I'm having an odd problem with link aggregation between an ESXi 5 host and a 3COM Baseline 2924-SFP Plus switch. This is a standalone ESXi host with a dual-port NIC card. The networking is set up with the management network and the VM Network on the same virtual switch. I set up the ESXi host for static link aggregation as per the Etherchannel link aggregation article in the knowledgebase: Sample configuration of EtherChannel / Link Aggregation Control Protocol (LACP) with ESXi/ESX and Cisco/HP switches (1004048).
On the 3COM switch, I created a static link aggregation group of two ports. The parameters on the switch for these ports are:
STP - enabled
Port Fast - disabled
Root Guard - disabled
Port State - Forwarding
Port Role - Designated
RSTP Link Type - Auto
Duplex Mode - Full
Flow Control - disabled
I'm not a switch maven, so I don't know what all of these parameters mean, but it's set up the same as all of the other ports on the switch.
The issue is that the management network becomes unavailable after a period of time. I can't connect to the host through any method and can't ping it. However, the virtual machines are operating normally and fully accessible. The other day, we did a test by disconnecting one of the ports from the switch, and the host became available again. Then I removed and recreated the LAG and was once again able to connect to the ESXi host through the VSphere client. I left a command line window open for a couple of hours constantly pinging the host IP address, and never saw a failed ping. However, a few days later I tried connecting to the host through VSphere again and got a connection error, and it won't ping again either.
I'm at a loss as to what's going on. Any ideas?