Usefull when nfs is open.
111/tcp open rpcbind 2-4 (RPC #100000)
| rpcinfo:
| program version port/proto service
| 100000 2,3,4 111/tcp rpcbind
| 100000 2,3,4 111/udp rpcbind
| 100000 3,4 111/tcp6 rpcbind
| 100000 3,4 111/udp6 rpcbind
| 100003 2,3,4 2049/tcp nfs
| 100003 2,3,4 2049/tcp6 nfs
| 100003 2,3,4 2049/udp nfs
| 100003 2,3,4 2049/udp6 nfs
| 100005 1,2,3 40412/udp mountd
| 100005 1,2,3 51233/tcp6 mountd
| 100005 1,2,3 57722/tcp mountd
| 100005 1,2,3 59004/udp6 mountd
| 100021 1,3,4 37539/tcp6 nlockmgr
| 100021 1,3,4 42654/udp nlockmgr
| 100021 1,3,4 49656/udp6 nlockmgr
| 100021 1,3,4 54775/tcp nlockmgr
| 100024 1 38568/tcp status
| 100024 1 50138/udp status
| 100024 1 54698/udp6 status
| 100024 1 57281/tcp6 status
| 100227 2,3 2049/tcp nfs_acl
| 100227 2,3 2049/tcp6 nfs_acl
| 100227 2,3 2049/udp nfs_acl
|_ 100227 2,3 2049/udp6 nfs_acl
2049/tcp open nfs_acl 2-3 (RPC #100227)
showmount -e host