[Beowulf] Anyone know the LinkAggregation(Trunking) on a switch?

[Zhang Hui]

Hi,all

	I have got a problem with the trunking failover on a switch.  
	I have implemented the multi-machine Trunking(one link per machine).The packets can be distributed between the links/machines and be at last forwarded to a real server via the IPVS(by Zhang Wensong),like this:
 _
| |	      |------|	   ________
|.|__/\___|  1   |_____|      |
| |  ||   |______|     | real |
| |  ||trunk           |      |
| |	 ||	  |------|	   |server|
|.|__||___|  2   |_____|      |
|_|  \/   |______|     |______|
switch
 
	And when one link(to one machine) is down, the connection will be transfered to another link/machine, and to "server" at last,session kept.
	The problem is, when, for example, "1" is down, but the link to "1" is still up(judge from the LED for "1" on the switch).So the "switch" won't think "1" is down, and distribute packets to "1" as usual.Therefore the connection is down.
	Can't the switch sense the death of a machine,intrinsically? Or something wrone with the configuration of Trunking in the "switch"?
	By the way, the "switch" is a 3com SS3300TM 16986A one.
	Can anyone help me? Great appreciation to any reply.
 					

　　　　　　　　Zhang Hui
　　　　　　　　spacetiller at 163.com
　　　　　　　　　　2005-09-02