Renovar ip en Ubuntu

Si no se le pasa argumento alguno al comando dhclient, este configurará todas las interfaces de red que se encuentre.

$ sudo dhclient -v

Internet Systems Consortium DHCP Client 4.3.5
Copyright 2004-2016 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
 
Listening on LPF/ens33/00:0c:29:04:6e:18
Sending on   LPF/ens33/00:0c:29:04:6e:18
Sending on   Socket/fallback
DHCPDISCOVER on ens33 to 255.255.255.255 port 67 interval 5
DHCPREQUEST of 192.168.170.136 on ens33 to 255.255.255.255 port 67
DHCPOFFER of 192.168.170.136 from 192.168.170.254
DHCPACK of 192.168.170.136 from 192.168.170.254
bound to 192.168.170.136 -- renewal in 867 seconds.