On Thu, Feb 01, 2007 at 09:32:17AM +0100, Federico Giannici wrote: > Claudio Jeker wrote: > >On Wed, Jan 31, 2007 at 06:21:57PM +0100, Adriaan wrote: > >>On 1/31/07, Bret Lambert <[EMAIL PROTECTED]> wrote: > >>[snip] > >>>Running and tuning OpenBSD network servers > >>>in a production environment: > >>> > >>>http://www.openbsd.org/papers/tuning-openbsd.ps > >>> > >>>may have the info you're looking for. > >>IIRC Theo said he would throw Henning in the ocean for that paper ;) > >> > > > >Actually Henning said he would throw Henning in the ocean for that paper. > > > >But back to the original problem with the no buffer space reports. > >This is in fact an expected behaviour for non stream oriented protocols > >like udp or icmp (ping). The problem here is that ENOBUF is returned by > >the queuing code when the interface queue is full. The error is then > >reported upwards and in case of datagram sockets is reported back to the > >userland process. A smart client/server would reduce the packet throughput > >in such a case. e.g. ping -f is not that smart. > >In TCP this error is handled by the kernel and so mostly invisible for the > >userland. > > Claudio, thanks for the explanation. > > Considering that the traffic is not GENERATED by the PC itself, and that > it is a firewall/queuing/gateway with a lot of queues and traffic, how > can I increase the "interface queue"? > > Are we talking about a NIC (hardware) queue, so I can try to change it > with another model (currently a fxp)? > Or is it some kind of kernel buffer, so there is some kernel option to > increase? >
You are using many altq queues. Now altq implements a virtual limit on the interface queue via some sort of token bucket. If the queue gets full packet need to be dropped -- like stuffing 10Mbps into a 2Mbps queue will not work without dropping at least some packets. Altq returns ENOBUF when packets need to be dropped because the limit has been reached. So when your pfctl -v -s q output shows many dropped packets you know where the ENOBUFs come from. -- :wq Claudio
