[TriLUG] [Off Topic] Zyxel DSL router giving DHCP address to Cisco ASA when in bridged mode

[Chris Bullock]

I just installed a Cisco ASA 5505 at my house tonight, and couldn't get it to work.  After looking a little deeper it was getting a 10.0.0.2 address on the WAN interface.  I telnet'ed to the default gateway and it was my ZyXel DSL modem.  Looking, I verified that it had only bridging turned on for the DSL modem, however it was giving out DHCP on the LAN side, only way to get my Internet working was to change it to routed.  I power cycled the modem, wondering if for some reason my ISP didn't know how to handle multiple mac addresses after I swapped the gear, but the modem still dished out DHCP.

If I take my Belkin or Linksys routers, the belkin and Linksys get a public IP address for the WAN.

Not sure where to go next.
Chris