Date: Wed, 17 Apr 2002 20:27:57 -0500 (CDT) From: Mike Silbersack <silby@silby.com> To: Bill Fenner <fenner@research.att.com> Cc: freebsd-net@FreeBSD.ORG Subject: Re: What does FreeBSD do when listen queue is full ? Message-ID: <20020417201853.C16380-100000@patrocles.silby.com> In-Reply-To: <200204171909.MAA01611@windsor.research.att.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, 17 Apr 2002, Bill Fenner wrote: > Boy, I hope not. Incoming SYNs should be ignored if the backlog > is met, so that the client can retransmit them. I know Microsoft > decided to use RST as a "my queue is full" indicator, but I hope > we're not following in their footsteps!... > > Bill Actually, I read the code slightly wrong. We don't send a RST, we just silently drop the connection. However, at the point we're talking about, we're already past the 3-way handshake, so either way the connection has been lost. Heh, actually, I take that back. With a syncookie, a retransmitted ACK should end up reestablishing the connection. Clever... I think that you're referring to the case where we receive an initial SYN, and the listen queue is full. With the syncache/syncookies, this is no longer a problem; either a syn cookie is returned, or the syn is silently dropped (depending on whether or not syn cookies are enabled.) With the pre-syncache code, yes, a RST was sent at that time. Mike "Silby" Silbersack To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20020417201853.C16380-100000>