Date: Thu, 31 Aug 2023 20:18:15 +0000 From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 221122] Attaching interface to a bridge stops all traffic on uplink NIC for few seconds Message-ID: <bug-221122-7501-YV6wHqfLi9@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-221122-7501@https.bugs.freebsd.org/bugzilla/> References: <bug-221122-7501@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D221122 --- Comment #33 from spork@bway.net --- Some additional testing here... There are two workarounds presented in this thread: - Add "-txcsum -tso4 -tso6 -txcsum6" (or whatever your NIC requires) to the ifconfig statement for your interface(s) in rc.conf. This requires knowing = what you need to disable to make sure your NIC and epair have equal capabilities= so that when the epair interface is added to the bridge, there's no need to re= init the NIC to make the capabilities match, and therefore, no connectivity loss. - Pre-plumb the bridge and epair interfaces by adding them to rc.conf's cloned_interfaces and add the epair to the "addm" ifconfig line. On boot, t= he "addm" runs and we don't care about the reinit of the NIC because it's duri= ng boot. This method does not require knowing what capabilities need to be disabled on the NIC. I'm finding neither of these actually work as workarounds, because in 13.2 = with my ixl NICs I can see both with iocage (a jail shutdown or restart) and with manual ifconfig commands (removing a vtnet interface from a bridge) cause t= he NIC to reinit. In other words, removing an epair/vtnet interface from a bri= dge seems to put the offloading capabilities back in place, rendering either workaround useless. Again, I'm not clear on what the fix was that was mentioned in comment #28,= so if I'm way off base here, let me know! Example follows... We have a bridge containing my external ixl interface and an epair/vtnet interface from a jail: [root@clweb5 /home/spork]# ifconfig bridge0 bridge0: flags=3D8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu = 1500 ether 58:9c:fc:10:ff:d9 id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15 maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200 root id 00:00:00:00:00:00 priority 32768 ifcost 0 port 0 member: vnet0.10 flags=3D143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP> ifmaxaddr 0 port 7 priority 128 path cost 2000 member: ext0 flags=3D143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP> ifmaxaddr 0 port 1 priority 128 path cost 55 groups: bridge nd6 options=3D9<PERFORMNUD,IFDISABLED> The ext0 (ixl) interface was already a member of the bridge when the jail started to there was NO NIC reinit/loss of connectivity when the jail start= ed (good!). ext0 options look like this while a member of bridge0 (ie: txcsum and two f= or v4 and v6 are disabled): ext0: flags=3D8963<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0= mtu 1500 =20=20=20=20=20=20=20 options=3D4a500b9<RXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,VLAN= _HWFILTER,VLAN_HWTSO,RXCSUM_IPV6,NOMAP> Now I manually pull vtnet0.10 from the above bridge: [root@clweb5 /home/spork]# ifconfig bridge0 deletem vnet0.10 And we see connectivity drop for 5 seconds: Aug 31 15:32:57 clweb5 kernel: vnet0.10: promiscuous mode disabled Aug 31 15:32:57 clweb5 kernel: ext0: link state changed to DOWN Aug 31 15:33:02 clweb5 kernel: ext0: Link is up, 1 Gbps Full Duplex, Reques= ted FEC: None, Negotiated FEC: None, Autoneg: True, Flow Control: None Aug 31 15:33:02 clweb5 kernel: ext0: link state changed to UP And we see why - removing the vtnet bridge member causes something(?) to put all the flags I'd removed from ext0 back in place (txcsum, txcsum6, tso4, tso6): [root@clweb5 /home/spork]# ifconfig ext0 ext0: flags=3D8963<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0= mtu 1500 =20=20=20=20=20=20=20 options=3D4e503bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCS= UM,TSO4,TSO6,VLAN_HWFILTER,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,NOMAP> Again, this is me manually removing the interface from the bridge, not ioca= ge. Standard jails and iocage jails both call a "destroy" on the vtnet/epair interface, so this isn't just an iocage issue. Sorry this is so long... anyhow the questions again: - Did the prior workarounds "work" and then stop working later? - Did the behavior of bringing explicitly-removed flags back to an interface when members are removed from a bridge change at some point? - What was the fix in comment #28? --=20 You are receiving this mail because: You are the assignee for the bug.=
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