Cisco – Using Cisco ASDM to change internal IP address of 5505

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I'm trying to set up a new 5505 for the first time. I am not a network admin, so I'm using the graphical tool that comes with it, ASDM. One of the things I am trying to do is change the subnet used by the "internal" network to 10.0.0.x. In the startup wizard, I change:

  • the internal interface's ip address to 10.0.0.1
  • the dhcp server to serve ip addresses in 10.0.0.10-40
  • allow incoming https/ASDM connections on internal's 10.0.0.x subnet

Then when I click "go" at the end of the wizard, a modal dialog pops up that says "sending command(s) to router" or somesuch. That dialog never goes away. Further, it seems like the configuration never gets applied. I can't renew the DHCP lease on the machine connected to the router.

To be clear, the machine is connected over ethernet on the interface that I'm trying to change, but it seems like ASDM could/should be smart enough to handle that. Does it not?

Edit: In response to @Alex questions below. When I start out, my machine has IP 192.168.1.5, and the inside interface of the ASA has 192.168.1.1. When I work through the wizard, I am setting the inside interface of the ASA to 10.0.0.1, and setting up a DHCP address pool of 10.0.0.10-40. However I don't ever seem to be able to get an IP address from DHCP for my machine in the 10.x subnet.

Best Answer

I typically kill the internal DHCP server on the ASA when I do this. The issue is that the DHCP server's pool belongs to the default 192.168.x.x subnet that the ASA comes from the factory with. This discrepancy is what causes the startup wizard to fail.

You can unconfigure the DHCP service and try again.

I usually give myself telnet access to the ASA in the GUI... and work from there.

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