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Full Discussion: NAT Loopback and iptables
Operating Systems Linux Red Hat NAT Loopback and iptables Post 302790931 by 6765656755 on Sunday 7th of April 2013 11:18:42 AM
Old 04-07-2013
RedHat NAT Loopback and iptables
Hello, please can you help and explain me.
I have two servers. Both are RHEL6.
I use the first one like router and the second one for apache.
Router forwards 80 port on the second server and I can open that from the internet (mysite.com, for example). But I can not open mysite.com if i try to open that from the local network (Clients).
As I know i have to add NAT Loopback rules in iptables but I even have no ideas which one rules.
Please, help me ...
If it is important, i use MASQUERADE, bc my external IP is dynamic.
Now my iptables looks like that:
Code:
[root@hprouter ~]# service iptables status
Table: filter
Chain INPUT (policy ACCEPT)
num  target     prot opt source               destination         
1    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED 
2    ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0           
3    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           
4    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:22 
5    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:53 
6    ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0           state NEW udp dpt:53 
7    REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited 

Chain FORWARD (policy ACCEPT)
num  target     prot opt source               destination         
1    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED 
2    ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0           
3    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           
4    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           
5    ACCEPT     tcp  --  0.0.0.0/0            10.0.1.15           state NEW tcp dpt:80 
6    REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited 

Chain OUTPUT (policy ACCEPT)
num  target     prot opt source               destination         

Table: nat
Chain PREROUTING (policy ACCEPT)
num  target     prot opt source               destination         
1    DNAT       tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:80 to:10.0.1.15:80 

Chain POSTROUTING (policy ACCEPT)
num  target     prot opt source               destination         
1    MASQUERADE  all  --  0.0.0.0/0            0.0.0.0/0           

Chain OUTPUT (policy ACCEPT)
num  target     prot opt source               destination

NAT Loopback and iptables-10010_24png
 

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LEARN ABOUT REDHAT

ip6tables-save

IPTABLES-SAVE(8)                                                  iptables 1.6.1                                                  IPTABLES-SAVE(8)

NAME

       iptables-save -- dump iptables rules to stdout

       ip6tables-save -- dump iptables rules to stdout

SYNOPSIS

       iptables-save [-M modprobe] [-c] [-t table]

       ip6tables-save [-M modprobe] [-c] [-t table]

DESCRIPTION

       iptables-save  and ip6tables-save are used to dump the contents of IP or IPv6 Table in easily parseable format to STDOUT. Use I/O-redirect-
       ion provided by your shell to write to a file.

       -M, --modprobe modprobe_program
              Specify the path to the modprobe program. By default, iptables-save will inspect /proc/sys/kernel/modprobe  to  determine  the  exe-
              cutable's path.

       -c, --counters
              include the current values of all packet and byte counters in the output

       -t, --table tablename
              restrict output to only one table. If not specified, output includes all available tables.

BUGS

       None known as of iptables-1.2.1 release

AUTHORS

       Harald Welte <laforge@gnumonks.org>
       Rusty Russell <rusty@rustcorp.com.au>
       Andras Kis-Szabo <kisza@sch.bme.hu> contributed ip6tables-save.

SEE ALSO

       iptables-apply(8),iptables-restore(8), iptables(8)

       The  iptables-HOWTO, which details more iptables usage, the NAT-HOWTO, which details NAT, and the netfilter-hacking-HOWTO which details the
       internals.

iptables 1.6.1                                                                                                                    IPTABLES-SAVE(8)
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