> Ok .. So I give .. I have Cacti working great however can not get it to
talk
> with M0n0 wall ..
> Do I need to config a rule on the WAN interface to allow UDP 161 to come
in?

Yes, sort of. I setup a NAT rule and a firewall rule.  Maybe not both
necessary, but it works :->.

1) Go to Firewall->NAT then on the Inbound tab, click '+' to add a new rule,
then enter it as:

protocol  UDP
ext port range 161
NAT IP (ext IP): 10.0.0.1
Int port range: 161
Description: snmp mrtg

2) I can't remember if (1) created a rule which I modified, or I created the
rule myself. But it is as follows: Firewall->Rules. Under WAN interface add
a rule that is:

protocol: UDP
source: IP of computer polling yours (assuming an external computer!)
Port: *
Destination: 10.0.0.1
Port: 161
Description: NAT snmp mrtg

Hope this helps!

cheers, michael