Hola amigos, he estado mirando en /var/log/messages y esto sale:
Nov 14 13:50:19 dns1 dhclient[1143]: bound to 99.121.xxx.xxx -- renewal in 299 seconds. Nov 14 13:50:31 dns1 dhcpd: DHCPREQUEST for 172.16.1.2 from c8:0a:a9:xx:xx:xx (aquarium) via eth1 Nov 14 13:50:31 dns1 dhcpd: DHCPACK on 172.16.1.2 to c8:0a:a9:xx:xx:xx (aquarium) via eth1 Nov 14 13:55:18 dns1 dhclient[1143]: DHCPREQUEST on eth0 to 192.168.1.254 port 67 (xid=0x5d50d7a) Nov 14 13:55:18 dns1 dhclient[1143]: DHCPACK from 99.121.xxx.xxx (xid=0x5d50d7a) Nov 14 13:55:19 dns1 dhclient[1143]: bound to 99.121.xxx.xxx -- renewal in 252 seconds.
Esta salida del dhcp es normal.
Gracias de antemano