ip alias on wan

Hi guys!
i have modem with ip 192.168.1.1. it connected to wan port of ac68u. lan ip of ac68u 10.0.0.1, wan - dinamyc from isp.
i ssh to ac68u:

ip add list dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether e0:3f:49:23:9d:a0 brd ff:ff:ff:ff:ff:ff
inet 46.201.151.176/23 brd 46.201.151.255 scope global eth0
inet 192.168.1.5/24 scope global eth0
inet6 fe80::e23f:49ff:fe23:9da0/64 scope link
valid_lft forever...

ip alias on wan