this notification pop up on the SSG5 monitor:  VPN monitoring for VPN <vpnclient_tunnel> has deactivated the SA with ID 0x00008C.  Could this have something to do with the VPN dropping the client after a couple of minutes?

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Re: VPN up, can't ping gateway

What is the VPN client you're using? Could you please post the IP address of the client (not the VPN-assigned one) and a trace-route between the client and 172.168.1.1 before and after VPN is established.

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Re: VPN up, can't ping gateway

I'm using Shrewsoft as the client.  If there's a better one out there, let me know.  As far as the traceroutes go, there isn't much to say.  Before the VPN connection, it gets out to the internet and dies and when the VPN is connected, it doesn't go anywhere.

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Re: VPN up, can't ping gateway

Sorry, the client IP address before connection to the VPN is 192.168.1.64.

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Re: VPN up, can't ping gateway

You can check out the NetScreen Remote VPN Client, just in case something's up with the VPN client you're using now.

Also, you can enable logging on your VPN policies and see if the traffic gets logged there.

Then, try pinging something on the inside of the firewall (172.168.1.x).

Finally, we may need to run a debug session on the firewall to see what really is happening there.
Distinguished Expert
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Registered: ‎11-02-2009
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Re: VPN up, can't ping gateway

Hi,

 

Have you correctly configured what is named Topology in the SchrewSoft VPN client? This is step 9 in the KB22074.

VPN monitoring with default settings will not work with SchrewSoft client. It will permanently drop and re-negotiate the SAs. You should select Trust interface as the source one for VPN monitoring. The Trust interface IP should belong to the topology (VPN Proxy ID) for this to work.

Kind regards,
Edouard
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Re: VPN up, can't ping gateway

Thanks for the information Edouard, but if I follow step 9 in that bulletin, I don't get any security associations to establish.  If I require a Policy Generation, I'll get one to establish, but only for a couple of minutes.  I'll rebuild my VPN client to match the bulletin posted and retry.  Nikolay, I've got the logging turned on for the policies I have configured.  How do I check the logs and see what's going on with those?  Thanks for sticking with me on this.  I'm learning a lot.

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Re: VPN up, can't ping gateway

The Web UI of the firewall has a great visual display. Login to the firewall with a web browser, navigate to Policies, find your policy and click on the little table-like icon. That will give you the log for that policy. You may want to also enable logging at the beginning of the session.

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Re: VPN up, can't ping gateway

Hi,

 

From the trace-route, it looks that the VPN client is unable to push traffic through the tunnel.

Try looking at the configuration of client, if possible, provide screenshot of client configuration.

Also, for initial analysis, you can disable monitoring (to keep things simple)

 

 

Regards.

Hardeep

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Re: VPN up, can't ping gateway

Hi,

 

The Proxy IDs are automatically derived from the VPN-policy if policy-based VPN is used. If the incoming VPN policy contains a single address object in its destination field, e.g. 192.168.1.0/24, and multiple protocols or "Any" the following Proxy ID will be used on the FW: Local IP 192.168.1.0/24 Remote IP 255.255.255.255/32 Protocol Any. If the destination field contains multiple address objects or a group of objects the Local IP will be 0.0.0.0/0. If you need an access to multiple LANs you should configure multiple VPN policies, one policy for each pair of Local IP-Remote IP. In this case I would recommend to use ScreenOS 6.3 and route-based VPN.

The Proxy ID (IDs) configured on the client should match those on the Firewall.

 

Kind regards,
Edouard
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Re: VPN up, can't ping gateway

Thanks for all the comments, but it looks like I'm moving backwards in my configuration.  Is Policy based routing the way to go?  I guess at this point, I just want the tunnel to come up and be able to move around on the trust network.  I'm willing to try a different approach if need be.  A simple setup will work.  I can always add more security as I learn more about the device and policies.  I'm really just frustrated right now and will try anything to move forward again.  Thanks again.

 

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Re: VPN up, can't ping gateway

I followed the instructions in KB22074 for the Shrew Soft VPN client.  Now, I can't even bring the tunnel up.  Before, I was able to bring the tunnel up, but the security assocations never established.  Here is a snapshot of the event log.  If anyone has ideas, let me know.  I'll be happy to share any configs or snapshots you think might help out.

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Re: VPN up, can't ping gateway

Hi,

 

You should create an IP pool. An IP from this pool will be assigned to the client during the extended authentication (XAUTH). The pool can be mapped to the default XAUTH settings (VPNs -> AutoKeys Advanced -> XAuth settings), to the Gateway Configuration or to the user profile. The settings in the user profile override those in the GW configuration and the last override the default settings. The same rule holds true for the DNS and WINS server IPs which can be assigned the same way.

You can also assign static IPs to each user in the user profile. This is usually used if the access policies are very restrictive and each user should have has a specific set of access rights.

 

Kind regards,
Edouard
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Re: VPN up, can't ping gateway

(continued) ... and route-based VPN is used.

Kind regards,
Edouard
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Re: VPN up, can't ping gateway

Hi Edouard,

 

I've tried various ways of configuring this router.  I even started from scratch and rebuilt the whole thing.  I'm convinced I have some sort of problem with my policies and the configuration of the client.  How does DNS figure into this?  I haven't added anything as far as DNS entries into the VPN, just the DNS on the untrust interface (ethernet 0/0).  I still can't get a security association to come up using the knowledge base you suggested in previous posts with the Shrewsoft client.  That's my first problem and the one I need to concentrate on.  My knowledge of subnetting has hampered this process as I am just starting out, so here's what I can tell you.  The trust zone is set for 172.168.1.0/24.  The VPN IP pool starts at 172.168.3.10.  I know that the VPN needs to be on a different subnet than the trust zone or internal LAN.  Can you please give me an idea of how the policies need to be set up?  I don't need any special permissions or anything.  I just need the VPN connection to be able to access the 172.168.1.0/24.

 

Thanks again for your help,

Rick