Two ubuntu servers: 10.0.8.2 is the client, 192.168.20.58 is the server.
Between the 2 machines, Ping works, ssh works (in both directions).

From 10.0.8.2

showmount -e 192.168.20.58
Export list for 192.168.20.58:
/imr/nfsshares/foobar 10.0.8.2


mount.nfs 192.168.20.58:/imr/nfsshares/foobar /var/data/foobar -v
mount.nfs: access denied by server while mounting (null)

Found several things online, tried them all and still can't find any log information anywhere.

On the server:

[email protected]:/var/log# cat /etc/hosts.allow
sendmail: all
ALL: 10.0.8.2

/etc/hosts.deny is all comments

How can I get a trail of log statements to figure this out? What does it take to get some logging so I have some idea of WHY it won't mount?

On the server:

[email protected]# nmap -sR RPC 192.168.20.58

Starting Nmap 5.21 ( http://nmap.org ) at 2012-07-04 21:16 CDT
Failed to resolve given hostname/IP: RPC.  Note that you can't use '/mask' AND '1-4,7,100-' style     IP ranges
Nmap scan report for 192.168.20.58
Host is up (0.0000060s latency).
Not shown: 988 closed ports
PORT     STATE SERVICE VERSION
22/tcp   open  unknown
80/tcp   open  unknown
111/tcp  open  unknown
139/tcp  open  unknown
445/tcp  open  unknown
902/tcp  open  unknown
2049/tcp open  unknown
3000/tcp open  unknown
5666/tcp open  unknown
8009/tcp open  unknown
8222/tcp open  unknown
8333/tcp open  unknown

Nmap done: 1 IP address (1 host up) scanned in 3.81 seconds

From the client:

[email protected]:~$ nmap -sR RPC 192.168.20.58

Starting Nmap 5.21 ( http://nmap.org ) at 2012-07-04 22:14 EDT
Failed to resolve given hostname/IP: RPC.  Note that you can't use '/mask' AND '1-4,7,100-' style IP ranges
Nmap scan report for 192.168.20.58
Host is up (0.73s latency).
Not shown: 988 closed ports
PORT     STATE SERVICE              VERSION
22/tcp   open  unknown
80/tcp   open  unknown
111/tcp  open  rpcbind (rpcbind V2) 2 (rpc #100000)
139/tcp  open  unknown
445/tcp  open  unknown
902/tcp  open  unknown
2049/tcp open  nfs (nfs V2-4)       2-4 (rpc #100003)
3000/tcp open  unknown
5666/tcp open  unknown
8009/tcp open  unknown
8222/tcp open  unknown
8333/tcp open  unknown

Nmap done: 1 IP address (1 host up) scanned in 191.56 seconds