DUALTORT0:dhcp6_client needs to run with -u Loopback0 argument

[santoss3]

We do not triage issue for this repo. All issues are triaged in sonic-net/sonic-buildimage repo The dhcp6_client daemon in dhcp_relay docker needs to listen to Loopback0 interface for receiving the dhcp relay response send from the server.

Below is the snapshot

root@tor40-1:/# ps -ax PID TTY STAT TIME COMMAND 1 pts/0 Ss+ 0:00 /usr/bin/python3 /usr/local/bin/supervisord 13 pts/0 Sl 0:00 python3 /usr/bin/supervisor-proc-exit-listener --container-name dhcp_relay 16 pts/0 Sl 0:00 /usr/sbin/rsyslogd -n -iNONE 21 pts/0 S 0:00 python3 /usr/local/bin/containercfgd 183 pts/0 S 0:00 /usr/sbin/dhcp6relay -d 184 pts/0 Sl 0:00 /usr/sbin/dhcrelay -d -m discard -a %h:%p %P --name-alias-map-file /tmp/port-name-alias-map.txt -id Vlan1000 -U Loopback0 -dt -iu PortChannel101 -iu PortChannel102 -iu Port 188 pts/0 Sl 0:00 /usr/sbin/dhcpmon -id Vlan1000 -u Loopback0 -iu PortChannel101 -iu PortChannel102 -iu PortChannel103 -iu PortChannel104 -im eth0 209 pts/1 Ss 0:00 bash 215 pts/1 R+ 0:00 ps -ax