countermeasures - Developer IT

Hacking prevention, forensics, auditing and counter measures.

- by tmow

Recently (but it is also a recurrent question) we saw 3 interesting threads about hacking and security: My server's been hacked EMERGENCY. Finding how a hacked server was hacked File permissions question The last one isn't directly related, but it highlights how easy it is to mess up with a web server administration. As there are several things, that can be done, before something bad happens, I'd like to have your suggestions in terms of good practices to limit backside effects of an attack and how to react in the sad case will happen. It's not just a matter of securing the server and the code but also of auditing, logging and counter measures. Do you have any good practices list or do you prefer to rely on software or on experts that continuously analyze your web server(s) (or nothing at all)? If yes, can you share your list and your ideas/opinions?

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Engineers are using explosives to remove hard rock outside our office building. What countermeasures should we take?

- by Karrax

Our building is located approx. 100 meters from the explosive charges. They happen several times per day, and really shake the entire building a lot. This is going to go on for many days and the blasts are supposed to get stronger. Our server rooms are nothing fancy; one of them has all the racks on hard concrete while the other one has a raised floor (the one which allows the cables to go beneath it). Does anyone have any tips, countermeasures or best practices for us? Currently we are thinking of the following countermeasures: Daily report of the server rooms status lights (HD lights, power supplies and so on). Nightly check disk scan on the most important servers Order in extra supply of spare harddrives Edit: Many good answers here! However one needs to be accepted. The highest voted answer at the time of this edit will get their answer accepted.

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Free forum engine with good anti-attack mechanisms

- by macias

I am looking for forum engine (for discussions) with good attack countermeasures built in. Windows (preferrably) or Linux. Free (as beer). I think about registration flooding and blocking user accounts attacks. For registration, such engine should have at least: captcha blocking mulitple registrations from the same IP providing login (for logging in) and user name (for displaying the author of the posts) For logging in: no blocking on multiple tries -- instead after X try sending via mail a token, the third piece needed for next login -- without it logging in will be impossible (it would be similar to activation process) The engine should be designed with two ideas in mind: protecting engine against attacks 0 penalty for decent users Thank you in advance for your help and recommendations.

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Lots of spambot registrations on PHPBB forum

- by Dreamdealer

We have a PHPBB forum running for a few years with admin approval of newly registred users. New users can not post on the forum untill we approve their new account. So I get an e-mail for every new registration, and sometimes there are spambot registrations amongst them. But untill yesterday this was only a few a year, but overnight I got 32 (!) new registrations and they keep rolling in every 15 minutes or so. I run the latest PHPBB version and spambot countermeasures are on. We first had the ReCaptcha option, but that didn't work well. Then we changed it to a Q&A version and that worked. I changed the question an hour ago, but the new spam registrations keep happening, whatever I do. Help!

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iptables syn flood countermeasure

