TG582n listening on 192.168.1.254 & .253

[#1]

I'm a new customer with the TG582n router.  I noticed today that is is listening on both 192.168.1.254 and 192.168.1.253.  Both IP addresses are associated with the MAC address of the router.  The router's admin interface (HTTP & telnet) however are only listening on .254, but .253 does respond to pings.
The router seems to have two DHCP pools:
DHCP Pool Name Address Range Gateway
LAN_private 192.168.1.64 - 192.168.1.252 192.168.1.254
LAN_VIRT 192.168.1.253 - 192.168.1.253 192.168.1.254
What's the LAN_VIRT pool for?

[#2]

It's the usb port (shared on a cifs network)