On Sun, Jun 20, 2010 at 10:07 PM, green <email@example.com> wrote:
> I am working on setting up a firewall on a server/router (see
> http://wiki.debian.org/green/Router ). I have considered several different
> firewall packages, but am more comfortable just running iptables in a shell
> However, iptables scripts usually begin with a flush, and then it takes time to
> add all those rules, plus some possible interruption to traffic meanwhile.
> What about if only a small change has been made? Does iptables-restore flush
> first, or is it able to just change the rule set as necessary to match? (And
> is there a term used to describe that feature?)
in the man page of iptables-restore:
don't flush the previous contents of the table. If not
specified, iptables-restore flushes (deletes) all previous contents of
the respective IP Table.
> If iptables-restore does not support that, does anyone know of another tool
> (available the repositories) that I can use that would allow me to write a
> parseable iptables rule set?
use "diff" to show the differences between rule sets. use "iptables
-D/-A/-I" respectively to remove/add rules.