I cant't access the switch (3560g), why?

costasanti · ‎06-04-2010

Hello,

I planned to create several VLANs and route them using our Cisco 3560G. I'm new to Cisco (sadly). When I were using the Cisco Network Assistant to manage the network, we only have one 3560g (24 port) and a couple of 2960G (8 ports). I changed the subnet of everything in the network to a non typical one (ie 192.168.201.0/24). After changing all the computers and the router, I thought I had to change the switch IP adress to the 198.168.201.254 (it was 192.168.1.254 before). After chnaging the IP of the switch, I created a couple of VLANs and assigned them to two ports (for testing purposes), the first port it was mine, and the second one it was a NAS disk. Well, after that I never managed to get into the switch again, I can't even ping it from the same subnet, I changed my cable to a different port but I can't ping or log in into the switch... what can be happening?, I'm sorry if this is a too noob question...

Does my switch remember that I was assignet to a different VLAN (he remember the MAC address of something?)

Have a nice day !

kellycpp · ‎06-05-2010

I'm relatively new to networking but isn't the address you gave for the switch on a different network than the 192.168.201.0 one? Perhaps this is a typo but it would seem that 198.168.201.0/24 is a different network and will not be able to make a connection from any of the nodes on the 192 net (not even a ping). If the switch were addressed (Vlan1) as 192.168.201.254, would this not make a connection?

My suggestion seems to be incorrect because you said you were able to access the switch to perform two additional VLAN assignments before the switch "disappeared" and this is the puzzling part. How additional VLAN assignments could disable communications with the device if the Vlan1 assignment is correct is indeed challenging.

But the switch is acting as if it were not on the network established elsewhere (192). Making an assignment and failing to save it from running-config to startup-config and rebooting would lose all the Vlan assignments and make that device unable to communicate on the 192 net.

I assume you have used the console port to access the switch (using the Cisco blue cable, of course) to check assignments using show run? Is the Vlan1 assignment correct (located near the bottom of the listing)? Of course, it is not necessary to be on any network to access the device using the console port.

K

costasanti · ‎06-05-2010

Hi Kellycpp and thanks for your answer.

Sorry it was a typo, My computer IP is 192.168.201.36, and the swith is in the 192.168.201.254. I did all that changes using the Cisco Network Assistant, but after creating the two VLANs and assign them to two ports (my own computer port and one NAS disk), I never got access again to the switch via LAN. I changed the cable to a different port but it didn't work, I can't ping thye switch again . I believe next monday I'll reset it to factory defaults...

Santi

kellycpp · ‎06-05-2010

Mr. Santi,

Well, I for one would very much like to know how several port VLAN commands can disable communications with the switch. If you physically access the switch via the Console port using a comm application on, say a laptop, you will be able to verify the Swich IP address (Vlan1) without starting from scratch. My money is on that assignment being the root of the problem.

However, admittedly, factory default would also be a quick way of readdressing the switch IP and verify it before any further vlans are set.

Hope you let me know how that turns out 'cause this is a neat problem! If it isn't the switch IP assignment, the solution will be equally neat!

Kelly