Need to Reboot PFsense Frequently

[fraggle]

I have the following config:-

1 x WAN Connection
1 x LAN - Phone 1
1 x LAN - Phone 2
1 x LAN - Mngt

There are 2 keypad devices on Phone 1 & 2 keypad devices Phone 2. These communicate with a piece of software on 4 corresponding PCs on Mngt. There are firewall rules in place to allow only specific IP addresses on Phone 1 & Phone 2 to access Mngt (the keypads and the switchboards themselves)

It all works well for weeks at a time, when suddenly 1 or more of the PCs will not be able to communicate with its corresponding keypad. I can ping the keypads(s) from the PC but the software throws a communication error. If it's only 1 PC throwing the error, then the other PCs will still work perfectly, the Phone 1 and Phone 2 networks can still access the internet as can Mngt. Sometimes it's one PC, sometimes it's 2 across Phone 1 & Phone 2, sometimes it's 2 on the same LAN, or smetimes 3 or all four - no pattern or commonality involved. I've giben the keypads and PCs static addresses and thats made no difference.

A reboot of the PFSense box clears the issue. Clearing the state tables doesn't. There is nothing untoward on the PFSense box (alarms/alerts or odd log entries).

I should say that the PFSense box is running on ESXi on an HPO Proliant.