I've been running with tcp_ecn=1 for years with no issue. Since ECN marking is making its way into more and more places, enabling it by default makes sense. In particular, it would go well with the recent addition of FQ-CoDel as the default queue management algorithm :)
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to procps in Ubuntu. https://bugs.launchpad.net/bugs/1773157 Title: procps outdated network options, old syncookies, new ecn update please. Status in procps package in Ubuntu: Confirmed Bug description: The ubuntu version of procps carries it's own /etc/sysctl.d/10 -network-security.conf file explicitly that appears not to be part of debian procps version. Firstly, the section about "# Turn on SYN-flood protections." (came from LP #57091 ) is now entirely outdated, upstream kernel has long since turned on syncookies by default, so setting this flag explicitly in 10-network-security.conf is entirely redundant likely since before ubuntu-14.04 . I would like the ubuntu-maintainer to remove that section entirely in cosmic onwards. [I am going to report debian the similarly outdated syncookies comments in sysctl.conf itself]. Secondly, I propose a new 10-network-tuning.conf with:- ============================================================================== # Allow ECN for outgoing connections. Starting with 4.2, there is an adaptive # fallback [enabled by default tcp_ecn_fallback option] preventing connection # loss even with ecn enabled, also ecn-intolerance is increasingly very rare. net.ipv4.tcp_ecn=1 ============================================================================== I know there is a (small) chance of issues/regressions with ECN enabled by default on outgoing but I'm quite sure the issue is very rare, like others notice [ref: 1 and 2 below]. Apple's selective enablements etc. show this works just as much as my own use for years and many similar reports. ECN actually being used for outgoing connections really helps with latency-reduction with modern routers (both core and edge) using queuing disciplines fq_codel or otherwise, able to mark rather than drop packets on ECN-enabled flows [helps latency and realtime applications]. Now we are just past LTS release is in my view the 'right time' to finally enable ECN [and obviously easy to revert!]. If this is disputed, in ANY case I strongly suggest at the very least a commented-out ECN section should be included, but 'defaults matter'!. I was going to suggest a non-default section about net.core.default_qdisc [ LP #1436945 ] but this appears to have been fixed upstream similarly. [1] https://www.ietf.org/proceedings/98/slides/slides-98-maprg-tcp-ecn-experience-with-enabling-ecn-on-the-internet-padma-bhooma-00.pdf [2] http://seclists.org/nanog/2015/Jun/675 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/procps/+bug/1773157/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
