Topology Collection; Role Election - 3Com Switch 4800G 24-Port Configuration Manual

Figure 1-10 Correspondence in aggregate mode for two interface modules
Because the two physical IRF ports bound to an aggregate IRF port must be located on the same
interface module, two IRF ports (that is, two aggregate IRF ports) can only be bound to the two physical
IRF ports on each of the two interface modules respectively (as shown in
can only bind IRF-port 1 to physical IRF ports 1 and 2, and IRF-port 2 to physical ports 3 and 4.
If one dual-port interface module and one single-port interface module are installed, you can bind two
physical IRF ports on the dual-port interface module to the IRF port in aggregate mode, and bind the
physical IRF port on the single-port interface module to the other IRF port in non-aggregate mode. In
this situation, IRF-port 2 or IRF-port 1 can be bound to any physical port on the device, because only
one IRF port is needed on Switch B or Switch C.

Topology Collection

Each member exchanges hello packets with the directly connected neighbors to collect topology of the
IRF virtual device. The IRF hello packets carry the topology information, including IRF port connection
states, member IDs, priorities, and bridge MAC addresses.
Each member records its known topology information locally. At the startup of a member device, the
member device records topology information of the local device. When an IRF port of a member
becomes up, the member device sends its known topology information from this port periodically. Upon
receiving the topology information from the directly connected neighbor, the member device updates
the local topology information. After topology collection lasts for a period of time, all members have
obtained the complete topology information (known as topology convergence), and then the IRF virtual
device enters the next stage: role election.

Role Election

The process of defining the role (master or slave) of members is role election.
Role election is held when the topology changes, such as, forming an IRF virtual device, adding a new
member, leaving or failure of the master, or IRF virtual device merge. The master is elected based on
1-8
Figure 1-10). In addition, you