- by Penegal

I'm trying to adjust my iptables firewall to increase the security of my server, and I found something a bit problematic here : I have to set INPUT policy to ACCEPT and, in addition, to have a rule saying iptables -I INPUT -i eth0 -j ACCEPT. Here comes my script (launched manually for tests) : #!/bin/sh IPT=/sbin/iptables echo "Clearing firewall rules" $IPT -F $IPT -Z $IPT -t nat -F $IPT -t nat -Z $IPT -t mangle -F $IPT -t mangle -Z $IPT -X echo "Defining logging policy for dropped packets" $IPT -N LOGDROP $IPT -A LOGDROP -j LOG -m limit --limit 5/min --log-level debug --log-prefix "iptables rejected: " $IPT -A LOGDROP -j DROP echo "Setting firewall policy" $IPT -P INPUT DROP # Deny all incoming connections $IPT -P OUTPUT ACCEPT # Allow all outgoing connections $IPT -P FORWARD DROP # Deny all forwaring echo "Allowing connections from/to lo and incoming connections from eth0" $IPT -I INPUT -i lo -j ACCEPT $IPT -I OUTPUT -o lo -j ACCEPT #$IPT -I INPUT -i eth0 -j ACCEPT echo "Setting SYN flood countermeasures" $IPT -A INPUT -p tcp -i eth0 --syn -m limit --limit 100/second --limit-burst 200 -j LOGDROP echo "Allowing outgoing traffic corresponding to already initiated connections" $IPT -A OUTPUT -p ALL -m state --state ESTABLISHED,RELATED -j ACCEPT echo "Allowing incoming SSH" $IPT -A INPUT -p tcp --dport 22 -m state --state NEW -m recent --set --name SSH -j ACCEPT echo "Setting SSH bruteforce attacks countermeasures (deny more than 10 connections every 10 minutes)" $IPT -A INPUT -p tcp --dport 22 -m recent --update --seconds 600 --hitcount 10 --rttl --name SSH -j LOGDROP echo "Allowing incoming traffic for HTTP, SMTP, NTP, PgSQL and SolR" $IPT -A INPUT -p tcp --dport 25 -i eth0 -j ACCEPT $IPT -A INPUT -p tcp --dport 80 -i eth0 -j ACCEPT $IPT -A INPUT -p udp --dport 123 -i eth0 -j ACCEPT $IPT -A INPUT -p tcp --dport 5433 -i eth0.2654 -s 172.16.0.2 -j ACCEPT $IPT -A INPUT -p udp --dport 5433 -i eth0.2654 -s 172.16.0.2 -j ACCEPT $IPT -A INPUT -p tcp --dport 8983 -i eth0.2654 -s 172.16.0.2 -j ACCEPT $IPT -A INPUT -p udp --dport 8983 -i eth0.2654 -s 172.16.0.2 -j ACCEPT echo "Allowing outgoing traffic for ICMP, SSH, whois, SMTP, DNS, HTTP, PgSQL and SolR" $IPT -A OUTPUT -p tcp --dport 22 -j ACCEPT $IPT -A OUTPUT -p tcp --dport 25 -o eth0 -j ACCEPT $IPT -A OUTPUT -p tcp --dport 43 -o eth0 -j ACCEPT $IPT -A OUTPUT -p tcp --dport 53 -o eth0 -j ACCEPT $IPT -A OUTPUT -p udp --dport 53 -o eth0 -j ACCEPT $IPT -A OUTPUT -p tcp --dport 80 -o eth0 -j ACCEPT $IPT -A OUTPUT -p udp --dport 80 -o eth0 -j ACCEPT #$IPT -A OUTPUT -p tcp --dport 5433 -o eth0 -d 176.31.236.101 -j ACCEPT #$IPT -A OUTPUT -p udp --dport 5433 -o eth0 -d 176.31.236.101 -j ACCEPT #$IPT -A OUTPUT -p tcp --dport 8983 -o eth0 -d 176.31.236.101 -j ACCEPT #$IPT -A OUTPUT -p udp --dport 8983 -o eth0 -d 176.31.236.101 -j ACCEPT $IPT -A OUTPUT -p tcp --sport 5433 -o eth0.2654 -j ACCEPT $IPT -A OUTPUT -p udp --sport 5433 -o eth0.2654 -j ACCEPT $IPT -A OUTPUT -p tcp --sport 8983 -o eth0.2654 -j ACCEPT $IPT -A OUTPUT -p udp --sport 8983 -o eth0.2654 -j ACCEPT $IPT -A OUTPUT -p icmp -j ACCEPT echo "Allowing outgoing FTP backup" $IPT -A OUTPUT -p tcp --dport 20:21 -o eth0 -d 91.121.190.78 -j ACCEPT echo "Dropping and logging everything else" $IPT -A INPUT -s 0/0 -j LOGDROP $IPT -A OUTPUT -j LOGDROP $IPT -A FORWARD -j LOGDROP echo "Firewall loaded." echo "Maintaining new rules for 3 minutes for tests" sleep 180 $IPT -nvL echo "Clearing firewall rules" $IPT -F $IPT -Z $IPT -t nat -F $IPT -t nat -Z $IPT -t mangle -F $IPT -t mangle -Z $IPT -X $IPT -P INPUT ACCEPT $IPT -P OUTPUT ACCEPT $IPT -P FORWARD ACCEPT When I launch this script (I only have a SSH access), the shell displays every message up to Maintaining new rules for 3 minutes for tests, the server is unresponsive during the 3 minutes delay and then resume normal operations. The only solution I found until now was to set $IPT -P INPUT ACCEPT and $IPT -I INPUT -i eth0 -j ACCEPT, but this configuration does not protect me of any attack, which is a great shame for