 REJECT.  DROP,       .

--reject-with 

      .  
,    ICMP (. ): icmp-net-
unreachable, icmp-host-unreachable, icmp-port-unreachable,icmp-proto-unreachable,
icmp-netprohibited  icmp-host-prohibited.    echo-reply  -
, ,  ping- ICMP   ping-.  -
  tcp-reset  ,    INPUT    ,
  TCP- RST.    INPUT, FORWARD  OUTPUT
    ,    .

 RETURN.         
.

 SNAT. Source Network Address Translation (   ).
   .     , -
    Internet.

--to-source ip[-ip][:-]

 IP-          
   IP.   ,   . -
   ,     
 .     POSTROUTING  NAT.
   IP- (ip-ip)    
to-source  iptables    ,    
   .

     TCP  UDP (-p tcp  - udp),  
 .     ,    -
.      NAT     IP-
  .       NAT   
   ,        ().  
  512        512, 
 512  1024      512  1024,    
 1024        1024.

      

 iptables-save        
,       .  iptables-restore  
  iptables-save     .    
  iptables-save.

# iptables-save

# Generated by iptables-save vl.2.8 on Sun Mar 14 20:41:37 2004
( iptables-save vl.2.8  Be 14 Map 2004 20:41:37)

*filter

:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]

 25. iptables:                                          769