Dell PowerSwitch S4128F-ON OS10 Enterprise Edition User Guide Release 10.4.0ER - Page 77

Loopback interfaces A loopback interface is a virtual interface in which the software emulates an interface. Because a loopback interface is not associated to physical hardware entities, the loopback interface status is not affected by hardware status changes. Packets routed to a loopback interface are processed locally to the OS10 device. Because this interface is not a physical interface, you can configure routing protocols on this interface to provide protocol stability. You can place loopback interfaces in default L3 mode. • Enter the loopback interface number in CONFIGURATION mode (0 to 16383). interface loopback number • Enter the loopback interface number to view the configuration in EXEC mode. show interface loopback number • Enter the loopback interface number to delete a loopback interface in CONFIGURATION mode. no interface loopback number View loopback interface OS10# show interface loopback 4 Loopback 4 is up, line protocol is up Hardware is unknown. Interface index is 102863300 Internet address is 120.120.120.120/24 Mode of IPv4 Address Assignment : MANUAL MTU 1532 bytes Flowcontrol rx false tx false ARP type: ARPA, ARP Timeout: 240 Last clearing of "show interface" counters : 00:00:11 Queuing strategy : fifo Input 0 packets, 0 bytes, 0 multicast Received 0 errors, 0 discarded Output 0 packets, 0 bytes, 0 multicast Output 0 errors, Output 0 invalid protocol Time since last interface status change : 00:00:11 Port-channel interfaces Port-channels are not configured by default. Link aggregation is a method of grouping multiple physical interfaces into a single logical interface - a link aggregation group (LAG) or port -channel. A port-channel aggregates the bandwidth of member links, provides redundancy, and load balances traffic. If a member port fails, the OS10 device redirects traffic to the remaining ports. A physical interface can belong to only one port-channel at a time, and a port-channel must contain interfaces of the same interface type and speed. OS10 supports up to 128 port-channels, with up to 32 10G or 40G ports per channel. To configure a port-channel, use the same configuration commands as for Ethernet port interfaces. Port-channels are transparent to network configurations and managed as a single interface. For example, configure one IP address for the group, and use the IP address for all routed traffic on the port-channel. By configuring port channels, you can create larger capacity interfaces by aggregating a group of lower speed links. For example, you can build a 40G interface by aggregating four 10G Ethernet interfaces together - if one of the four interfaces fails, traffic is redistributed across the three remaining interfaces. Static Dynamic Port-channels are statically configured. Port-channels are dynamically configured using link aggregation control protocol (LACP). Member ports of a LAG are added and programmed into the hardware in a predictable order based on the port ID, instead of in the order in which the ports come up. Load balancing yields predictable results across resets and reloads. Interfaces 77