Replica Set in MongoDB by using IPs instead of domains? I want to use MongoDB in replica-set mode over 2 servers by IPs.But when I deployed the secondary one on other server, I faced the issues about connecting between 2 instance. For example, the primary located on server 192.168.1.1:27018 with hostname COM1 and the second located on server 192.168.1.2:27018 with hostname COM2. Despite of configuring like this

net:
    bindIp: 0.0.0.0, COM1|192.168.1.1, COM2|192.168.1.2
    port: 27018


But in MongoDB's log, it responses that cant hear from COM1:27018 or can find COM2:27018, I don't know how to map these addresses with these IPs. Please help me, thanks!
From your primary machine run the following command

mongo --host COM2 --port 27018 


You should be able to connect to the MongoDB running in the secondary node using the above command. If it fails to connect, check the following configuration settings


Check the bindIp settings of the secondary node configuration file, it should allow connection from 192.168.1.1:27018.
Check the port number 27018 is accepting inbound connections in the secondary node. If not add an entry in IP Table.
Check if secondary nodes hosts file is updated with primary machines DNS name
and IP Address.


Follow the same for Primary node as well and try to connect to each machine from other machine using the first command. If everything working fine you should be able to set up your replica set.