From: Tom Eastep Sent: Sunday, May 06, 2012 9:11 PM To: [email protected]Subject: Re: [Shorewall-users] Output policy DROP withRELATED_DISPOSITION=DROPOn 5/6/12 9:35 AM, Sascha Sanches wrote: > Hi, >> I've been using Shorewall with satisfaction for some two years now. A > few > days ago I decided to try to tighten the configuration as much I could. > This > meant changing the OUTPUT policy to REJECT, and RELATED_DISPOSITION to > DROP,> while the INPUT policy has been set to REJECT. And, well, I ran into the > following problem: > > Whenever a TCP connection attempt is to be rejected, a related TCP RST> packet is sent. With RELATED_DISPOSITION set to DROP, this reply is > dropped,> leading to long timeouts. >> Is there currently any way to include a rule in the related section of > the> shorewall-rules file that allows outgoing TCP RST packets without using > Perl? I'm really not a Perl programmer whatsoever... > > Two example syslog messages: >> [2012-05-06 18:10:05] hq [kernel/-] [kern.debug]: SW:fw2net:LOG:REL2POL > IN= > OUT=eth0 SRC=79.170.93.130 DST=79.1.157.73 LEN=40 TOS=0x00 PREC=0x00 > TTL=64> ID=0 DF PROTO=TCP SPT=23 DPT=2794 WINDOW=0 RES=0x00 ACK RST URGP=0 > [2012-05-06 18:10:05] hq [kernel/-] [kern.debug]: SW:+fw2net:ACCEPT:IN=> OUT=eth0 SRC=79.170.93.130 DST=79.1.157.73 LEN=40 TOS=0x00 PREC=0x00 > TTL=64> ID=0 DF PROTO=TCP SPT=23 DPT=2794 WINDOW=0 RES=0x00 ACK RST URGP=0 > > The first message is a log rule at the end of the related section of the> rules file, and the second (I think) is about the same connection > attempt > and the result of RELATED_LOG_LEVEL=debug in shorewall.conf. As you can > see,> I've changed RELATED_DISPOSITION to ACCEPT right now, since that is the > easiest solution for now. Here's an action that matches RSTs. Be sure that you use the tcpflags option with this. -Tom PS -- be sure to add the action to your /etc/shorewall/actions file. -- Tom Eastep \ When I die, I want to go like my Grandfather who Shoreline, \ died peacefully in his sleep. Not screaming like Washington, USA \ all of the passengers in his car http://shorewall.net \________________________________________________
Hello Tom, Many thanks, your solution works perfectly!! Sascha.
action.RST
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