BSD (MacOS) has already turned on flow labels by default and this does not seem to be causing any problems in the Internet. Let's go ahead and turn them on by default. We'll continue to monitor for any devices start choking on them.
Flow labels are important since they are the desired solution for network devices to perform ECMP and RSS (RFC6437 and RFC6438). Traditionally, devices perform a 5-tuple hash on packets that includes port numbers. For the most part, these devices can only compute 5-tuple hashes for TCP and UDP. This severely limits our ability to get good network load balancing for other protocols (IPIP, GRE,ESP, etc.), and hence we are limited in using other protocols. Unfortunately, this method is accepted as the de facto standard to the extent that there are several proposals to encapsulate protocols in UDP _just_ for the purposes for getting ECMP to work. With hosts generating flow labels and devices taking them as input into ECMP (several already do), we can start to fix this fundamental problem. This patch set: - Changes IPV6_FLOWINFO sockopt to be opt-out of flow labels for connections rather than opt-in - Disable flow label state ranges sysctl by default - Enable auto flow labels sysctl by default Tom Herbert (3): ipv6: Allow to connections to opt-out of flow labels ipv6: Disable flowlabel state ranges by default ipv6: Enable auto flow labels by default include/net/ipv6.h | 2 +- net/ipv6/af_inet6.c | 5 +++-- net/ipv6/ip6_gre.c | 4 ++-- net/ipv6/ip6_tunnel.c | 2 +- 4 files changed, 7 insertions(+), 6 deletions(-) -- 1.8.5.6 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
