Upstream ISP uses IP precedence bit to classify and rate limit Internet traffic. We see a 10 - 20% packet loss at our linux firewall when traffic is high (6-8Mbps traffic with precedence bit set). Testing with iperf, traffic is not dropped when IP precedence is not set. No TOS or tc/qdisc has been configured (latest 2.4 kernel and 1.2.11 netfilter). Tried iptables -A PREROUTING -t mangle -j TOS --set-tos Normal-Service Still had packet loss. Has anyone seen this? Suggestions for fix?
