Ok, been wrestling with this issue for a little bit now and can't seem to get around it. Here's my setup: I have a sonicwall firewall that is connected with a T1 through a cisco router. On our XP system's - everything works fine. I recently brought in my Windows 7 laptop and hooked it up and can't get on the internet at all. I know the problem is with our cisco router. The cisco router has interfaces for both our voice and data network. The data interface goes to the WAN port of our sonicwall and the voice goes to a small 5 port switch. The small switch has an uplink cable to both our VOIP phone system as well as to a LAN port on our sonicwall so other remote users VOIP phone works through the internet. If I unplug the voice interface ethernet cable from the 5 port switch - internet on the windows 7 laptop works fine. If I have it plugged in - no internet.
If I try to ping the sonicwall IP - it works fine. If I try to ping an internet IP it says "Reply from 172.16.0.1 - destination host unreachable" - mind you our local subnet is a 192.168.x.x so the windows 7 is able to communicate with a 172.x subnet is beyond me at this point. I have confirmed this on other Windows 7 computers - all have the same result. From the windows 7 I can also ping directly the 172.16.0.1 and it replies back. If I unplug the cisco router's voice interface, the pings time out. If I do a traceroute to 172.16.0.1 - the first hop is the sonicwall also.
I have two questions - how am I able to access the 172.x subnet from our local 192.x subnet? Secondly - what configuration error do I have in the cisco router that could be causing this?
If I try to ping the sonicwall IP - it works fine. If I try to ping an internet IP it says "Reply from 172.16.0.1 - destination host unreachable" - mind you our local subnet is a 192.168.x.x so the windows 7 is able to communicate with a 172.x subnet is beyond me at this point. I have confirmed this on other Windows 7 computers - all have the same result. From the windows 7 I can also ping directly the 172.16.0.1 and it replies back. If I unplug the cisco router's voice interface, the pings time out. If I do a traceroute to 172.16.0.1 - the first hop is the sonicwall also.
I have two questions - how am I able to access the 172.x subnet from our local 192.x subnet? Secondly - what configuration error do I have in the cisco router that could be causing this?
