How to view the DNS address assigned by DHCP?

How to view the DNS address assigned by DHCP?

ifconfig can not show it.

$ ifconfig -a
eth0      Link encap:Ethernet  HWaddr 90:e6:ba:22:6a:f2  
          inet addr:192.168.1.111  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::92e6:baff:fe22:6af2/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:224856 errors:0 dropped:0 overruns:0 frame:0
          TX packets:220040 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:166848627 (166.8 MB)  TX bytes:20256333 (20.2 MB)
          Interrupt:46 Base address:0x4000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:5889 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5889 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:468885 (468.8 KB)  TX bytes:468885 (468.8 KB)

wlan0     Link encap:Ethernet  HWaddr 00:26:5e:e8:4f:8e  
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

For at least Ubuntu 15.10 onward (possibly also earlier versions) run in a terminal:

nmcli dev show eth0 | grep IP4

eth0 is the most common iface, but it could be eth1, eth2, etc.

For older versions use nmcli dev list iface eth0 | grep IP4.

$ nm-tool 

will also list DNS Servers.

To get the DNS address open terminal (Ctrl+Alt+T) and type:

cat /var/lib/dhcp/dhclient.leases | grep dhcp-server-identifier

here it is:

cat /etc/resolv.conf

but do not edit this file

Now that Ubuntu (and Debian and almost all distros) use systemd (check with file /sbin/init) maybe the more elegant way to get this info is with:

systemd-resolve --status

• freedesktop.org docs
• Arch Wiki: Use systemd-resolve --status where it says resolvectl (systemd-resolve is a symlink to resolvectl).
• If you have problems with DNS subsystem I suggest removing resolvconf package. May conflicts with systemd-resolve.