Here are the steps to configure the peer link on SwitchA:

Enter Configuration Mode:

SwitchA# configure terminal

Create VLAN 101:

SwitchA(config)# vlan 101

Create Port-Channel 100:

SwitchA(config)# interface port-channel 100

SwitchA(config-if-po100)# switchport mode trunk

SwitchA(config-if-po100)# switchport trunk allowed vlan 101

SwitchA(config-if-po100)# exit

Assign Physical Interfaces to Port-Channel 100:

SwitchA(config)# interface ethernet 1/5

SwitchA(config-if-eth1/5)# channel-group 100 mode active

SwitchA(config-if-eth1/5)# exit

SwitchA(config)# interface ethernet 1/6

SwitchA(config-if-eth1/6)# channel-group 100 mode active

SwitchA(config-if-eth1/6)# exit

Configure MC-LAG Domain 1:

SwitchA(config)# mclag domain 1

SwitchA(config-mclag-domain)# peer-link port-channel 100

SwitchA(config-mclag-domain)# local-ip 192.168.1.1

SwitchA(config-mclag-domain)# peer-ip 192.168.1.2

SwitchA(config-mclag-domain)# system-mac 00:00:00:11:11:11

SwitchA(config-mclag-domain)# exit

Save Configuration:

SwitchA# write memory

Comprehensive Detailed Step by Step Explanation with References:

Enter Configuration Mode:

Begin by entering the global configuration mode to make changes to the switch configuration.

Create VLAN 101:

Create VLAN 101 to be used for the MC-LAG peer link communication.

Create Port-Channel 100:

Enter the port channel interface configuration mode using interface port-channel 100.

Set the port channel to trunk mode with switchport mode trunk.

Allow VLAN 101 on the trunk with switchport trunk allowed vlan 101.

Exit the port channel interface configuration mode.

Assign Physical Interfaces to Port-Channel 100:

Enter interface configuration mode for ethernet 1/5 and assign it to port channel 100 using the channel-group 100 mode active command.

Exit the interface configuration mode.

Repeat the same steps for ethernet 1/6.

Configure MC-LAG Domain 1:

Enter the MC-LAG domain configuration mode using mclag domain 1.

Specify the peer link port channel with peer-link port-channel 100.

Configure the local IP address as 192.168.1.1 using local-ip 192.168.1.1.

Configure the peer IP address as 192.168.1.2 using peer-ip 192.168.1.2.

Set the MC-LAG system MAC address using system-mac 00:00:00:11:11:11.

Exit the MC-LAG domain configuration mode.

Save Configuration:

Save the configuration to ensure the changes persist after a reboot using the write memory command.

References:

Dell Technologies Networking - SONiC

Dell Enterprise SONiC Deployment Guide

These steps provide a comprehensive guide to configure the peer link for an MC-LAG scenario on SwitchA, ensuring the specific requirements for IP addressing, VLAN configuration, and port channel setup are met.