We know what our task is at Linux Today this week. 😉 If you run
a Web site and expect to entertain Linux users, you’ll want to pay
close attention to this posting.
Executive Summary: Survey shows 8.3% of websites unreachable from an ECN capable client. Notable unreachable sites: www.amazon.com, www.ibm.com, www.sun.com, www.apple.com, www.intel.com, www.disney.com, www.espn.com, www.zdnet.com, www.ups.com, www.visa.com, abc.com, cbs.com, fox.com, sharkyextreme.com, www.linuxtoday.com, www.linuxstart.com, www.linuxplanet.com, www.linuxnewbie.org, www.linux-usb.org Firewalls are improperly rejecting connections, if they aren't fixed, there will be lots of complaining when the linux 2.4 kernel gets widespread deployment. Long version: The current 2.4 test kernels include support for "ECN" in the IP stack. You can read about it here: http://www.faqs.org/rfcs/rfc2481.html As the Internet grows, ECN is needed to provide better congestion management. Theoretically, a fully ECN enabled Internet would have ZERO packet loss. The "problem" is that ECN uses two previously unused bits in the IP header, and because of that many firewalls improperly drop or reject IP packets from a ECN capable host. There have been various postings to l-k about unreachable sites, I wondered how widespread the problem was. With the help of perl, and friends, I came up with list of 34,579 unique websites. The websites were plucked from the log file of a moderately busy proxy server that has about 10,000 users behind it. The sites in the list are sites that were contacted by the proxy server in the last 5 days. I wrote a perl script to connect to each website with ECN turned off, and if I could connect, then to turn on ECN and try again. The results: From the 34,579 sites I came up with, 33177 were up. Sites checked: 34,579 Sites responding: 33177 Responding sites rejecting ECN packets: 2741 (8.3% of responding sites) It took 12 hours to run the test. According to NetCraft, there are 19+ million websites. Did I sample enough sites? Mostly likely not, however, the 35k sites I checked probably are the most popular sites on the Internet. Maybe NetCraft should do an ECN check as part of their normal survey. If anyone is interested in the perl script, or the list of sites, let me know. Dax Kelson Guru Labs