Enterprise LinuxToday: Why Can't My 2.4 Kernel See Some Web Sites?Apr 17, 2001, 18:29 (2 Talkback[s])
(Other stories by Scott Courtney)
"Your upgrade to kernel 2.4.0, or anything later, went perfectly, or so you thought. You downloaded all the files you needed, built the kernel, upgraded modutils, and booted. Voila! Working system! So you played around a bit, decided it was working fine, and went back to your normal work."
"Around noontime you decided to check your stock portfolio on E-Trade or to look at the financial news on the NASDAQ web site. "Gee!" you thought as your browser failed to connect, "It's amazing that both of these major financial sites are down at the same time!" So you went back to what you were doing. A couple of hours later they were still unreachable, and you began to wonder if the problem was really at their end, or at yours."
"...The problem with Linux 2.4.x and ECN is that not all of the existing routers and other devices on the Internet can support ECN. In fact, some older devices actually treat ECN packets as invalid, and discard them altogether. This explains the problem with NASDAQ and E-Trade's web sites, both of which (as of a few days ago) did not support ECN packets. There are other sites with this problem as well, and in fact Internet.com had to upgrade some of its own equipment several months ago as a result of this new protocol."