CSF dropping connections
Posted: 10 Sep 2016, 16:52
Hello,
We are unable to reach the websites on the server when csf is enabled. Upon checking, the ip is not blocked as per lfd.log. However "/var/log/messages" has full of similar messages as below:.
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Sep 10 05:14:59 eeg kernel: [2144786.604936] Firewall: *TCP_IN Blocked* IN=eth0 OUT= MAC=fa:16:3e:a8:d8:45:00:1c:73:57:7f:c5:08:00 SRC=185.81.xxx.xxx DST=yyy.yyy.23.46 LEN=60 TOS=0x08 PREC=0x20 TTL=47 ID=36972 DF PROTO=TCP SPT=58396 DPT=80 WINDOW=5840 RES=0x00 SYN URGP=0
Sep 10 05:15:03 eeg kernel: [2144790.948329] Firewall: *TCP_IN Blocked* IN=eth0 OUT= MAC=fa:16:3e:a8:d8:45:00:1c:73:57:7b:97:08:00 SRC=185.81.xxx.xxx DST=yyy.yyy.23.46 LEN=60 TOS=0x08 PREC=0x20 TTL=47 ID=61953 DF PROTO=TCP SPT=40971 DPT=80 WINDOW=5840 RES=0x00 SYN URGP=0
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As you can see, for some reasons, the incoming connections are being dropped. If I disable the csf firewall, the problem stops.
OS: CentOS release 6.8
cPanel: 11.58.0.27
I am not sure what parameter to tweak. Both connection tracker and synflood is disabled.
Any suggestions is appreciated.
Abdul.
We are unable to reach the websites on the server when csf is enabled. Upon checking, the ip is not blocked as per lfd.log. However "/var/log/messages" has full of similar messages as below:.
--------------------------------------------------
Sep 10 05:14:59 eeg kernel: [2144786.604936] Firewall: *TCP_IN Blocked* IN=eth0 OUT= MAC=fa:16:3e:a8:d8:45:00:1c:73:57:7f:c5:08:00 SRC=185.81.xxx.xxx DST=yyy.yyy.23.46 LEN=60 TOS=0x08 PREC=0x20 TTL=47 ID=36972 DF PROTO=TCP SPT=58396 DPT=80 WINDOW=5840 RES=0x00 SYN URGP=0
Sep 10 05:15:03 eeg kernel: [2144790.948329] Firewall: *TCP_IN Blocked* IN=eth0 OUT= MAC=fa:16:3e:a8:d8:45:00:1c:73:57:7b:97:08:00 SRC=185.81.xxx.xxx DST=yyy.yyy.23.46 LEN=60 TOS=0x08 PREC=0x20 TTL=47 ID=61953 DF PROTO=TCP SPT=40971 DPT=80 WINDOW=5840 RES=0x00 SYN URGP=0
-------------------------------------------------
As you can see, for some reasons, the incoming connections are being dropped. If I disable the csf firewall, the problem stops.
OS: CentOS release 6.8
cPanel: 11.58.0.27
I am not sure what parameter to tweak. Both connection tracker and synflood is disabled.
Any suggestions is appreciated.
Abdul.