-----Original Message----- From: netfilter-admin@xxxxxxxxxxxxxxxxxxx [mailto:netfilter-admin@xxxxxxxxxxxxxxxxxxx] On Behalf Of Pawel Pilat Sent: Monday, June 21, 2004 1:59 AM To: netfilter@xxxxxxxxxxxxxxxxxxx Subject: ECN problem? Hello everyone, it's my first post on this list so plese understanding ... I think that i have problem with ECN , this is my situation: IN--->R--->ISP where: IN - my internal net R - my linux router (2.4.25, ipt-1.2.9) ISP - my ISP so when i trying to connect from internal net to Internet i expirencing very slow transfers (500 - 700 bps) but from router everything is ok (transfer rate 50 - 60 kbps) when i used tcpdump on external interfece on router i realized that my ISP sends to me in every TCP packet TOS field set to 0x03 (ECN-CT + ECN-CE) i think that is the problem i tried using: iptables -t mangle -A PREROUTING -i $EXTIF -j TOS --set-tos 0x00 but without any result my question is: 1.it is possible to set linux box to ignore this fields in packets? 2. there is another way to solve the problem? thank for advices best regards POSTER PL __________________________________ Do you Yahoo!? Take Yahoo! Mail with you! Get it on your mobile phone. http://mobile.yahoo.com/maildemo Most ISP have ECN enabled on their routers today, so this is not unusual. If the packets you are receiving from your ISP have Cx=1 (0x03) then this means it is indeed experiencing congestion, and if your box is also ECN enabled, then the congestion windows on both devices are probably being cut in half. This needs to be confirmed before you do anything. To confirm this, I would suggest that you first check and see if you box is ECN enabled by checking your kernel config for CONFIG_INET_ECN=y. If it is, check the two high-order bits of bite 13 of the suspect TCP packet headers to see if the congestion windows are being cut. If so, then this is probably a correct assumption on your part. If so, the easiest solution would be to disable ECN on your box. You would need to recompile the kernel to that of course. However, it would seem as though ECN is only doing its job and you may want to explore that avenue. ######################################################## This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. postmaster@xxxxxxxxxxxxxxx MailScanner at bandwidthco.com is for your absolute protection. ########################################################
