Permission denied for nfs mount

I have an nfs server which is exporting 2 directories. My client can see the directories with showmount -e servername. But automount fails when I nixos-rebuild switch, and if I try to manually mount I get mount.nfs: access denied by server while mounting (null).

I should add that I followed the docs in this setup. I can paste the relevant portions if that helps.

I appreciate help with this. Thanks in advance.

Test manually by mounting the NFS shares using the mount command with the -t nfs option? Or use ip address instead of hostname. Are you able to ping or use traceroute ?

It was in trying to mount manually that I received the above error. Same thing using ip instead of hostname. Ping and ash work in both directions except for password-less authentication, another issue I’m trying to resolve.

Thanks for the ideas.