* Ted Unangst <[EMAIL PROTECTED]> [2006-03-08 23:28]: > On 3/8/06, Matt Rowley <[EMAIL PROTECTED]> wrote: > > > monitoring the congestion counter in pfctl -si helps a lot. > > > you don't want too long queues tho, that is contraproductive. > > What are the consequences of ifq set too large? > packets go in the queue and don't come out.
it is not that simple. first, it burns kernel memory. tho unless you set the queue length to totally insane high values that should not be much of an issue. then it can increase latency quite a bit. packets do not get dropped early enough but just sit in the queue. tcp relies on packets to be dropped to adjust to available bandwidth. last not least, it can prevent the congestion indicator to be set in time and thus hurt your machine badly. details about taht are on http://bulabula.org/papers/opencon05/mgp00027.html and following slides. there's more, but that should scare you enough :) -- BS Web Services, http://www.bsws.de/ OpenBSD-based Webhosting, Mail Services, Managed Servers, ... Unix is very simple, but it takes a genius to understand the simplicity. (Dennis Ritchie)
