DHCP Stops working

Stewart

I have a site where DHCP stops working. Only about 10-15 devices total including PCs, tablets, printers, Sonos, etc. Logs show:

Feb 9 09:21:00 	dhcpd 	30460 	dhcp.c:4164: Failed to send 300 byte long packet over igb2 interface.
Feb 9 09:21:00 	dhcpd 	30460 	send_packet: No buffer space available
Feb 9 09:21:00 	dhcpd 	30460 	DHCPOFFER on 192.168.1.181 to 00:18:61:25:5a:9d via igb2
Feb 9 09:20:59 	dhcpd 	30460 	DHCPDISCOVER from 00:18:61:25:5a:9d via igb2
Feb 9 09:20:57 	dhcpd 	30460 	dhcp.c:4164: Failed to send 300 byte long packet over igb2 interface.
Feb 9 09:20:57 	dhcpd 	30460 	send_packet: No buffer space available
Feb 9 09:20:57 	dhcpd 	30460 	DHCPOFFER on 192.168.1.180 to 00:18:61:25:5a:9d via igb2
Feb 9 09:20:56 	dhcpd 	30460 	DHCPDISCOVER from 00:18:61:25:5a:9d via igb2
Feb 9 09:20:54 	dhcpd 	30460 	dhcp.c:4164: Failed to send 300 byte long packet over igb2 interface.
Feb 9 09:20:54 	dhcpd 	30460 	send_packet: No buffer space available
Feb 9 09:20:54 	dhcpd 	30460 	DHCPOFFER on 192.168.1.179 to 00:18:61:25:5a:9d via igb2
Feb 9 09:20:53 	dhcpd 	30460 	DHCPDISCOVER from 00:18:61:25:5a:9d via igb2
Feb 9 09:20:51 	dhcpd 	30460 	dhcp.c:4164: Failed to send 300 byte long packet over igb2 interface.
Feb 9 09:20:51 	dhcpd 	30460 	send_packet: No buffer space available
Feb 9 09:20:51 	dhcpd 	30460 	DHCPOFFER on 192.168.1.178 to 00:18:61:25:5a:9d via igb2

netstat -m shows

13951/3014/16965 mbufs in use (current/cache/total)
9727/1313/11040/1000000 mbuf clusters in use (current/cache/total/max)
1024/1253 mbuf+clusters out of packet secondary zone in use (current/cache)
0/93/93/524288 4k (page size) jumbo clusters in use (current/cache/total/max)
0/0/0/524288 9k jumbo clusters in use (current/cache/total/max)
0/0/0/20738 16k jumbo clusters in use (current/cache/total/max)
22941K/3751K/26693K bytes allocated to network (current/cache/total)
0/0/0 requests for mbufs denied (mbufs/clusters/mbuf+clusters)
0/0/0 requests for mbufs delayed (mbufs/clusters/mbuf+clusters)
0/0/0 requests for jumbo clusters delayed (4k/9k/16k)
0/0/0 requests for jumbo clusters denied (4k/9k/16k)
0 sendfile syscalls
0 sendfile syscalls completed without I/O request
0 requests for I/O initiated by sendfile
0 pages read by sendfile as part of a request
0 pages were valid at time of a sendfile request
0 pages were valid and substituted to bogus page
0 pages were requested for read ahead by applications
0 pages were read ahead by sendfile
0 times sendfile encountered an already busy page
0 requests for sfbufs denied
0 requests for sfbufs delayed

Version is pfSense 2.5.2-RELEASE (amd64)

I've searched and found this issue mentioned but haven't found real troubleshooting or solutions. Restarting the DHCPd service doesn't help but restarting the router does. Any advice on how to troubleshoot?

mer

When you say "restart the router" you mean "restart the pfSense device" or something else?
Have you physically unplugged/replugged the cable going to the igb2 interface?
My reason for asking is you say restarting DHCP service doesn't affect it, so perhaps something wedging at the device/device driver level.

Have you tried ifdown/ifup on igb2?

Stewart

@mer "Restarting the router" means that I rebooted the pfSense firewall. I didn't unplug/replug the cable or do the ifdown/ifup. I can see the packets coming in, it's just that the DHCP service wasn't working. Maybe if it happens again I can try that. I was trying to find one of those circling arrows that shows up throughout the interface to restart the NIC but didn't see it so I just rebooted the whole thing.