So I was trying to make an NFS server on my Linux box running Centos 7 and after successfully installing the NFS utilities and exporting a share called /nfsshare, I was trying to mount it on my client box. However when I ran the command showmount -e 10.100.76.4, which should show the existing mounts on the nfs server, I got the below error message.
clnt_create: RPC: Port mapper failure - Unable to receive: errno 113 (No route to host)
So I had to add some parameters on my NFS server's firewall and after that everything was fixed. On my NFS server I had to say:
firewall-cmd --permanent --add-service=mountd
firewall-cmd --permanent --add-service=nfs
firewall-cmd --permanent --add-service=rpc-bind