Tue, May 26, 2009 at 06:32:42PM CEST, andy@xxxxxxxxxxxxx wrote: >On Tue, May 26, 2009 at 05:17:17PM +0200, Jiri Pirko wrote: >> [PATCH net-next] bonding: allow bond in mode balance-alb to work properly in bridge -try4.1 >> >> Hi all. >> >> The problem is described in following bugzilla: >> https://bugzilla.redhat.com/show_bug.cgi?id=487763 >> >> Basically here's what's going on. In every mode, bonding interface uses the same >> mac address for all enslaved devices (except fail_over_mac). Only balance-alb >> will simultaneously use multiple MAC addresses across different slaves. When you >> put this kind of bond device into a bridge it will only add one of mac adresses >> into a hash list of mac addresses, say X. This mac address is marked as local. >> But this bonding interface also has mac address Y. Now then packet arrives with >> destination address Y, this address is not marked as local and the packed looks >> like it needs to be forwarded. This packet is then lost which is wrong. >> >> Notice that interfaces can be added and removed from bond while it is in bridge. >> >> *** >> When the multiple addresses for bridge port approach failed to solve this issue >> due to STP I started to think other way to solve this. I returned to previous >> solution but tweaked one. >> >> This patch solves the situation in the bonding without touching bridge code. >> For every incoming frame to bonding the destination address is compared to >> current address of the slave device from which tha packet came. If these two >> match destination address is replaced by mac address of the master. This address >> is known by bridge so it is delivered properly. > >Did you test this with a bond with more than 2 ports? I ask because I >might also expect a check against all the members of the bond (rather >than simply the receiving device). Yes, my testing machine has 3 interfaces for bond. Works fine. > >That check would be quite expensive for every frame and I think the >scenario is quite unlikely based on the frequency of 'learning frames' >sent by the alb code (so the switch connected to the host should have >it's forwarding database correct), but it might be something to think >about in the future. As you can see, my previous patch did the checking vs all slaves. I tried this experimentally and searched address from the list and dev->dev_addr differs only when I unplug cable and mac swap occurs. Then one packet is lost. But there are many lost packet during the unplug anyway so.... > >> I experimentally tried that this works as good as searching through the slave >> list (v4 of this patch). >> >> I was forced to create a new header because I need to use >> compare_ether_addr_64bits() (defined in linux/etherdevice.h) in >> linux/netdevice.h. I've hit some cross include issues. I think that it's good >> to have skb_bond_should_drop() in a separate file anyway. >> >> Jirka >> >> >> Signed-off-by: Jiri Pirko <jpirko@xxxxxxxxxx> >> > >This certainly won't cure all of the problems that arise with bonding >and bridging interactions, but it's a step in the right direction. > >Acked-by: Andy Gospodarek <andy@xxxxxxxxxxxxx> > _______________________________________________ Bridge mailing list Bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/bridge
