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Unable to reach IP tunnel destination addresses from IOS

itdeptneci asked
Medium Priority
Last Modified: 2012-05-06

I am trying to setup a Cisco 877 router as a DNS Server. The same router has a Site to Site Tunnel setup and working between it and our main office located behind a Cisco PIX 515E.

877 (192.168.104.x) -> PIX (192.168.1.x)

I have enabled

IP DNS Server
IP name-server

Basically assigning my private DNS servers does not work. I can ping the private DNS Servers from any PC at either end of the tunnel (192.168.104.x & 192.168.1.x). However I cannot ping the Private DNS Server IP addresses or anything at 192.168.1.x from IOS at the remote side.

Cut a long story short, the reason I am trying to use my private DNS Servers as Name servers is to use split dns, I also realise that I can assign the same name servers inside a dhcp scope on the router..but again due to setting up split dns I need to do it this way.  

If only I can figure out why I cannot ping the devices or anything else at the end of the tunnel from the router itself.

Is it because the traffic is originating from the Dialer interface, and not VLAN1?

I have attached a sample copy of my config, hopefully somebody can advise where I'm going wrong!

Many Thanks,


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Sr. Systems Engineer
Top Expert 2008
>If only I can figure out why I cannot ping the devices or anything else at the end of the tunnel from the router itself.
Because your router's IP address is not included in the interesting traffic to go through the tunnel.
Try to ping from the router to the dns server and your source IP will be your outside interface IP,  not the inside interface IP. Do a source ping using the inside IP address and you will be successful. So you need to add the routers public ip to the acl that defines the crypto map match traffic (on both sides)

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Yes sorry..I since found this about 2 minutes after posting the question but forgot to close it out.

Seeing as you are the only one which replied to the message I'll give you the points.


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