How to access devices with static IPs on different subnet than router

networkingroutingsonicwallsubnet

I have a SonicWall TZ100, firmware SonicOS Enhanced 5.8.1.13, with a static subnet of 10.0.6.0/24 on X0. Ports X2-X4 are port shielded to X0. On ports X3 and X4 I have two devices that were moved from different locations and we forgot to update their settings while on site. Their IPs are 192.168.213.254 and 10.0.4.253. I'm not sure which one is connected to which port.

What do I have to do on the SonicWall to gain access to the web interfaces of those devices so I can change their IPs? I don't have physical access to the devices which is why I'm trying to do this remotely.

I tried assigning the X3 and X4 ports with static IPs of what the gateways for those devices should be, but it didn't help so I reverted it back. Help would be appreciated.

Best Answer

I'd approach this in a totally different way: Configure a PC (laptop) with 3 IP addresses: 192.168.213.250 and 10.0.4.250 and an address on the new subnet. connect the two devices and the laptop on the same VLAN. (no firewall, just (an isolated) hub/switch or direct connect cable) just connect to the old IP adres and start reconfiguring.

Then change your laptop back to DHCP client.

In cases where I don't even know the IP address of the network device, I connect directly with wireshark capturing with an arp filter. Most of the time, the device does an gratious arp, and then you know the IP.