Date: Sun, 26 Nov 2000 17:56:12 -0500 (EST) From: thursday@altavista.net To: cjclark@alum.mit.edu Cc: freebsd-questions@freebsd.org Subject: re: your mail Message-ID: <00112617561277.08110@weba2.iname.net>
next in thread | raw e-mail | index | archive | help
--Boundary-=_OKWNlIDJEeNnUVlINZtiVOPgtkCI Content-Type: Text/Plain Content-Transfer-Encoding: 7bit Content-Description: text, unencoded >[Please wrap your lines at about 70 columns or so for >those of us with RFC compliant MUAs. All of your >paragraphs are on one line.] Sorry about that; using iname's webmail client. >> "Nov 25 13:44:47 saucer natd[147]: failed to write >> packet back (Permission denied) >> >> Nov 25 13:44:53 saucer last message repeated 4 times >> " >> >> My questions are: What's up with this? Is this due >> to my firewall rules, or something else? I have log >>no set in /etc/natd.conf, and I'd rather not see >> this message if it's not affecting performance. I >> never saw this before on my 3.4 system. > This is due to a packet that was processed by >natd(8) being dropped later in the firewall rules. >> If there are some relevant files I can attach to >> help troubleshooting, please let me know. >For the 'failed to write packet back' problem, a copy > of both >rc.firewall and output of 'ipfw show' are good if you >still need help >with those. Well...after poking around a bit, I've determined that the 'natd failed to write packet back' messages occur whenever there's a hit (from the outside world) on any of the websites hosted on this machine. But, I don't know why natd is seeing these. I've attached my rc.firewall (note, the outside IP isn't my real IP) and the output of 'ipfw show' (at the bottom of rc.firewall). Thanks! ---------------------------------------------------------------- Get your free email from AltaVista at http://altavista.iname.com --Boundary-=_OKWNlIDJEeNnUVlINZtiVOPgtkCI Content-Type: text/english Content-Transfer-Encoding: 7bit Content-Description: text, unencoded Content-Disposition: inline; filename=rc.firewall /sbin/ipfw -f flush /sbin/ipfw add divert natd all from any to any via rl0 /sbin/ipfw add pass all from any to any ############ # Setup system for firewall service. # $FreeBSD: src/etc/rc.firewall,v 1.19.2.2 1999/08/29 14:18:55 peter Exp $ # Suck in the configuration variables. #if [ -f /etc/defaults/rc.conf ]; then # . /etc/defaults/rc.conf if [ -f /etc/rc.conf ]; then . /etc/rc.conf fi ############ # Define the firewall type in /etc/rc.conf. Valid values are: # open - will allow anyone in # client - will try to protect just this machine # simple - will try to protect a whole network # closed - totally disables IP services except via lo0 interface # Unknown - disables the loading of firewall rules. # filename - will load the rules in the given filename (full path required) # # For ``client'' and ``simple'' the entries below should be customized # appropriately. ############ # # If you don't know enough about packet filtering, we suggest that you # take time to read this book: # # Building Internet Firewalls # Brent Chapman and Elizabeth Zwicky # # O'Reilly & Associates, Inc # ISBN 1-56592-124-0 # http://www.ora.com/ # # For a more advanced treatment of Internet Security read: # # Firewalls & Internet Security # Repelling the wily hacker # William R. Cheswick, Steven M. Bellowin # # Addison-Wesley # ISBN 0-201-6337-4 # http://www.awl.com/ # if [ "x$1" != "x" ]; then firewall_type=$1 fi ############ # Set quiet mode if requested if [ "x$firewall_quiet" = "xYES" ]; then fwcmd="/sbin/ipfw -q" else fwcmd="/sbin/ipfw" fi ############ # Flush out the list before we begin. $fwcmd -f flush ############ # These rules are required for using natd. All packets are passed to # natd before they encounter your remaining rules. The firewall rules # will then be run again on each packet after translation by natd, # minus any divert rules (see natd(8)). if [ "X${natd_enable}" = X"YES" ]; then $fwcmd add divert natd all from any to any via ${natd_interface} fi ############ # If you just configured ipfw in the kernel as a tool to solve network # problems or you just want to disallow some particular kinds of traffic # they you will want to change the default policy to open. You can also # do this as your only action by setting the firewall_type to ``open''. # $fwcmd add 65000 pass all from any to any ############ # Only