@Kiran Balraj Thank you for contacting us!
From the details you provided, I see that replication for your Linux (ubuntu 18.04) VM is not progressing/stopped. Could you check if you have a proxy on the linux machine using the command -
echo $http_proxy If yes just remove that and retry.
DNS server config:
For on-premises machine you will have to go and change the settings. For Windows on the NIC settings and if linux then on resolv.conf file
If you are talking about Azure machines, you will have to change it at Vnet level.
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