I've got a Cisco router doing ADSL with zone based firewall running. I'm going to switch to NBN VDSL soon, and intend to stick a bridged modem on a spare FastEthernet port, put said port into the internet zone, set the interface to use DHCP (the ISP we're looking at uses DHCP) and all the usual magic. My problems come when I then want to monitor the modem. Basically I need to have DHCP for the internet, but need a second static address to route to the modem. Obvious first idea was "ip address dhcp" and "ip address <details> secondary" on the port I'm going to use. But Cisco apparently don't see the point of that, and disable the secondary address when you enable DHCP. Second idea was VLANs. But the modem doesn't support VLANs on the LAN side. Any ideas?