Date: Sat, 30 Apr 2011 12:32:26 +0200 From: =?iso-8859-1?Q?Michael_T=FCxen?= <Michael.Tuexen@lurchi.franken.de> To: Schoch Christian <e0326715@student.tuwien.ac.at> Cc: freebsd-net@freebsd.org Subject: Re: [SCTP] ICMP unreachable message reenables data transmit Message-ID: <F4802366-A9B4-4515-8E6D-E5C80C06408B@lurchi.franken.de> In-Reply-To: <20110430121518.25761cpmtrp0jtpy@webmail.tuwien.ac.at> References: <20110430091148.31393q3py4j4bg38@webmail.tuwien.ac.at> <FD1FC82D-29D1-4186-A0AC-504653C28D85@lurchi.franken.de> <20110430121518.25761cpmtrp0jtpy@webmail.tuwien.ac.at>
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On Apr 30, 2011, at 12:15 PM, Schoch Christian wrote: >=20 > Zitat von Michael T=FCxen <Michael.Tuexen@lurchi.franken.de>: >=20 >> On Apr 30, 2011, at 9:11 AM, Schoch Christian wrote: >>=20 >>> During a measurement with CMT-SCTP and PF i figured out, that = sometimes a ICMP Destination unreachable message triggers a message = transmission on an inactive data path that has been primary before. >>>=20 >>> It looks as the ICMP message is reseting the inactive state back to = active without reseting RTO. >>>=20 >>> This behavior is triggered by a returning heartbeat message when no = ICMP unreachable by data is sent quite before. >>>=20 >>> Test system are two multi-homed hosts with FreeBSD8.1 and a WANem = host between. >>>=20 >>> A wireshark log can be provided on demand (quite large). >> Hi Christian, >>=20 >> any chance to upgrade the FreeBSD machines to head or to use newer >> SCTP sources, which I could provide? It would require a recompilation >> of the kernel... >=20 > It is possible, but the results could be provided not until next week > if a reboot is necessary. > I can use any sources you could provide me since nothing else is done = at this systems. OK, but maybe I can try to understand what is going on. How many paths do you have? One is inactive, but was primary, so it is confirmed. On another one, you get an ICMP (which one? Port = unreachable, host unreachable, ...). Do you have more than two paths? The ICMP message would not reset the RTO, since you need an ACKed TSN or a HB-ACK to to that. Since it is inactive, it is missing these. Sending on an inactive path is OK, as soon as you enter the dormant state, which means all your paths are inactive. Are you using the PF support for CMT? Best regards Michael >=20 >>=20 >> Are you using IPv4 or IPv6? >>=20 >=20 > IPv4 >=20 >=20 >> Best regards >> Michael >>>=20 >>> Regards, >>> Schoch Christian >>> _______________________________________________ >>> freebsd-net@freebsd.org mailing list >>> http://lists.freebsd.org/mailman/listinfo/freebsd-net >>> To unsubscribe, send any mail to = "freebsd-net-unsubscribe@freebsd.org" >>>=20 >>=20 >> _______________________________________________ >> freebsd-net@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-net >> To unsubscribe, send any mail to = "freebsd-net-unsubscribe@freebsd.org" >>=20 >=20 >=20
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