Connectivity Guide

Loopback interfaces
A Loopback interface is a virtual interface where the software emulates an interface. Because a Loopback interface is not associated to
physical hardware entities, the Loopback interface status is not aected by hardware status changes.
Packets routed to a Loopback interface process locally to the OS10 device. Because this interface is not a physical interface, to provide
protocol stability you can congure routing protocols on this interface. You can place Loopback interfaces in default L3 mode.
• Enter the Loopback interface number in CONFIGURATION mode, from 0 to 16383.
interface loopback number
• Enter the Loopback interface number to view the conguration 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 congured by default. Link aggregation (LA) 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 trac. If a member port fails, the OS10 device redirects trac to the remaining ports.
A physical interface can belong to only one port-channel at a time. A port-channel must contain interfaces of the same interface type and
speed. OS10 supports a maximum of 128 port-channels, with up to thirty-two ports per channel.
To congure a port-channel, use the same conguration commands as the Ethernet port interfaces. Port-channels are transparent to
network congurations and manage as a single interface. For example, congure one IP address for the group, and use the IP address for
all routed trac on the port-channel.
By conguring 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, trac redistributes across the
three remaining interfaces.
Static
Port-channels are statically congured.
Dynamic Port-channels are dynamically congured using Link Aggregation Control Protocol (LACP).
Member ports of a LAG are added and programmed into the hardware based on the port ID, instead of the order the ports come up. Load
balancing yields predictable results across resets and reloads.
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Interfaces