How Irf Works - H3C S5600 SERIES Operation Manual

download and load the software, and then restart the device, or manually change the fabric name to add
the device to the fabric. H3C S5600 series switches provide the IRF automatic fabric function, which
enables the device to automatically download the software and change the fabric name, thus reducing
the manual maintenance workload.
With IRF automatic fabric enabled, if inconsistency in software version or fabric name occurs when a
switch is added to a fabric, the system automatically performs the following operations:
If the software version of the local device is inconsistent with that of the device in the fabric, the
system automatically initiates a download request to the device with the smallest unit ID in the
fabric and downloads the software used by the device in the current fabric to the local device. Then
the device will automatically restart and be added to the fabric.
If the fabric name of the local device is inconsistent with that of the device in the fabric, the system
automatically ignores the inconsistency check of the fabric name and adds the device to the fabric.
Then the system automatically synchronizes the configurations to the device with the smallest unit
ID and changes the fabric name.
With the above operations completed, the device can be added to the fabric and work normally.
You need to enable the IRF automatic fabric function on all the devices including the newly added
device in the fabric to enable the newly added device to download software and discovery
neighbors and thus be added to the fabric normally.
You are recommended to set the Unit ID of the switch with the software to be downloaded to 1, and
thus ensure that the candidate switch can download a correct software version.

How IRF Works

When a fabric is established, the devices determine their respective roles in the fabric by comparing
their CPU MAC addresses. The device with the lowest CPU MAC address is elected as the master and
the other devices are slaves.
After the election, the fabric can operate normally. The following three functions of IRF can provide
simple configuration mode, enhanced network performance and perfect redundancy backup
mechanism for users.
DDM
Distributed Device Management (DDM) is a new device management mode provided by IRF. In normal
cases, a fabric can be considered as a single device. You can manage the entire fabric by logging onto
any device in the fabric with different logging modes. The devices in the fabric synchronize their
configurations by exchanging packets, thus ensuring stability of the fabric.
FTM program uses Unit ID, or device ID to distinguish between the devices in a fabric when you
manage them. On initialization of the IRF function, each device considers its Unit ID as 1 and after a
fabric connection is established, the FTM program automatically re-numbers the devices or you can
manually configure the Unit ID of them.
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