It seems an important component to the failure scenario is the hardware. The customer equipment is a Cisco UCS chassis and the MAAS nodes are blades in that chassis. Even though we cannot find anything in configuration that specifically adds the vlan-0 tag (or priority tag), traffic between the blades goes out one node untagged and shows up tagged on the other node.
Some bugs/discussions around vlan-0 and UCS: https://quickview.cloudapps.cisco.com/quickview/bug/CSCuu29425 https://quickview.cloudapps.cisco.com/quickview/bug/CSCuz83183 https://bugs.launchpad.net/opencontrail/+bug/1457805 https://arstechnica.com/civis/viewtopic.php?f=10&t=1442797 https://lists.linuxfoundation.org/pipermail/fds-dev/2017-May/000710.html http://lists.openstack.org/pipermail/openstack-operators/2013-April/002777.html https://linux.oracle.com/pls/apex/f?p=102:2:::NO::P2_VC_ID,P2_VERSION:606,1.0 As a note, Cisco seems to suggest it's a bug in Linux, citing these two old posts: https://lists.openwall.net/netdev/2013/09/10/30 https://lists.linuxfoundation.org/pipermail/bridge/2015-July/009630.html But I'm not convinced they are valid since this vlan-0 tag problem only shows up with this specific Cisco hardware. It seems like there are multiple network related software projects (like ipxe, vpp, probably others) that are forced to deal with the special case of vlan 0 (priority tagging) being added by Cisco UCS switches because Cisco's stance is that they're not adding the tags. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1805920 Title: iPXE ignores vlan 0 traffic To manage notifications about this bug go to: https://bugs.launchpad.net/maas/+bug/1805920/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