in rare cases do you want to change these rules $fwcmd add 100 pass all from any to any via lo0 $fwcmd add 200 deny all from any to 127.0.0.0/8 # Prototype setups. if [ "${firewall_type}" = "open" -o "${firewall_type}" = "OPEN" ]; then $fwcmd add 65000 pass all from any to any elif [ "${firewall_type}" = "client" ]; then ############ # This is a prototype setup that will protect your system somewhat against # people from outside your own network. ############ # set these to your network and netmask and ip net="192.168.4.0" mask="255.255.255.0" ip="192.168.4.17" # Allow any traffic to or from my own net. $fwcmd add pass all from ${ip} to ${net}:${mask} $fwcmd add pass all from ${net}:${mask} to ${ip} # Allow TCP through if setup succeeded $fwcmd add pass tcp from any to any established # Allow setup of incoming email $fwcmd add pass tcp from any to ${ip} 25 setup # Allow setup of outgoing TCP connections only $fwcmd add pass tcp from ${ip} to any setup # Disallow setup of all other TCP connections $fwcmd add deny tcp from any to any setup # Allow DNS queries out in the world $fwcmd add pass udp from any 53 to ${ip} $fwcmd add pass udp from ${ip} to any 53 # Allow NTP queries out in the world $fwcmd add pass udp from any 123 to ${ip} $fwcmd add pass udp from ${ip} to any 123 # Everything else is denied as default. elif [ "${firewall_type}" = "simple" ]; then # 'simple' firewall taken from www.mostgraveconcern.com/freebsd # Outside interface network and netmask and ip oif="rl0" onet="212.17.132.0" omask="255.255.255.0" oip="212.17.132.172" # Inside interface network and netmask and ip iif="xl0" inet="192.168.1.0" imask="255.255.255.0" iip="192.168.1.1" # My ISP's DNS servers dns1="206.17.140.161" dns2="191.164.246.5" # Stop spoofing ${fwcmd} add deny log all from ${inet}:${imask} to any in via ${oif} ${fwcmd} add deny log all from ${onet}:${omask} to any in via ${iif} # Stop RFC1918 nets on the outside interface ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif} ${fwcmd} add deny all from any to 10.0.0.0/8 out via ${oif} ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif} ${fwcmd} add deny all from any to 172.16.0.0/12 out via ${oif} ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif} ${fwcmd} add deny all from any to 192.168.0.0/16 out via ${oif} # Stop draft-manning-dsua-01.txt nets on the outside interface ${fwcmd} add deny log all from 0.0.0.0/8 to any via ${oif} ${fwcmd} add deny log all from any to 0.0.0.0/8 via ${oif} ${fwcmd} add deny log all from 169.254.0.0/16 to any via ${oif} ${fwcmd} add deny log all from any to 169.254.0.0/16 via ${oif} ${fwcmd} add deny log all from 192.0.2.0/24 to any via ${oif} ${fwcmd} add deny log all from any to 192.0.2.0/24 via ${oif} ${fwcmd} add deny log all from 224.0.0.0/4 to any via ${oif} ${fwcmd} add deny log all from any to 224.0.0.0/4 via ${oif} ${fwcmd} add deny log all from 240.0.0.0/4 to any via ${oif} ${fwcmd} add deny log all from any to 240.0.0.0/4 via ${oif} # Allow established connections ${fwcmd} add pass tcp from any to any established # Allow IP fragments to pass through ${fwcmd} add pass all from any to any frag ### TCP SETUP RULES # HTTP - Allow access to our web server ${fwcmd} add pass tcp from any to any 80 setup # POP - Allow access to our POP3 server ${fwcmd} add pass log tcp from any to any 110 setup # SMTP - Allow access to sendmail for incoming e-mail ${fwcmd} add pass tcp from any to any 25 setup # FTP - Allow incoming data channel for outgoing connections, # Reject&Log all incoming control connections ${fwcmd} add pass tcp from any 20 to any 1024-65535 setup ${fwcmd} add pass log tcp from any to any 21 in via ${oif} setup # SSH Login - Allow & Log all incoming ${fwcmd} add pass log tcp from any to any 22 in via ${oif} setup # IDENT - Reset incoming connections ${fwcmd} add reset tcp from any to any 113 in via ${oif} setup # Reject&Log all setup of incoming connections from the outside ${fwcmd} add deny log tcp from any to any in via ${oif} setup # Allow setup of any other TCP connection ${fwcmd} add pass tcp from any to any setup ### UDP RULES # DNS - Allow queries out in the world #${fwcmd} add pass udp from any to any 53 #${fwcmd} add pass udp from any 53 to any ${fwcmd} add pass udp from any to ${dns1} 53 ${fwcmd} add pass udp from any to ${dns2} 53 ${fwcmd} add pass udp from ${dns1} 53 to any ${fwcmd} add pass udp