DNS cache, TTL, ARP cache

To list TTL on linux:
dig <FQ Hostname>

To list TTL on Windows:
nslookup
set debug
<FQ Hostname>

To display remaining TTL on Windows:
ipconfig /displaydns

To flush dns on windows:
ipconfig /flushdns
Windows also caches failed dns resolution for a brief period. Flushing the DNS clears these also, it can be fixed by following this post.

Linux by default doesn't have DNS cache unless nscd was installed. If nscd is installed restart it with:
sudo /etc/init.d/nscd restart

Firefox does have a DNS cache:
To clear it go to off-line mode and back to on-line mode, select and deselect: File : Work Offline.
To diable it get the DNS cache plugin or enter 'about:config' in the address bar and add a new Integer 'network.dnsCacheExpiration' with value of '0'.

Microsoft Internet Explorer (IE) also has DNS cache:
Older versions cached for 24 hours and newer versions cache for 30 minutes, see the tech article on manipulating.

To display/list ARP cache on windows, linux, and unix (hey - something in common!):
arp -a

To flush arp cache on linux:
sudo ip neigh flush all

To flush arp cache on windows:
netsh interface ip delete arpcache

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