3Com Switch 4800G 24-Port Configuration Manual - page 22
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device, the packet is sent to this device; otherwise, the packet is discarded. Therefore, a bridge device
on your network must have a unique bridge MAC address. If two devices on your network have the
same bridge MAC addresses, bridge MAC address collision occurs and the communication fails.
An IRF virtual device communicates with external networks as a single device; therefore, it also has a
bridge MAC address. Typically, an IRF virtual device uses the bridge MAC address of the master as its
bridge MAC address.
Bridge MAC address collision causes communication failure, and bridge MAC address switching
causes traffic interruption. Therefore, configure the preservation time of the bridge MAC address of the
IRF virtual device:
z
Preserve for six minutes: When the master leaves, the bridge MAC address does not change
within six minutes. If the master does not come back when the preserve time is expired, the IRF
virtual device uses the bridge MAC address of the newly elected master as its bridge MAC address.
If the master leaves the IRF for a short time due to device reboot or link failure, this configuration
can reduce unnecessary switch of bridge MAC address and thus avoid traffic interruption.
z
Preserve permanently: No matter whether the master leaves the IRF virtual device or not, the
bridge MAC address of the IRF virtual device remains unchanged.
z
Not preserved: As soon as the master leaves, the IRF virtual device uses the bridge MAC address
of the newly elected master as its bridge MAC address.
Follow these steps to specify the preservation time of the bridge MAC address of an IRF virtual device:
To do…
Use the command…
Remarks
Enter system view
system-view —
Configure the bridge MAC address of the
IRF virtual device to be preserved
permanently when the master leaves
irf mac-address persistent always
Specify the preservation time of the bridge
MAC address of the IRF virtual device as 6
minutes when the master leaves
irf mac-address persistent timer
Configure that the bridge MAC address of
the IRF virtual device changes as soon as
the master leaves
undo irf mac-address persistent
Optional
By default, IRF bridge
MAC address is
preserved for 6
minutes after the
master leaves.
z
Bridge MAC address change may cause a temporary traffic interruption.
z
If two IRF virtual devices have the same bridge MAC address, they cannot be merged into one IRF
virtual device.
Enabling Auto Upgrade of Boot Files
z
If auto upgrade of boot files is disabled, when the software of slaves and that of the master are in
different versions, the new member or the member with a low priority will not boot normally. Update
the device version and add the device into the IRF virtual device again.