from ${dns2} 53 to any # SMB - Allow local traffic ${fwcmd} add pass udp from any to any 137-139 via ${iif} # NTP - Allow server-to-server on outside interface, client-to-server # on inside interface ${fwcmd} add pass udp from any 123 to any 123 via ${oif} ${fwcmd} add pass udp from any 123 to any via ${iif} ${fwcmd} add pass udp from any to any 123 via ${iif} # TRACEROUTE - Allow outgoing, but not incoming ${fwcmd} add pass udp from any to any 33434-33523 out via ${oif} ### ICMP RULES # ICMP packets # Allow all ICMP packets on internal interface ${fwcmd} add pass icmp from any to any via ${iif} # Allow outgoing pings, but not incoming ${fwcmd} add pass icmp from any to any icmptypes 8 out via ${oif} ${fwcmd} add pass icmp from any to any icmptypes 0 in via ${oif} # Allow Destination Unreachable, Source Quench, Time Exceeded, and Bad Header ${fwcmd} add pass icmp from any to any icmptypes 3,4,11,12 via ${oif} # Deny the rest of them ${fwcmd} add deny icmp from any to any ### MISCELLANEOUS REJECT RULES # Reject broadcasts from outside interface ${fwcmd} add 63000 deny ip from any to 0.0.0.255:0.0.0.255 in via ${oif} # Reject&Log SMB connections on outside interface ${fwcmd} add 64000 deny log udp from any to any 137-139 via ${oif} # Reject&Log all other connections from outside interface ${fwcmd} add 65000 deny log ip from any to any via ${oif} fi --output of 'ipfw -show-- 00100 0 0 divert 8668 ip from any to any via rl0 00100 0 0 allow ip from any to any via lo0 00200 0 0 deny ip from any to 127.0.0.0/8 00300 0 0 deny log logamount 100 ip from 192.168.1.0/24 to any in recv rl0 00400 0 0 deny log logamount 100 ip from 212.17.132.0/24 to any in recv xl0 00500 0 0 deny ip from 10.0.0.0/8 to any via rl0 00600 0 0 deny ip from any to 10.0.0.0/8 out xmit rl0 00700 0 0 deny ip from 172.16.0.0/12 to any via rl0 00800 0 0 deny ip from any to 172.16.0.0/12 out xmit rl0 00900 0 0 deny ip from 192.168.0.0/16 to any via rl0 01000 0 0 deny ip from any to 192.168.0.0/16 out xmit rl0 01100 0 0 deny log logamount 100 ip from 0.0.0.0/8 to any via rl0 01200 0 0 deny log logamount 100 ip from any to 0.0.0.0/8 via rl0 01300 0 0 deny log logamount 100 ip from 169.254.0.0/16 to any via rl0 01400 0 0 deny log logamount 100 ip from any to 169.254.0.0/16 via rl0 01500 0 0 deny log logamount 100 ip from 192.0.2.0/24 to any via rl0 01600 0 0 deny log logamount 100 ip from any to 192.0.2.0/24 via rl0 01700 0 0 deny log logamount 100 ip from 224.0.0.0/4 to any via rl0 01800 0 0 deny log logamount 100 ip from any to 224.0.0.0/4 via rl0 01900 0 0 deny log logamount 100 ip from 240.0.0.0/4 to any via rl0 02000 0 0 deny log logamount 100 ip from any to 240.0.0.0/4 via rl0 02100 0 0 allow tcp from any to any established 02200 0 0 allow ip from any to any frag 02300 0 0 allow tcp from any to any 80 setup 02400 0 0 allow log logamount 100 tcp from any to any 110 setup 02500 0 0 allow tcp from any to any 25 setup 02600 0 0 allow tcp from any 20 to any 1024-65535 setup 02700 0 0 allow log logamount 100 tcp from any to any 21 in recv rl0 setup 02800 0 0 allow log logamount 100 tcp from any to any 22 in recv rl0 setup 02900 0 0 reset tcp from any to any 113 in recv rl0 setup 03000 0 0 deny log logamount 100 tcp from any to any in recv rl0 setup 03100 0 0 allow tcp from any to any setup 03200 0 0 allow udp from any to 206.17.140.161 53 03300 0 0 allow udp from any to 191.164.246.5 53 03400 0 0 allow udp from 206.17.140.161 53 to any 03500 0 0 allow udp from 191.164.246.5 53 to any 03600 0 0 allow udp from any to any 137-139 via xl0 03700 0 0 allow udp from any 123 to any 123 via rl0 03800 0 0 allow udp from any 123 to any via xl0 03900 0 0 allow udp from any to any 123 via xl0 04000 0 0 allow udp from any to any 33434-33523 out xmit rl0 04100 0 0 allow icmp from any to any via xl0 04200 0 0 allow icmp from any to any out xmit rl0 icmptype 8 04300 0 0 allow icmp from any to any in recv rl0 icmptype 0 04400 0 0 allow icmp from any to any via rl0 icmptype 3,4,11,12 04500 0 0 deny icmp from any to any 63000 0 0 deny ip from any to 0.0.0.255:0.0.0.255 in recv rl0 64000 0 0 deny log logamount 100 udp from any to any 137-139 via rl0 65000 0 0 deny log logamount 100 ip from any to any via rl0 65535 357 56075 allow ip from any to any --Boundary-=_OKWNlIDJEeNnUVlINZtiVOPgtkCI-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?00112617561277.08110>