> Hi Ben, > > On Dec 13, 2006, at 4:02 AM, Ben Rockwood wrote: > > > I've got a network on which a number of Galaxy > systems are using > > link aggregation on 2 e1000g interfaces. It works > well. And thats > > what puzzles me. None of the switches were > configured to aggregate > > ports, LACP isn't enabled on the switch or on the > systems, and yet > > the aggr's seem fine, we're not seeing errors on > the ports, etc. > > It seems to me that this shouldn't work. > > > > Can anyone help me understand why aggr's work > without the switch > > having any knowledge of the configuration on the > system? Does this > > present problems that I haven't yet encountered or > perhaps simply > > don't know to look for? Given that we're using > Dell PowerConect > > switches which limit aggr groups to 8 even on a 48 > port switch I'm > > inclined to leave the setup alone unless I find a > good reason to > > stop aggregating in this way. Inquiring minds want > to know. > > It appears to be working, but there might be side > effects which are > not obviously visible but can bite later. Let me try > to describe what > happens in this case and these possible problems: > > When LACP is turned off, Solaris assumes that a port > is part of the > aggregation as soon as its link is up and its link > speed and duplex > status compatible with the other ports of the > aggregation. Packets > will be sent through the members of the aggregation > according to the > configured outbound port policy. The switch will > receive these > packets. Unicast packets will be delivered by the > switch, but a first > problem is that broadcast packets sent by one of the > constituent of > the aggregation will be sent by the switch to the > other members of > the aggregation. This will cause unexpected broadcast > packets to be > received by the host, which can cause problems such > as these to show > up in your logs: > > Feb 16 15:01:00 host ip: [ID 903730 kern.warning] > WARNING: IP: > Hardware address 'xx:xx:xx:xx:xx:xx' trying to be our > address > yyy.yyy.yyy.yyy! > > On the path to the Solaris host, the misconfigured > switch doesn't > know that the ports connected to the host are > aggregated. However the > switch saw packets with a source address > corresponding to the > aggregation MAC address coming from these ports. So > the switch will > pick one of these ports to send packets to the host. > Even though > packets appear to be flowing, it can be problematic > since (a) > duplicate broadcast packets will be sent to the host, > (b) traffic > might not be properly spread through the different > ports of the > aggregation, and (c) packets for the same connection > could arrive > from different NICs, which can cause reordering of > packets, and a > mismatch between the interrupted CPUs and the CPUs to > which squeues > are bound. > > These side effects can cause performance problems, > hard to diagnose > error messages, and in general suboptimal use of the > hardware resources. > > With LACP, such misconfigurations are a lot easier to > detect, since > ports will not be enabled until the aggregation > successfully > completes the LACP exchange with the remote peer. To > avoid cases like > this, we're planning to enable LACP by default (see > 6433652). > > Let me know you have further questions. > > Nicolas. > > -- > Nicolas Droux - Solaris Networking - Sun > Microsystems, Inc. > [EMAIL PROTECTED] - http://blogs.sun.com/droux > > > > _______________________________________________ > networking-discuss mailing list > [email protected] >
I finally understand why I get the following error after I read your post. WARNING: IP: Hardware address '00:14:4f:2c:94:46' trying to be our address 010.1.1.100! The question from Ben is exactly what the setting I have except the LACP is enabled on the switch side. There is no other configuration on the switch side ex: grouping, etc. because the network guy say it is not necessary on a HP switch. If I enable the LACP on the Solaris side (active/passive) then I will not be able to ping the gateway. No more network available. Which part is mi-configured on the HP switch since the LACP is enabled on all 4 ports used by Solaris. Does trunking necessary on the HP switch side? network guy told me that all 4 ports are showing trunking after enable the aggr on the Solaris box. I am confused. Any help will be very appreciated! thanks, Tony This message posted from opensolaris.org _______________________________________________ networking-discuss mailing list [email protected]
