Agent Update 843Serial Update Utility, Serial Upgrade Utility, Software Update Utility, AgentUpdate Utility and Management Upgrade Utility.1 Downgrading devices - You should always read the agent softwarerelease notes before downgrading a device as not all agent software canbe overwritten with significantly older software.2 Switch 1100/3300 running agent version 2.52 or lower - There mayoccasionally be issues when updating devices from very early versions ofthe agent software. In particular, when updating 3Com SuperStack IISwitch 1100/3300 stacks with VLANs configured from versions earlierthan 2.52, you may lose communication with the device part waythrough the upgrade - this will appear as a timeout failure in the AgentUpdate Wizard. This is more likely to happen on larger stacks and/or ondevices with larger numbers of VLANs configured. If this does happen,reboot the device and try again. If it fails a second time, then you shoulduse the Software Upgrade Utility to upgrade the device directly.3 Switch 1100/3300, PS Hub and DS Hub 500 Stacks - Occasionally thesedevices will fail to update all of the units in the stack. If this happens, thentry the update again. If it fails a second time, then you should use theSoftware Update Utility to update the device directly.4 Switch 1100/3300, PS Hub and DS Hub 500 devices - There is a shortperiod during the update process when loss of connectivity or power willresult in the device becoming non-operational. The device will run up onits BOOT code, then you should use the Software Update Utility toupdate the device directly.5 DS Hub 500 devices - Trying to upgrade from units currently running 2.11to another version will only be successful on units that have managementmodules. (Normally only one Management Module is required per stack).If this is a problem, then you should use the Software Update Utility toupdate the device directly.6 Switch 4900 devices - Updating from version 2.04 or earlier may time outon a congested LAN. This is because if the initial TFTP transfer times outdue to packet loss, the transfer is not restarted by the device. If thishappens, then try the update again when the network is less busy.7 Webcache 1000/3000 - Agent update is only supported from softwareversion 2.00 or later. Devices running versions earlier than 2.00 should beupdated using the device's Web interface. If you attempt to update adevice running earlier software, it will fail with the error: "Failure - Devicenot readable. The update failed because it was not possible to read oneor more MIBs."
