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VPN tunnel up but can't see anything on the network

VPN tunnel up but can't see anything on the network

I have a 7203dl, SROS J08.03, ROM J06.06. I've follow the instructions in 3 different documents to setup an IPSec VPN in tunnel mode. My eth 0/1 is 10.1.0.1/16. The tunnel uses an ip range of 10.100.100.1 - 10.100.100.255. I push two internal DNS's, 10.1.0.37 & 10.1.0.38 to the client.

When the tunnel comes up, I can see in the log viewer that my client gets assigned 10.100.100.1 as it's address and receives the two dns's. At this point, I can ping the router at 10.1.0.1 but that's it. I can't ping either of the dns's, 10.1.0.37 or 38, nor can I ping any other resource on the 10.1.0.0/16 network. Why is this so? I was under the impression that this tunnel would basically work as an extension of my network. This doesn't seem to be the case at all. Can anyone shed some insight?
3 REPLIES
Pieter 't Hart
Honored Contributor

Re: VPN tunnel up but can't see anything on the network

offcourse first the packets need to be received by this router. is this the default-gateway of the DNS's?

after setting up the tunnel, the system needs to know what packets may be sent over this tunnel,called "interesting trafffic".

please check subnetmasks used!
if both "10.1" and "10.100" fall within the same network (subnet). the router will see no need to pick up the packets: all traffic is local and need not be routed!

do a show access-list and show crypto-map to find out if there is traffic "interresting" to send over the tunnel.

if you specify "log" in the accesslist
>>> ip access-list extended
>>>corporate_traffic
>>>permit ip 10.10.10.0 0.0.0.255 any log
>>> deny ip any any log
it may help to track whats packets are allowed or not.

Re: VPN tunnel up but can't see anything on the network

I thought this was the default gateway for the DNS's but it turned out not to be so. I've changed them to use it. We'll see what differences that makes.

I've attached a copy of the crypto portion of my config file for you to look at.

Re: VPN tunnel up but can't see anything on the network

I finally got this working by using a virtual adapter. This is exactly the opposite of how the VPN doc has you setup the client for mode config but it's the only way I got it to work.