a firewall. I suspect that the error comes from my script and not from iptables, but I don't understand what's wrong with my script. Could some do-gooder explain me my error, please? EDIT: here comes the result of iptables -nvL with the "accept all input" ($IPT -P INPUT ACCEPT and $IPT -I INPUT -i eth0 -j ACCEPT) solution : Chain INPUT (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 1 52 ACCEPT all -- eth0 * 0.0.0.0/0 0.0.0.0/0 0 0 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0 0 0 LOGDROP tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp flags:0x17/0x02 limit: avg 100/sec burst 200 0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 state NEW recent: SET name: SSH side: source 0 0 LOGDROP tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 recent: UPDATE seconds: 600 hit_count: 10 TTL-Match name: SSH side: source 0 0 ACCEPT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:25 0 0 ACCEPT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 0 0 ACCEPT udp -- eth0 * 0.0.0.0/0 0.0.0.0/0 udp dpt:123 0 0 ACCEPT tcp -- eth0.2654 * 172.16.0.2 0.0.0.0/0 tcp dpt:5433 0 0 ACCEPT udp -- eth0.2654 * 172.16.0.2 0.0.0.0/0 udp dpt:5433 0 0 ACCEPT tcp -- eth0.2654 * 172.16.0.2 0.0.0.0/0 tcp dpt:8983 0 0 ACCEPT udp -- eth0.2654 * 172.16.0.2 0.0.0.0/0 udp dpt:8983 0 0 LOGDROP all -- * * 0.0.0.0/0 0.0.0.0/0 Chain FORWARD (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 0 0 LOGDROP all -- * * 0.0.0.0/0 0.0.0.0/0 Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 0 0 ACCEPT all -- * lo 0.0.0.0/0 0.0.0.0/0 2 728 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED 0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp dpt:25 0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp dpt:43 0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp dpt:53 0 0 ACCEPT udp -- * eth0 0.0.0.0/0 0.0.0.0/0 udp dpt:53 0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 0 0 ACCEPT udp -- * eth0 0.0.0.0/0 0.0.0.0/0 udp dpt:80 0 0 ACCEPT tcp -- * eth0.2654 0.0.0.0/0 0.0.0.0/0 tcp spt:5433 0 0 ACCEPT udp -- * eth0.2654 0.0.0.0/0 0.0.0.0/0 udp spt:5433 0 0 ACCEPT tcp -- * eth0.2654 0.0.0.0/0 0.0.0.0/0 tcp spt:8983 0 0 ACCEPT udp -- * eth0.2654 0.0.0.0/0 0.0.0.0/0 udp spt:8983 0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 91.121.190.78 tcp dpts:20:21 0 0 LOGDROP all -- * * 0.0.0.0/0 0.0.0.0/0 Chain LOGDROP (5 references) pkts bytes target prot opt in out source destination 0 0 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 limit: avg 5/min burst 5 LOG flags 0 level 7 prefix `iptables rejected: ' 0 0 DROP all -- * * 0.0.0.0/0 0.0.0.0/0 EDIT #2 : I modified my script (policy ACCEPT, defining authorized incoming packets then logging and dropping everything else) to write iptables -nvL results to a file and to allow only 10 ICMP requests per second, logging and dropping everything else. The result proved unexpected : while the server was unavailable to SSH connections, even already established, I ping-flooded it from another server, and the ping rate was restricted to 10 requests per second. During this test, I also tried to open new SSH connections, which remained unanswered until the script flushed rules. Here comes the iptables stats written after these tests : Chain INPUT (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 600 35520 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0 6 360 LOGDROP tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp flags:0x17/0x02 limit: avg 100/sec burst 200 0 0 LOGDROP tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 STRING match "w00tw00t.at.ISC.SANS." ALGO name bm TO 65535 0 0 LOGDROP tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 STRING match "Host: anoticiapb.com.br" ALGO name bm TO 65535 0 0 LOGDROP tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 STRING match "Host: www.anoticiapb.com.br" ALGO name bm TO 65535 105 8820 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 limit: avg 10/sec burst 5 830 69720 LOGDROP icmp -- * * 0.0.0.0/0 0.0.0.0/0 0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 