pfSense

After restarting the UPnP service, I can type the following from my workstation `upnpc -r 1234 TCP` and I get the response:

List of UPNP devices found on the network :
desc: http://10.0.0.1:2189/rootDesc.xml
st: urn:schemas-upnp-org:device:InternetGatewayDevice:1

Found valid IGD : http://10.0.0.1:2189/ctl/IPConn
Local LAN ip address : 10.0.0.93
ExternalIPAddress = [redacted]
InternalIP:Port = 10.0.0.93:1234
external [redacted]:1234 TCP is redirected to internal 10.0.0.93:1234 (duration=0)

I can do this as many times as I like, but after ~5 minutes it stops responding:

No IGD UPnP Device found on the network !

The miniupnpd process is still running, and there is nothing in the log files.

When it's responding, running tcpdump on pfsense shows the following:

00:41:29.931828 IP 10.0.0.93.62316 > 239.255.255.250.ssdp: UDP, length 137
00:41:29.985376 IP router.home.arpa.ssdp > 10.0.0.93.62316: UDP, length 433

When it's not responding, the only thing I see is the occasional:

00:48:59.585197 IP router.home.arpa.42061 > 239.255.255.250.ssdp: UDP, length 473

I tired running miniupnpd in debug mode. It displays debug output indicating it is responding to my upnpc commands. But after ~5 minutes there is no longer any reaction to my commands, and no error messages or indications that the process has hung or crashed.