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Top Forums UNIX for Advanced & Expert Users How iptables directs to localhost in this series of iptable rules Post 302565572 by otheus on Tuesday 18th of October 2011 08:26:58 AM
Old 10-18-2011
I probably could answer most of your questions, but what you really ought to do is simply read the iptables man pages. It has most of the answers you seek. For instance, concerning ESTABLISHED versus RELATED, it states:
Code:
   state
       This module, when combined with connection tracking, allows access to the connection tracking state for this packet.

       [!] --state state
              Where state is a comma separated list of the connection states to match.  Possible states are INVALID meaning that the packet could not be identi-
              fied for some reason which includes running out of memory and ICMP errors which don't correspond to any known connection, ESTABLISHED meaning that
              the packet is associated with a connection which has seen packets in both directions, NEW meaning that the packet has started a new connection, or
              otherwise  associated  with a connection which has not seen packets in both directions, and RELATED meaning that the packet is starting a new con-
              nection, but is associated with an existing connection, such as an FTP data transfer, or an ICMP error.

 

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IPTABLES-APPLY(8)						  iptables 1.6.1						 IPTABLES-APPLY(8)

NAME
iptables-apply - a safer way to update iptables remotely SYNOPSIS
iptables-apply [-hV] [-t timeout] [-w savefile] {[rulesfile]|-c [runcmd]} DESCRIPTION
iptables-apply will try to apply a new rulesfile (as output by iptables-save, read by iptables-restore) or run a command to configure iptables and then prompt the user whether the changes are okay. If the new iptables rules cut the existing connection, the user will not be able to answer affirmatively. In this case, the script rolls back to the previous working iptables rules after the timeout expires. Successfully applied rules can also be written to savefile and later used to roll back to this state. This can be used to implement a store last good configuration mechanism when experimenting with an iptables setup script: iptables-apply -w /etc/network/iptables.up.rules -c /etc/network/iptables.up.run When called as ip6tables-apply, the script will use ip6tables-save/-restore and IPv6 default values instead. Default value for rulesfile is '/etc/network/iptables.up.rules'. OPTIONS
-t seconds, --timeout seconds Sets the timeout in seconds after which the script will roll back to the previous ruleset (default: 10). -w savefile, --write savefile Specify the savefile where successfully applied rules will be written to (default if empty string is given: /etc/network/iptables.up.rules). -c runcmd, --command runcmd Run command runcmd to configure iptables instead of applying a rulesfile (default: /etc/network/iptables.up.run). -h, --help Display usage information. -V, --version Display version information. SEE ALSO
iptables-restore(8), iptables-save(8), iptables(8). LEGALESE
Original iptables-apply - Copyright 2006 Martin F. Krafft <madduck@madduck.net>. Version 1.1 - Copyright 2010 GW <gw.2010@tnode.com or http://gw.tnode.com/>. This manual page was written by Martin F. Krafft <madduck@madduck.net> and extended by GW <gw.2010@tnode.com or http://gw.tnode.com/>. Permission is granted to copy, distribute and/or modify this document under the terms of the Artistic License 2.0. iptables 1.6.1 IPTABLES-APPLY(8)
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