Routing issues

[julienf28]

we have a PVN and it is segmented by Vlans. One of our Laptop users had an IP address. I.E. 10.51.42.100 and the gateway was 10.51.40.1. Wen we would do a tracert to outside our 10.51 environement it would hit the 10.51.164.1 gateway (which is wireless)

I looked at the DHCP scope and her Laptop wasn't on that 10.51.165.X network plus I did an Ip release / renew and got the same IP address as before (10.51.42.100) and now we are able to hit the proper gateway which would be 10.51.40.1.

This is a very odd problem but I'm looking more for a possible cause of this problem as everything seems to be working fine.

Verified the switching port and it has the proper vlan (not wieless vlan) and verified the DHCP servers which didn't list her laptop in the scopes. Also her wireless was disable which adds more to the confusion.

Any ideas would be apreciated.

[ohassairi · Accepted solution]

when problem occurs use the command "route print" under c:\> to see if there is a new introduced route in your table that points to 10.51.164.1.

some ICMP messages (like redirect) can change the gateway of your PC.

some routing protocols can do that also. insure you are not accepting any dynamic routing protocol (RIP, OSPF,...) in your NIC .

please copy and paste the output of "route print" when the prolem occurs again.