1-7
the rules below, in the order specified. If the first rule does not apply, a second rule is tried, and so on,
until the only winner is found.
z
The current master, even if a new member has a higher priority. (When an IRF virtual device is
being formed, all member devices consider themselves as the master, so this principle is skipped)
z
A member with a higher priority.
z
A member with the longest system up-time. (The system up-time information of each device is
delivered through IRF hello packets)
z
A member with the lowest bridge MAC address.
Then, the IRF virtual device is formed and enters the next stage: IRF virtual device management and
maintenance.
z
The precision of the system up-time is six minutes. For example, if two member devices with the
same priority values reboot one after another within six minutes, they have the same system
up-time and the last role election rule mentioned above is applied. In other words, the one with the
lowest bridge MAC address wins.
z
Merge: The process of connecting two existing IRF virtual devices with cables. When two IRF
virtual devices are merged into one, an election is held, and members of the loser side reboot and
join the winner side as slaves.
z
Partition: For an IRF virtual device, IRF link failure or power-off of a member causes physical
disconnection between two devices. The process is called IRF virtual device partition.
IRF Virtual Device Management
After role election, an IRF virtual device is established: all member devices operate as one virtual
device on the network, and all resources on the member devices are processed by this virtual device
and managed by the master.
Member ID
An IRF virtual device uses member IDs to uniquely identify and manage its members. For a device that
does not support IRF, an interface is named GigabitEthernet 1/0/1, where the first number is always 1;
for a device that supports IRF, if its member ID is 2, the name of the interface is GigabitEthernet 2/0/1,
where the first number indicates the member ID of the device.
A member ID is ranges from 1 to 10 and defaults to 1. To ensure the uniqueness of member IDs, plan
and configure member IDs before member devices join the IRF virtual device.
When multiple devices form an IRF virtual device, a logical distributed device is formed. Each member
device acts as a card on the distributed device. The master acts as the active main board (AMB), the
slaves act as the standby main boards (SMBs), and each member device also acts as an interface
board.
As shown in
Figure 1-6
, an IRF virtual device comprises four members, which are numbered 1, 2, 3 and
4. When the IRF virtual device is established, it functions like a distributed device: slots 1,2, 3 and 4 are
