В винде,в адресной строке прописал 192.168.1.1 и зашёл в настройки модема.
dima@dima-home ~ $ sudo dhclient eth0
[sudo] password for dima:
Internet Systems Consortium DHCP Client V3.1.3
Copyright 2004-2009 Internet Systems Consortium.
All rights reserved.
For info, please visit
https://www.isc.org/software/dhcp/Listening on LPF/eth0/00:22:15:e1:66:4d
Sending on LPF/eth0/00:22:15:e1:66:4d
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3
DHCPOFFER of 192.168.1.2 from 192.168.1.1
DHCPREQUEST of 192.168.1.2 on eth0 to 255.255.255.255 port 67
DHCPACK of 192.168.1.2 from 192.168.1.1
bound to 192.168.1.2 -- renewal in 38249 seconds.