re0 watchdog timeout and dhclient send_packet no buffer

[DannyBoy]

Hi guys

My server machine has been running 6.0 without problems for a good while until three days ago. Now I'm getting (so far) every 24 hours at around 19:50 GMT+2 this network error

re0: Watchdog timeout
dhclient: send_packet: No buffer space available

and my WAN connection drops. I can restore connection by running

sh /etc/netstart

but how do I figure out what the hell is causing the problem? I haven't changed any interface settings from defaults. This stuff just started to happen out of the blue.

I asked my ISP to bump up my network speed two weeks ago and it worked out just fine until now. Could this be related to the problem?

[jggimi]

Hello, and welcome!

A watchdog timeout occurs when a peripheral device -- such as a NIC -- does not respond to a command within a set time. Generally, they are caused by hardware issues: in this case the NIC or its physical media attachment.

I expect that running out of mbufs occurs because the device has stopped processing data. You can monitor mbuf utilization with netstat -s or -ss, but that may not be helpful if buffer saturation happens rapidly due to a hardware problem.

[DannyBoy]

Hi jggimi, and thanks!

What really struck me was that problem seems to be periodic. I attached file with output from netstat. I can't tell from it myself whether it's causing the problem or not, though

[jggimi]

I recently replaced an RJ45 connector on a cable. The problem was intermittent, and did not manifest as a watchdog timeout. But it manifested in different ways:

• Initially, the interface would just transition by itself from "up" to "down" - dhclient would then exit.
• The interface would just stop transmitting or receiving packets. The line would stay up and active.

I don't know if your problem is related to cable or connector, but it should be relatively easy to resolve if it the cable happens to be the root cause.

[DannyBoy]

It's definitely worth a try to switch the cable. If the problem occurs one more time, I'll do that. Thanks for advice!