Reposting with some more information. I've set iptables to drop-n-log bad packets and here's what I'm getting when I try and connect to my squid server. I'm not sure why these packets are being dropped as my rules are setup to allow and forward connections to port 80. I'm not sure why port 113 is in the mix. The relavent machines are: 192.168.1.1 - squidbox 192.168.1.5 - backend WWW server 192.168.1.205 - testing box/client Jul 19 15:18:19 squidbox kernel: drop-n-log:IN= OUT=eth0 SRC=192.168.1.1 DST=192.168.1.205 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=0 DF PROTO=TCP SPT=43600 DPT=113 WINDOW=5840 RES=0x00 SYN URGP=0 Jul 19 15:18:19 squidbox kernel: drop-n-log:IN= OUT=eth0 SRC=192.168.1.1 DST=192.168.1.5 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=54027 DF PROTO=TCP SPT=43601 DPT=80 WINDOW=5840 RES=0x00 SYN URGP=0 Jul 19 15:18:19 squidbox kernel: drop-n-log:IN= OUT=eth0 SRC=192.168.1.1 DST=192.168.1.5 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=54028 DF PROTO=TCP SPT=43595 DPT=80 WINDOW=5840 RES=0x00 SYN URGP=0 Jul 19 15:18:22 squidbox kernel: drop-n-log:IN= OUT=eth0 SRC=192.168.1.1 DST=192.168.1.205 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=0 DF PROTO=TCP SPT=43600 DPT=113 WINDOW=5840 RES=0x00 SYN URGP=0 Jul 19 15:18:22 squidbox kernel: drop-n-log:IN= OUT=eth0 SRC=192.168.1.1 DST=192.168.1.5 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=54027 DF PROTO=TCP SPT=43601 DPT=80 WINDOW=5840 RES=0x00 SYN URGP=0 Jul 19 15:18:24 squidbox kernel: drop-n-log:IN= OUT=eth0 SRC=192.168.1.1 DST=192.168.1.205 LEN=1423 TOS=0x00 PREC=0x00 TTL=64 ID=33313 DF PROTO=TCP SPT=80 DPT=42536 WINDOW=6432 RES=0x00 ACK PSH FIN URGP=0 Jul 19 15:18:28 squidbox kernel: drop-n-log:IN= OUT=eth0 SRC=192.168.1.1 DST=192.168.1.205 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=0 DF PROTO=TCP SPT=43600 DPT=113 WINDOW=5840 RES=0x00 SYN URGP=0 Jul 19 15:18:28 squidbox kernel: drop-n-log:IN= OUT=eth0 SRC=192.168.1.1 DST=192.168.1.5 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=54027 DF PROTO=TCP SPT=43601 DPT=80 WINDOW=5840 RES=0x00 SYN URGP=0 Jul 19 15:18:41 squidbox kernel: drop-n-log:IN= OUT=eth0 SRC=192.168.1.1 DST=192.168.1.5 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=54027 DF PROTO=TCP SPT=43601 DPT=80 WINDOW=5840 RES=0x00 SYN URGP=0 Jul 19 15:18:45 squidbox kernel: drop-n-log:IN= OUT=eth0 SRC=192.168.1.1 DST=192.168.1.205 LEN=1423 TOS=0x00 PREC=0x00 TTL=64 ID=33332 DF PROTO=TCP SPT=80 DPT=42539 WINDOW=6432 RES=0x00 ACK PSH URGP=0 Jul 19 15:18:45 squidbox kernel: drop-n-log:IN= OUT=eth0 SRC=192.168.1.1 DST=192.168.1.205 LEN=1423 TOS=0x00 PREC=0x00 TTL=64 ID=33332 DF PROTO=TCP SPT=80 DPT=42539 WINDOW=6432 RES=0x00 ACK PSH FIN URGP=0 Jul 19 15:18:59 squidbox last message repeated 6 times Again, any assistance would be greatly appreciated. If you would like my complete iptables script, please let me know and I'll be happy to post. Thanks. --------------------- Jim Matthews ISS Systems Administrator Duke University - Perkins Library Box 90196 Durham, NC 27708 Email: jim.matthews@xxxxxxxx Voice: 919-660-5963 Fax: 919-684-6990 Jim Matthews/Libraries/Provost/Academic/Univ/Duke 07/15/2004 10:46 AM To netfilter@xxxxxxxxxxxxxxxxxxx cc Subject Squid Accelerator configuration Hi We have a backend web server. To off-load some of the load from the backend server, we have a Squid server in front. I am having an issue with my iptables configuration on my Squid box. Everything works correctly when I disable the firewall (no good), so I'm having problems with my rules on the Squid server. I want to configure the systems so that: -On Squid- -allow all requests from Internet to port 80 -allow all requests from WWW box to/from port 80 -On WWW- -allow all forwarded requests to/from Squid Box to port 80 -do not allow requests from Internet to port 80 Has anyone setup something similar? Any suggestions or pointers on how to configure this? Here is the ruleset I'm using on my Squid box: # Squid # These rules are to allow testing from the internal network - the first two rules are for the Squid port -A INPUT -s 192.168.1.0/24 -p tcp -m tcp --sport 1024: --dport squid -m state --state NEW,ESTABLISHED -j ACCEPT -A OUTPUT -s 192.168.1.0/24 -p tcp -m tcp --sport squid -m state --state ESTABLISHED -j ACCEPT # These two rules are for the http port -A INPUT -s 192.168.1.0/24 -p tcp -m tcp --sport 1024: --dport http -m state --state NEW,ESTABLISHED -j ACCEPT -A OUTPUT -s 192.168.1.0/24 -p tcp -m tcp --sport http -m state --state ESTABLISHED -j ACCEPT # These two rules should cover the forwarding of connections for the backend WWW server -A FORWARD -s 0/0 -d 192.168.1.5 -p TCP --sport 1024:65535 --dport 80 -j ACCEPT -A FORWARD -d 0/0 -s 192.168.1.5 -p TCP -m state --state ESTABLISHED -j ACCEPT Any help you could give would be greatly appreciated. Thanks. Thanks. --------------------- Jim Matthews ISS Systems Administrator Duke University - Perkins Library Box 90196 Durham, NC 27708 Email: jim.matthews@xxxxxxxx Voice: 919-660-5963 Fax: 919-684-6990
