I just switched to Ubuntu 14.0.4 from Windows 7 using dual boot mode. I am connecting to my office's network using wireless wlan0. I am experiencing issues when trying to ssh to access several Linux host. The hostname is not resolving to an IP. I checked /etc/resolv.conf and /etc/network/interfaces. There's no static DNS defined. I am obtaining an IP via DHCP. I have did not experience issue with Windows 7 basically.
To workaround I have to manually insert DNS and search domain in the /etc/network/interfaces file. Thereafter I am able to ssh to Linux as the hostname now translates an IP. Confirmed with nslookup.
However the problem comes when I get home on home's network. I noticed upon booting up my laptop into Ubuntu, firefox takes a while to translate a URL and noticeably slow. However once the website loads up it speed up. I did some website benchmark no issues with speed. I am highly suspecting due to DNS settings. When I comment off the DNS servers (which is my office's one), things are back to normal. My ISP indicated that no DNS is required to specify as we are assigned IPs through DHCP.
For the time being, I am doing manual comment/uncomment DNS entries to flick the switch :P Not sure if there's a better way to solve this.