Cisco VPN client Mac 10.6 does not work

mac-osxvpn

I have a problem with Cisco VPN client v. 4.9.01.0180 on Mac 10.6 (Snow Leopard).
I'm connecting using TCP, connection is established well, but after that my internet connection just stop working, looks like there is a problem with resolving hosts – I can ping google.com's IP but not www.google.com, also VPN connection does not work as I cannot access remote addresses.

Do you have any idea what could be wrong?

Thanks in advance!

Pavol.

Best Answer

This sounds like you have a problem with your DNS once the tunnel is up. If you can ping google's address, but you can't ping www.google.com, then your name server isn't providing the correct IP address. So the first thing to look at is what DNS server you get from your VPN. These are the possible scenarios:

  • your VPN doesn't provide a new DNS server. In that case all should work as if you had no VPN. Since this is not the case, we can exclude this scenario. This scenario doesn't make a lot of sense anyway, as once you are connected to the VPN you need a DNS server that can resolve names on the internal network you are connected to.
  • your VPN does provide a new DNS server, but it doesn't respond to your queries. There are several possible reasons for this:
    • there is a firewall in the way. In that case you cannot ping the name server.
    • the server is limited to responses from the LAN. Your VPN connection usually is provided by way of tunnels, in which case your client will have an IP address that is in a subnet not otherwise used on the LAN. In that case you cannot even resolve names of hosts on the LAN.
    • the server only provides answers for the LAN. In that case internal names are resolved just fine, but any external names are not resolved at all.

In all of the above three plausible scenarios you need to talk to your LAN system admins, to check out the problem. If you are the LAN system admin, you can use nslookup or dig to figure out which of the above is the correct scenario and then reconfigure your firewalls or DNS servers to handle it correctly.

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