Invalid IP configured in Enterasys VH-2402S

[Dale]

I have acquired an Enterasys VH-2402S switch. I am unable to communicate with it using console management port via puTTy (black screen/no response) or any other method. I had no idea of the IP configured in this switch. After some thought, since I acquired this switch from a network guy, who also did not know the IP, suggested I try a range of IPs in the 172.22.xx.xx range since it came from his company. Using AdvanceIP Scanner I was able to determine the configured IP address of the switch is 172.22.xx.255. Wow. This is an invalid IP I'm sure, and is preventing me access to it via CLI / ethernet cable. How do I gain access to this switch? I asked that network guy and just got a shrug and statement that I probably can't. It's almost like he knew it and wasn't bothering with it... Anyway, any ideas on how I can get access to this switch to change the IP to make the switch useful? Thnks!

[Dale]

I'm just starting on this again today. Actually, I have searched high and low; googled, Binged, looked at manuals, etc to see if there was a way to reset to factory default. Since Enterasys is now Extreme Networks most web links point to it's website and knowledge base where I found nothing concerning resetting the switch. I would love to reset!

[Dale]

I'll be back with this more and respond with some results on 8/29. Thanks all. It really is appreciated! /dale

[Dale]

Perhaps, there really is something wrong with the switch? The supposed configuration was 172.22.34.13 / 255.255.254.0 /172.22.34.9 (.9 being the gateway). After badgering the guy I got this from he says his only knowledge of the switch was the above recorded config he had in his files but he says it was misconfigured (he didn't know to what). When I mentioned the .255 I found thru AdvancedIP scanner, he said maybe... I'm not sure I'm getting straight answers from him, but regardless it would be useful to me if I could make this switch work. Thanks all for taking an interest in this problem. I'm going to try the wireshark thin now...

[Robert_Cummins]

Yes, if the network is 172.22.34.0/23 then the broadcast is 172.22.35.255 and that's a problem as the switch is at the broadcast address of the network. Typical tools like ssh and telnet are not going to work w/ a broadcast address....but... you can fool them! If you're isolated here, set the net mask on your system to a /21 and pick an address in the 172.22.32.0/22 range (actually, you need to assign the address on the same network as the target system, based on what its network and mask are. You need this connection to be switched and not routed otherwise it won't work. I'd pick 172.22.35.254/21; the network needs to be large enough that 172.22.35.255 is not the broadcast address for the network; 172.22.32.0/22 has a broadcast 172.22.35.255; 172.22.32.0/21 has a broadcast of 172.22.63.255). You'll need to modify your network connection before using nmap as I don't think nmap works with a broadcast address; at least I've never tried it.

[Robert_Cummins]

I think I'm off on the broadcast for 172.22.32.0/21; it's 2^11 host IPs and the network changes every 2^3 or 8; so the next network is 172.22.40.0/21 and the broadcast would have been 39.255; apologies for the math mistake.

The idea is to make the target address on the same IP network as your device and not a broadcast address. If it is on the same IP network then the connection is switched instead of routed. Switches do not care about IP addresses, they only care about MAC addresses. I've used this technique many times to "recover" a machine w/ the wrong IP address for the VLAN to which it is attached though I've never had to try it with a broadcast address; most sane OSes will not allow you to assign a broadcast address to an interface.

If the switch thinks its address is the broadcast address it may not respond to the ARP request for 172.22.35.255; if that's the case you'll have to populate your ARP table with the IP address/MAC address of the switch and it still may not work but it's something to try.