state NEW recent: SET name: SSH side: source 0 0 LOGDROP tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 recent: UPDATE seconds: 600 hit_count: 10 TTL-Match name: SSH side: source 0 0 ACCEPT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:25 0 0 ACCEPT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 0 0 ACCEPT udp -- eth0 * 0.0.0.0/0 0.0.0.0/0 udp dpt:80 0 0 ACCEPT udp -- eth0 * 0.0.0.0/0 0.0.0.0/0 udp dpt:123 0 0 ACCEPT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:443 0 0 ACCEPT tcp -- eth0.2654 * 172.16.0.1 0.0.0.0/0 tcp spt:5433 0 0 ACCEPT udp -- eth0.2654 * 172.16.0.1 0.0.0.0/0 udp spt:5433 0 0 ACCEPT tcp -- eth0.2654 * 172.16.0.1 0.0.0.0/0 tcp spt:8983 0 0 ACCEPT udp -- eth0.2654 * 172.16.0.1 0.0.0.0/0 udp spt:8983 16 1684 LOGDROP all -- * * 0.0.0.0/0 0.0.0.0/0 Chain FORWARD (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 0 0 LOGDROP all -- * * 0.0.0.0/0 0.0.0.0/0 Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot opt in out source destination 600 35520 ACCEPT all -- * lo 0.0.0.0/0 0.0.0.0/0 0 0 LOGDROP tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 owner UID match 33 0 0 LOGDROP udp -- * eth0 0.0.0.0/0 0.0.0.0/0 udp dpt:80 owner UID match 33 116 11136 ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED 0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp dpt:25 0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp dpt:53 0 0 ACCEPT udp -- * eth0 0.0.0.0/0 0.0.0.0/0 udp dpt:53 0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 0 0 ACCEPT udp -- * eth0 0.0.0.0/0 0.0.0.0/0 udp dpt:80 0 0 ACCEPT tcp -- * eth0.2654 0.0.0.0/0 0.0.0.0/0 tcp dpt:5433 0 0 ACCEPT udp -- * eth0.2654 0.0.0.0/0 0.0.0.0/0 udp dpt:5433 0 0 ACCEPT tcp -- * eth0.2654 0.0.0.0/0 0.0.0.0/0 tcp dpt:8983 0 0 ACCEPT udp -- * eth0.2654 0.0.0.0/0 0.0.0.0/0 udp dpt:8983 0 0 ACCEPT icmp -- * * 0.0.0.0/0 0.0.0.0/0 0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp dpt:43 0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 91.121.190.18 tcp dpts:20:21 7 1249 LOGDROP all -- * * 0.0.0.0/0 0.0.0.0/0 Chain LOGDROP (11 references) pkts bytes target prot opt in out source destination 35 3156 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 limit: avg 1/sec burst 5 LOG flags 0 level 7 prefix `iptables rejected: ' 859 73013 DROP all -- * * 0.0.0.0/0 0.0.0.0/0 Here comes the log content added during this test : Mar 28 09:52:51 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=52 TOS=0x00 PREC=0x00 TTL=51 ID=55666 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK URGP=0 Mar 28 09:52:51 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=52 TOS=0x00 PREC=0x00 TTL=51 ID=55667 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK URGP=0 Mar 28 09:52:51 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=64 TOS=0x00 PREC=0x00 TTL=51 ID=55668 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK URGP=0 Mar 28 09:52:51 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=64 TOS=0x00 PREC=0x00 TTL=51 ID=55669 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK URGP=0 Mar 28 09:52:52 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=64 TOS=0x00 PREC=0x00 TTL=51 ID=55670 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK URGP=0 Mar 28 09:52:54 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=64 TOS=0x00 PREC=0x00 TTL=51 ID=55671 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK URGP=0 Mar 28 09:52:58 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=64 TOS=0x00 PREC=0x00 TTL=51 ID=55672 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK URGP=0 Mar 28 09:52:59 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=6 Mar 28 09:52:59 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=7 Mar 28 09:52:59 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=8 Mar 28 09:52:59 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=9 Mar 28 09:52:59 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=59 Mar 28 09:53:00 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=152 Mar 28 09:53:01 