Cannot Access WRT54GL Config Page

Question

I am doing some consulting work for a small business and cannot gain access to the routers configuration page.  Here is a summary of the environment:
* WRT54GL, ver. 1.1.
* The WAN port of the router is connected directly to the Verizon DSL modem for Internet access.
* Port 1 is connected to the main switch (192.168.102.x subnet).
* Users can also connect to this router by wireless (192.168.3.x subnet).
* When I connect to the wireless network, it appears that the router has been assigned an IP address of 192.168.3.1.  When I execute an ipconfig command:
Connection-specific DNS suffix:   lan
Dhcp Enabled:                                 Yes
Autoconfiguration Enabled:           Yes
IP Address:                                       192.168.3.240
Subnet Mask:                                    255.255.255.0
Default Gateway:                              192.168.3.1
DHCP Server:                                   192.168.3.1
DNS Server:                                      192.168.3.1
* When I connect to the "wired" network, it appears that the router has been assigned an IP address of 192.168.102.254.  When I execute an ipconfig command:
Connection-specific DNS suffix:   ourcompany.com
Dhcp Enabled:                                 Yes
Autoconfiguration Enabled:           Yes
IP Address:                                       192.168.102.111
Subnet Mask:                                    255.255.255.0
Default Gateway:                              192.168.102.254
DHCP Server:                                   192.168.102.15
DNS Server:                                      192.168.102.254
* When I am on the wireless network, I can successfully ping 192.168.3.1 and 192.168.1.1.  When I ping 192.168.102.254, it resolves to 192.168.3.1 and returns a "Destination port unreachable".
* When I connect to the "wired" network, I can succesfully ping 192.168.3.1 (as well as 192.168.102.254 - obviously), but I cannot ping 192.168.1.1 ("Request timed out").
ACTIONS:
1)  I am trying to connect to the WRT54GL device to examine the configuration and create a route between the two networks.  I have downloaded Linksys Easylink Advisor and I can see the network (on both connections), but cannot get into the configuration pages  I receive an error ("MSG_100_000_000 Unhandled error ...") and then goes into an endless loop "Retrieving Router Settings".
2)  When I attempt to access through a web browser (from both subnets), I get a "page not found" error.
3)  I connected a cable directly to an open port in the router.  I immediately had Internet access and was assigned an IP in the 192.168.3.x subnet.  Still I could not connect to the administration page on either 192.168.3.1 or 192.168.1.1.
4)  Power cycled the router and re-attempted 1,2, and 3 above - same result.
5)  Downloaded the latest firmware upgrade and tried to apply through linksys-ftp (while connected directly to the router).  In the dialogue box I entered 192.168.1.1 and the default password of 'admin' and pointed to the firmware upgrade file.  After clicking the "Upgrade" button and three tries, I get an "Unable to get responses from server" message.  This also happens when trying to connect to 192.168.1.1.
6)  Since I am not sure whether I should be connecting to 192.168.3.1 or 192.168.1.1, I also tried to assign a static IP on my laptop in the 192.168.1.x subnet, but that left me with no network connection at all.
SO .... where do I go from here?  I know I can do a reset and get back to the factory installed settings on the router, but I really prefer NOT to do that.  Whoever set this up is long gone, and no one here has any idea about the network or even who it was that set it up.  I think it would take a long time to reconstruct things (during off hours since people need to be connected to the network all day), so I don't want to go down that path.
Any help or insights would be greatly appreciated.
Thanks,
Tom

Answer 1

What is the model of the switch that you are using? Is this just a plain pass through switch or a manageable one? I am curious where you are getting that 192.168.102.x ip range. If wired to the router you are getting 192.168.3.1, then that should be the address that you use when you run the tftp utility. And also what is the ip address that you are getting from the modem? Is the modem bridged or is it functioning as a modem/router?
If you want to upgrade the router's firmware, I suggest that you remove the switch and the modem from the loop and see if you can access the router interface. If you cannot, then reset the router for 30 seconds, powercycle it and see if you can now access the router interface.