Linux IPTables: How to Add Firewall Rules (With Allow SSH Example)
Feb 16, 2011, 23:33 (0 Talkback[s])
Re-Imagining Linux Platforms to Meet the Needs of Cloud Service Providers
"This article explains how to add iptables firewall rules using
the "iptables -A" (append) command.
""-A" is for append. If it makes it easier for you to remember
"-A" as add-rule (instead of append-rule), it is OK. But, keep in
mind that "-A" adds the rule at the end of the chain.
"Again, it is very important to remember that -A adds the rule
at the end.
"Typically the last rule will be to drop all packets. If you
already have a rule to drop all packets, and if you try to use "-A"
from the command-line to create new rule, you will end-up adding
the new rule after the current "drop all packets" rule, which will
make your new rule pretty much useless."