I have found 2.6-test10.1.95, at least, has ECN turned on. This was breaking many websites for me. Many firewalls are known to have issues with ECN. One example is at least some PIX firewalls. Sadly it seems to more corporate the site, the more likely it is to break. Workarounds: echo 0 > /proc/sys/net/ipv4/tcp_ecn net.ipv4.tcp_ecn = 0 in /etc/sysctl.conf Fix: Recompile kernel without ECN support P.S. arjanv Please Fix!
