DNS failure on one workstation

Question

I have one workstation on my home network that is having sporadic issues and timeouts with DNS resolution. It came out of nowhere (worked fine last week).

The network setup is as follows :

Network address 192.168.50.0/24 Default GW : 192.168.50.254. ISP provided all-in-one router (does DSL, DHCP, DNS and more), but only routing is enabled. - DHCP/DNS : 192.168.50.1 Ubuntu 12.04.4 LTS server with bind9 and dhcpd.

DHCP config :

root@server:~# cat /etc/dhcp/dhcpd.conf 
authoritative;

# domain.com is an existing domain that I own
option domain-name "home.domain.com";
option domain-name-servers 192.168.50.1;
option netbios-name-servers 192.168.50.1; 

ddns-updates        on;
ddns-update-style   interim;
ignore          client-updates;
update-static-leases    on;

default-lease-time  600;
max-lease-time      7200;
log-facility        local7;

include "/etc/dhcp/home_rndc.key";
# content of home_rdnc.key :
# key "rndc-key" {
#    algorithm hmac-md5;
#    secret "...";
# };

zone home.domain.com. {
    primary 127.0.0.1;
    key "rndc-key";
}

zone 50.168.192.in-addr.arpa. {
    primary 127.0.0.1;
    key "rndc-key";
}

subnet 192.168.50.0 netmask 255.255.255.0 {
    range 192.168.50.50 192.168.50.150;
    option routers 192.168.50.254;

    host ZOTAC {
        hardware ethernet aa:bb:cc:dd:ee:ff;
        fixed-address 192.168.50.10;
    }
}

The setup works like a charm on all connected devices regardless of OS (Android, Linux, and even Win8), except for one Ubuntu 14.04 LTS box (the one with the static IP assignment actually).

All connectivity is fine, but DNS resolution within Chrome/Firefox just idles/times-out at random, and when it does work, it is really slow. I have tried disabling dns-masq without success.

Even manually setting DNS' does not change a thing (tried various external DNS providers without any success).

I'm probably missing something, but I don't know what, and I'd really like to avoid re-installing that machine.

Answer 1

Well, I finally got it worked out :

I had changed the order of name resolution providers in nssswitch.conf, and it was performing WINS lookups before DNS.

I changed :

hosts:          files myhostname mdns4_minimal [NOTFOUND=return] wins dns mdns4

To

hosts:          files myhostname mdns4_minimal [NOTFOUND=return] dns mdns4 wins 

And my DNS resolution is back to normal. What strikes me is that this config worked perfectly fine before, but at least my issue is solved.