How can I remove specific rules from iptables

Question

I am hosting special HTTP and HTTPS services on the ports 8006 and 8007 respectively  I use iptables to  activate  the server  i e  to route the incoming HTTP and HTTPS ports   iptables -A INPUT -i eth0 -p tcp --dport 80 -j ACCEPT iptables -A INPUT -i eth0 -p tcp --dport 443 -j ACCEPT iptables -A INPUT -i eth0 -p tcp --dport 8006 -j ACCEPT iptables -A INPUT -i eth0 -p tcp --dport 8007 -j ACCEPT iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 8006  iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 443 -j REDIRECT --to-port 8007   iptables -A OUTPUT -t nat -d 127 0 0 1 -p tcp --dport 80 -j REDIRECT --to-ports 8006 iptables -A OUTPUT -t nat -d 127 0 0 1 -p tcp --dport 443 -j REDIRECT --to-ports 8007    This works like a charm  However I would like to create another script that disables my server again  i e  restore iptables to the state it was in before running the lines above  However I am having a hard time figuring out the syntax to remove these rules  The only thing that seems to work is a complete flush   iptables -F iptables -X iptables -t nat -F iptables -t nat -X iptables -t mangle -F iptables -t mangle -X iptables -P INPUT ACCEPT iptables -P FORWARD ACCEPT iptables -P OUTPUT ACCEPT   But that will also delete other iptables rules which is undesired

User · Accepted Answer

Execute the same commands but replace the  -A  with  -D   For example   iptables -A       becomes  iptables -D

User · Answer

First list all iptables rules with this command   iptables -S   it lists like   -A XYZ -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT   Then copy the desired line  and just replace -A with -D to delete that   iptables -D XYZ -p

User · Answer

Use -D command  this is how man page explains it   -D  --delete chain rule-specification -D  --delete chain rulenum     Delete  one  or more rules from the selected chain        There are two versions of this command       the rule can be specified as a number in the chain  starting at 1 for the first rule  or a rule to match    Do realize this command  like all other command -A  -I  works on certain table  If you are not working on the default table filter table   use -t TABLENAME to specify that target table   Delete a rule to match  iptables -D INPUT -i eth0 -p tcp --dport 443 -j ACCEPT   Note  This only deletes the first rule matched  If you have many rules matched this can happen in iptables   run this several times   Delete a rule specified as a number  iptables -D INPUT 2   Other than counting the number you can list the line-number with --line-number parameter  for example   iptables -t nat -nL --line-number

User · Answer

You can also use the following syntax  iptables -D  lt chain name gt   lt rule number gt   For example Chain HTTPS      target     prot opt source               destination     ACCEPT     all  --  anywhere             anywhere     ACCEPT     all  --  10 0 0 0 8           anywhere     ACCEPT     all  --  182 162 0 0 16       anywhere  To delete the rule  ACCEPT     all  --  10 0 0 0 8           anywhere  iptables -D HTTPS 2

User · Answer

Assume that  if you want to remove NAT rules   List the appended IPtables using the command below     sudo iptables -L -t nat -v  Chain PREROUTING  policy ACCEPT 18 packets  1382 bytes   pkts bytes target     prot opt in     out     source               destination              7   420 DNAT       tcp  --  any    any     anywhere             saltmaster           tcp dpt http to 172 31 5 207 80     0     0 DNAT       tcp  --  eth0   any     anywhere             anywhere             tcp dpt http to 172 31 5 207 8080   If you would like to remove the nat rule from the IPtables  just execute the command     sudo iptables -F -t nat -v  Flushing chain  PREROUTING  Flushing chain  INPUT  Flushing chain  OUTPUT  Flushing chain  POSTROUTING    Then  you can verify that     sudo iptables -L -t nat -v

User · Answer

The best solution that works for me without any problems looks this way  1  Add temporary rule with some comment   comment   cat  proc sys kernel random uuid   sed  s  -  g   iptables -A       -m comment --comment    comment   -j REQUIRED ACTION   2  When the rule added and you wish to remove it  or everything with this comment   do   iptables-save   grep -v    comment     iptables-restore   So  you ll 100  delete all rules that match the  comment and leave other lines untouched  This solution works for last 2 months with about 100 changes of rules per day - no issues Hope  it helps

User · Answer

You may also use the rule s number  --line-numbers    iptables -L INPUT --line-numbers   Example output    Chain INPUT  policy ACCEPT       num  target prot opt source destination     1    ACCEPT     udp  --  anywhere  anywhere             udp dpt domain      2    ACCEPT     tcp  --  anywhere  anywhere             tcp dpt domain      3    ACCEPT     udp  --  anywhere  anywhere             udp dpt bootps      4    ACCEPT     tcp  --  anywhere  anywhere             tcp dpt bootps   So if you would like to delete second rule    iptables -D INPUT 2   Update  If you use d  a specific table  eg nat   you have to add it to the delete command  thx to  ThorSummoner for the comment   sudo iptables -t nat -D PREROUTING 1

[linux] How can I remove specific rules from iptables?

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