Logging iptables to a Separate File on Centos

Here i will show you how to make iptables log to a separate file on centos.

First i will create a folder for iptables log

        [root@test]# mkdir /var/log/iptables/

Now i need to  create a file "/etc/rsyslog.d/iptables.conf " and give it a little content

        [root@test]# vim /etc/rsyslog.d/iptables.conf

            :msg, startswith, "iptables: " -/var/log/iptables/iptables.log
            &~

Open your rsyslog.conf file and modify below things

        [root@test]# vim /etc/rsyslog.conf

           # Don't log private authentication messages!
           *.info;mail.none;authpriv.none;cron.none;kern.none       /var/log/messages


          # iptables log
           kern.*                            /var/log/iptables/iptables.log


use below command to restart the rsyslog

[root@test]# service rsyslog restart
Shutting down system logger:                               [  OK  ]
Starting system logger:                                    [  OK  ]
[root@test]# 

Now you can see all the iptables message logged to a separate file "iptables.log"

 [root@test]# tailf /var/log/iptables/iptables.log

Feb 09 23:39:46 test kernel: iptables_InvalidDrop IN=eth0 OUT= MAC=38:60:77:ef:df:d8:00:26:88:75:e7:84:08:00 SRC=83.243.58.157 DST=192.168.1.100 LEN=40 TOS=0x00 PREC=0x00 TTL=56 ID=0 DF PROTO=TCP SPT=57543 DPT=80 WINDOW=0 RES=0x00 RST URGP=0
 
Feb 09 23:39:46 test kernel: iptables_InvalidDrop IN=eth0 OUT= MAC=38:60:77:ef:df:d8:00:26:88:75:e7:84:08:00 SRC=83.243.58.157 DST=192.168.1.100 LEN=40 TOS=0x00 PREC=0x00 TTL=56 ID=0 DF PROTO=TCP SPT=57543 DPT=80 WINDOW=0 RES=0x00 RST URGP=0
 
Feb 09 23:39:46 test kernel: iptables_InvalidDrop IN=eth0 OUT= MAC=38:60:77:ef:df:d8:00:26:88:75:e7:84:08:00 SRC=83.243.58.157 DST=192.168.1.100 LEN=40 TOS=0x00 PREC=0x00 TTL=56 ID=0 DF PROTO=TCP SPT=57543 DPT=80 WINDOW=0 RES=0x00 RST URGP=0
 
Feb 09 23:39:46 test kernel: iptables_InvalidDrop IN=eth0 OUT= MAC=38:60:77:ef:df:d8:00:26:88:75:e7:84:08:00 SRC=83.243.58.157 DST=192.168.1.100 LEN=40 TOS=0x00 PREC=0x00 TTL=56 ID=0 DF PROTO=TCP SPT=57543 DPT=80 WINDOW=0 RES=0x00 RST URGP=0
 
Feb 09 23:39:46 test kernel: iptables_InvalidDrop IN=eth0 OUT= MAC=38:60:77:ef:df:d8:00:26:88:75:e7:84:08:00 SRC=83.243.58.157 DST=192.168.1.100 LEN=40 TOS=0x00 PREC=0x00 TTL=56 ID=0 DF PROTO=TCP SPT=57543 DPT=80 WINDOW=0 RES=0x00 RST URGP=0