Date: Sat, 17 Nov 2001 12:20:11 -0600 (CST) From: Jonathan Lemon <jlemon@flugsvamp.com> To: knmurthy30@hotmail.com, net@freebsd.org Subject: Re: TCP Fast Retransmit Message-ID: <200111171820.fAHIKBw94562@prism.flugsvamp.com> In-Reply-To: <local.mail.freebsd-net/F178MZMtjQ4S8Uq5nlh0000f0a7@hotmail.com>
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In article <local.mail.freebsd-net/F178MZMtjQ4S8Uq5nlh0000f0a7@hotmail.com> you write: >Hello, > >1. Is there any sysctl variable to control the number of >duplicate acks after which the sending TCP gets into a fast >retransmit mode? No, but the current limit is in tcp_input.c: static int tcprexmtthresh = 3; so you can easily change this. >2. If I have a switch that does not support any port aggregation, >and it is connected to a BSD machine with 2 ethernet NICs that have >identical MAC, will the switch forward *each* packet destined to the BSD >machine to both of the NICs. Unlikely. The switch will probably allow only one mac->port mapping. >3. Apart from using tcpdump, are there any other tools/ways to analyze the >dynamic behaviour of a BSD stack - like knowing when there have >been retransmits, the state of various buffers in the stack etc. I like tcptrace, but that is an external view. You could try turning on the TCPDEBUG #define, although I'm not sure how useful it would be. -- Jonathan To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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