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=246 Mar 28 09:53:02 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=339 Mar 28 09:53:03 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=432 Mar 28 09:53:04 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=524 Mar 28 09:53:05 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=617 Mar 28 09:53:06 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=711 Mar 28 09:53:07 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=804 Mar 28 09:53:08 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=176.31.236.101 DST=176.31.238.3 LEN=84 TOS=0x00 PREC=0x00 TTL=63 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=7430 SEQ=897 Mar 28 09:53:16 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:c0:62:6b:e3:5c:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=60 TOS=0x00 PREC=0x00 TTL=51 ID=61402 DF PROTO=TCP SPT=57637 DPT=22 WINDOW=5840 RES=0x00 SYN URGP=0 Mar 28 09:53:19 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:c0:62:6b:e3:5c:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=60 TOS=0x00 PREC=0x00 TTL=51 ID=61403 DF PROTO=TCP SPT=57637 DPT=22 WINDOW=5840 RES=0x00 SYN URGP=0 Mar 28 09:53:21 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=64 TOS=0x00 PREC=0x00 TTL=51 ID=55674 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK URGP=0 Mar 28 09:53:25 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:c0:62:6b:e3:5c:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=60 TOS=0x00 PREC=0x00 TTL=51 ID=61404 DF PROTO=TCP SPT=57637 DPT=22 WINDOW=5840 RES=0x00 SYN URGP=0 Mar 28 09:53:37 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=116 TOS=0x00 PREC=0x00 TTL=51 ID=55675 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK PSH URGP=0 Mar 28 09:53:37 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=116 TOS=0x00 PREC=0x00 TTL=51 ID=55676 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK PSH URGP=0 Mar 28 09:53:37 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=180 TOS=0x00 PREC=0x00 TTL=51 ID=55677 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK PSH URGP=0 Mar 28 09:53:38 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=180 TOS=0x00 PREC=0x00 TTL=51 ID=55678 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK PSH URGP=0 Mar 28 09:53:39 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=180 TOS=0x00 PREC=0x00 TTL=51 ID=55679 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK PSH URGP=0 Mar 28 09:53:39 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:c0:62:6b:e3:5c:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=60 TOS=0x00 PREC=0x00 TTL=51 ID=5055 DF PROTO=TCP SPT=57638 DPT=22 WINDOW=5840 RES=0x00 SYN URGP=0 Mar 28 09:53:41 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=180 TOS=0x00 PREC=0x00 TTL=51 ID=55680 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK PSH URGP=0 Mar 28 09:53:42 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:c0:62:6b:e3:5c:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=60 TOS=0x00 PREC=0x00 TTL=51 ID=5056 DF PROTO=TCP SPT=57638 DPT=22 WINDOW=5840 RES=0x00 SYN URGP=0 Mar 28 09:53:45 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:10:8c:cf:28:39:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=180 TOS=0x00 PREC=0x00 TTL=51 ID=55681 DF PROTO=TCP SPT=57504 DPT=22 WINDOW=501 RES=0x00 ACK PSH URGP=0 Mar 28 09:53:48 localhost kernel: iptables rejected: IN=eth0 OUT= MAC=00:25:90:54:d7:88:c0:62:6b:e3:5c:80:08:00 SRC=194.51.74.245 DST=176.31.238.3 LEN=60 TOS=0x00 PREC=0x00 TTL=51 ID=5057 DF PROTO=TCP SPT=57638 DPT=22 WINDOW=5840 RES=0x00 SYN URGP=0 If I correctly interpreted these results, they say that ICMP rules were correctly interpreted by iptables, but SSH rules were not. This does not make any sense... Does somebody understand where my error comes from? EDIT #3 : After some more tests, I found out that commenting the SYN flood countermeasure removes the problem. I continue researches in this way but, meanwhile, if somebody sees my anti SYN flood rule error...

