Reviewed: https://review.openstack.org/244722 Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=47713f58701af9e27792230dd64daa3e20a4260b Submitter: Jenkins Branch: master
commit 47713f58701af9e27792230dd64daa3e20a4260b Author: sridhargaddam <[email protected]> Date: Thu Nov 12 15:49:15 2015 +0000 Support MTU advertisement using IPv6 RAs RFC4861 allows us to specify the Link MTU using IPv6 RAs. When advertise_mtu is set in the config, this patch supports advertising the LinkMTU using Router Advertisements. Partially Implements: blueprint mtu-selection-and-advertisement Closes-Bug: #1495444 Change-Id: I50d40cd3b8eabf1899461a80e729d5bd1e727f28 ** Changed in: neutron Status: In Progress => Fix Released -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to neutron. https://bugs.launchpad.net/bugs/1495444 Title: MTU Option should be included in ICMPv6 Router Advertisements Status in neutron: Fix Released Bug description: When using an overlay network on a physical network with standard Ethernet MTU (1500 octets), the instances' effective MTU is reduced. The Neutron Router should inform the nodes about this fact, by including the MTU Option in the ICMPv6 Router Advertisements it sends. The current situation leads to blackholing of traffic, as the absence of the MTU Option causes the instance to believe it will be able to successfully transmit 1500 octets large frames to the network. However, these will be silently discarded. The symptom of is usually that the TCP three-way handshake succeeds, but that the connection appears to hang the moment payload starts being transmitted. The MTU Option is documented here: https://tools.ietf.org/html/rfc4861#section-4.6.4. The corresponding radvd.conf option is called AdvLinkMTU. Note that the Neutron router is clearly aware of the reduced effective MTU, as it does use the corresponding DHCPv4 option to advertise it to instances/subnets using IPv4. I observe this problem on OpenStack Kilo. To manage notifications about this bug go to: https://bugs.launchpad.net/neutron/+bug/1495444/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : [email protected] Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
