DNS Flush

When your surfing the web your system caches the location of all websites it comes across by saving the IP address and domain name. For example:

10.10.10.10 www.example.com

While is great for reducing overhead by skipping the DNS lookup; problems arise when the website changes it's IP. If your ever having trouble getting to a website you know is there, you can always try running one of these commands to flush the DNS cache.

Windows

ipconfig /flushdns

MAC OSX <= 10.4

lookupd -flushcache

MAC OSX >= 10.4

dscacheutil -flushcache

Ubuntu

sudo /etc/init.d/dns-clean start

Misc Linux

/etc/init.d/nscd restart

service nscd restart