2devices in the IRF fabric or on the link aggregations. IRF also simplifies the Layer 3 network topologybecause it reduces the number of routing peers.The network topology does not change when a device is added to or removed from the IRF fabric.As shown in Figure 2, Device A and Device B form a two-chassis IRF fabric. The fabric has four MPUs (oneactive and three standbys), and two times the number of interface cards that a single device provides.The IRF fabric manages the physical and software resources of Device A and Device B in a centralizedmanner.Figure 2 Two-chassis IRF fabric implementation schematic diagramSingle point of managementAn IRF fabric is accessible at a single IP address on the network. You can use this IP address to log inthrough any network port to manage all the devices in the fabric.For an SNMP NMS, an IRF fabric is one managed network node.Node redundancyIn an IRF fabric, one member works as the master to manage and control the entire IRF fabric. All theother members process services while backing up the master. When the master fails, all the othermember devices elect a new master from among them to take over without interrupting services.IRF linkAn IRFfabric isformed.Master(Member ID=1)Subordinate(Member ID=2)Active MPUDevice A(Member ID=1)Device B(Member ID=2)IRF physicalinterfaces IRF physicalinterfacesIRF-port 2 IRF-port 1NetworkinterfacesNetworkinterfacesIRFStandby MPUActive MPUStandby MPUIRF’s master MPUIRF’s standby MPUIRF’s standby MPUIRF’s standby MPU