3Com 3C15500 - Network Director User Manual page 847

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