From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040207 Firefox/0.8 Description of problem: I am unable to connect to certain sites, eg. http://www.royalmail.co.uk, or to download suns jdk1.5.0-beta, http://javashoplm.sun.com/ECom/docs/Welcome.jsp?StoreId=22&PartDetailId=j2sdk-1.5.0-beta-oth-JPR&SiteId=JSC&TransactionId=noreg (this link is on the site http://java.sun.com/j2se/1.5.0/download.jsp, select download in the SDK column). I have seen this on two machines on completely different networks, where rebooting into windows with the same ip address allows the download to be performed flawlessly. Version-Release number of selected component (if applicable): kernel-smp-2.6.2-1.160 How reproducible: Always Steps to Reproduce: 1. go to http://java.sun.com/j2se/1.5.0/download.jsp 2. select download in the SDK column 3. wait for connection timeout Actual Results: connection timeout Expected Results: successfull download Additional info:
I found out that it is fixed by turning off TCP ECN, using echo 0 >/proc/sys/net/ipv4/tcp_ecn
not a bug, the sites in question need to update their routers to use RFC compliant firmware. Alternatively, you have the workaround you already discovered, which you can drop into /etc/sysctl.conf