Rootless docker daemon not able to access host details

Below is the comparision-

Environment : Centos 7 (Kernel 4.x)

docker-ce 20.10.12 is installed on root user and we have “alias” called “acme” (maps to “alias.example.com” with ip “10.10.11.11”, assume this is LDAP server), start the container , from the container , we run “nslookup acme”, it gives the result especially both FQDN and ip.

When compared to docker-ce 20.10.12 installed as “rootless” (not on root user) especially this instruction, start the container, from the container, if we run “nslookup acme”, it doesnt return IP, mentions ‘server cant find…’.

So how do we fix this on rootless docker daemon ?

Yes firewall or iptables were disabled. Compared the docker network between root and rootless, both are using bridge with subnet IP 172.17.0.0/16 still from container running on rootless docker daemon is unable to access alias host (yes can access FQDN or IP).

Any suggestion?