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Doubt about adopting CI (Hudson) into an existing automated Build Process (phing, svn)

- by maraspin

OUR CURRENT BUILD PROCESS We're a small team of developers (2 to 4 people depending on project) who currently use Phing to deploy code to a staging environment, before going live. We keep our code in a SVN repo, where the trunk holds current active development and, at certain times, we do make branches that we test and then (if successful), tag and export to the staging env. If everything goes well there too, we finally deploy'em in production servers. Actions are highly automated, but always triggered by human intervention. THE DOUBT We'd now like to introduce Continuous Integration (with Hudson) in the process; unfortunately we have a few doubts about activity syncing, since we're afraid that CI could somewhat interfere with our build process and cause certain problems. Considering that an automated CI cycle has a certain frequency of automatically executed actions, we in fact only see 2 possible cases for "integration", each with its own problems: Case A: each CI cycle produces a new branch with its own name; we do use such a name to manually (through phing as it happens now) export the code from the SVN to the staging env. The problem I see here is that (unless specific countermeasures are taken) the number of branches we have can grow out of control (let's suppose we commit often, so that we have a fresh new build/branch every N minutes). Case B: each CI cycle creates a new branch named 'current', for instance, which is tagged with a unique name only when we manually decide to export it to staging; the current branch, at any case is then deleted, as soon as the next CI cycle starts up. The problem we see here is that a new cycle could kick in while someone is tagging/exporting the 'current' branch to staging thus creating an inconsistent build (but maybe here I'm just too pessimist, since I confess I don't know whether SVN offers some built-in protection against this). With all this being said, I was wondering if anyone with similar experiences could be so kind to give us some hints on the subject, since none of the approaches depicted above looks completely satisfing to us. Is there something important we just completely left off in the overall picture? Thanks for your attention &, in advance, for your help!

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How to Sync CI (Hudson) Activity into an existing automated Build Process (phing, svn)?

- by maraspin

OUR CURRENT BUILD PROCESS We're a small team of developers (2 to 4 people depending on project) who currently use Phing to deploy code to a staging environment, before going live. We keep our code in a SVN repo, where the trunk holds current active development and, at certain times, we do make branches that we test and then (if successful), tag and export to the staging env. If everything goes well there too, we finally deploy'em in production servers. Actions are highly automated, but always triggered by human intervention. THE DOUBT We'd now like to introduce Continuous Integration (with Hudson) in the process; unfortunately we have a few doubts about activity syncing, since we're afraid that CI could somewhat interfere with our build process and cause certain problems. Considering that an automated CI cycle has a certain frequency of automatically executed actions, we see 2 possible cases for "integration", each with its own problems: Case A: each CI cycle produces a new branch with its own name; we do use such a name to manually (through phing as it happens now) export the code from the SVN to the staging env. The problem I see here is that (unless specific countermeasures are taken - IE deletion) the number of branches we have can easily grow out of control (let's suppose we commit often, so that we have a fresh new build/branch every N minutes). Case B: each CI cycle creates a new branch named 'current', which is then tagged with a unique name only when we manually decide to export it to staging; the current branch, at any case is then deleted, as soon as the next CI cycle starts up. The problem we see here is that a new cycle could kick in while someone is tagging/exporting the 'current' branch to staging thus creating an inconsistent build (but maybe here I'm just too pessimist, since I confess I don't know whether SVN offers some built-in protection against this). With all this being said, I was wondering if anyone with similar experiences could be so kind to give us some hints on the subject, since none of the approaches depicted above looks completely satisfing to us. Is there something important we just completely left off in the overall picture? Thanks for your attention & (in advance) for your help!

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