[tcpm] WGLC: TCP's Reaction to Soft Errors
Gorry Fairhurst <gf@erg.abdn.ac.uk> Fri, 27 April 2007 07:34 UTC
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Date: Fri, 27 Apr 2007 08:33:31 +0100
From: Gorry Fairhurst <gf@erg.abdn.ac.uk>
Organization: University of Aberdeen, UK
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Cc: Gorry Fairhurst <gorry@erg.abdn.ac.uk>, Ted Faber <faber@ISI.EDU>, "mallman@icir.org" <mallman@icir.org>
Subject: [tcpm] WGLC: TCP's Reaction to Soft Errors
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Review of: draft-ietf-tcpm-tcp-soft-errors-05.txt I think this documents an important issue that has been around for some time and would like to support this progression for publication as an informational RFC. It is disappointing that the IETF could not reach consensus on this issue (I would have liked to have seen that happen), notwithstanding this, it seem to me to be very worthwhile to document what is implemented and offer guidance that relates it to existing specifications. IMHO, we should publish this. Best wishes, Gorry --- Questions: 1) What happens if the SYN segment contains IP or TCP options that a middlebox rejects (and issues an ICMP error code)... if we take the variation of the algorithm, does it imply the sender tries a new IP address, or that it retries with a different option combination? Are there any side effects from this? 2) Normally TCP backs off its timer each SYN it sends for the same connection. Does this imply that the sender still backs-off the timeout value when it retries with a different IP address, or does it just start with the initial time-out value? - In cases where there is congestion or very long network path delays this could impact stability? or even prevent setting up the connection is specific topologies? 3) I do not understand this sentence, can you clarify?: /([Shneiderman] and [Thadani] offer some insight into the interactive systems)./ Editorial comments: ------------ - the abstract is hard to parse: " This document describes a non-standard, but widely implemented, modification to TCP's handling of ICMP soft error messages received in any of the non-synchronized states, that rejects connections experiencing those errors immediately. " I find the first line of abstract a little hard to unravel. The problem part is /that rejects connections experiencing those errors immediately/ " This document describes a non-standard, but widely implemented, modification to TCP's handling of ICMP soft error messages. This immediately rejects connections that receive soft errors in any non-synchronized state. ------------ Section 2 --- Suggest change: /Even though ICMPv6 didn't/ to /Even though ICMPv6 did not/ --- /one could extrapolate the concept of soft errors to ICMPv6/ ^ - Insert a reference - to RFC2463? --- Suggest change: / that's not signaled / to / that is not signaled / --- /to corresponding TCP instance/ ^ - Insert "the" --- Suggest change: /won't change in/ to /will not change in/ --- Suggest change: / before trying alternate addresses./ to / before trying an alternate address./ --- Suggest change: / A particular scenario in which the above sketched type of problem may occur regularly is that where dual stack nodes that have IPv6 enabled by default are deployed in IPv4 or mixed IPv4 and IPv6 environments, and the IPv6 connectivity is non-existent/ to / Dual stack nodes represent a case where the type of problem outlined above may regularly occur. This arise when a dual stack node with IPv6 enabled by default is deployed in an IPv4 or a mixed IPv4 and IPv6 environments, and the IPv6 connectivity is non-existent./ --- /Unreachability Detection (NUD)/ ^ - Insert reference. --- Section 6.1 /IP addresses in the list/ ^^^^^^^^^^ - The list has not been mentioned previously in this section. ----- Suggest change: /attack---even if only slightly/ to: /attack, even if only slightly/ --- The suggestion of making a table in section 2, noting the set of error codes in IPv4 and IPv6 ICMP messages seems a usrful additional, which I would encourage. --- Finally in rev-03, I commented that "I see this document is INFO - yet it seems to include an RFC2119 declaration, and does not use keywords." I was concerned that the document did NOT make BCP-Style recommendations. However, I now realise that you do cite keywords, which presumably should be interpretted as per RFC2119. A note to this effect would be OK. (I'm confessing that I may have previously given you wrong advice). _______________________________________________ tcpm mailing list tcpm@ietf.org https://www1.ietf.org/mailman/listinfo/tcpm
- [tcpm] WGLC: TCP's Reaction to Soft Errors Ted Faber
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Ted Faber
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Arifumi Matsumoto
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Fernando Gont
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Arifumi Matsumoto
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Mark Allman
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Fernando Gont
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Carlos Pignataro
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Mark Allman
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Mark Allman
- [tcpm] WGLC: TCP's Reaction to Soft Errors Gorry Fairhurst
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Saikat Guha
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Fernando Gont
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Joe Touch
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Fernando Gont
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Joe Touch
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Joe Touch
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Saikat Guha
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Joe Touch
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Fernando Gont
- [tcpm] Timeliness requierments for ICMP Fernando Gont
- [tcpm] Re: Timeliness requierments for ICMP Joe Touch
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Saikat Guha
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Pasi Sarolahti
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Ted Faber
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Fernando Gont
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Joe Touch
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Ted Faber
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Ted Faber
- Re: [tcpm] WGLC: TCP's Reaction to Soft Errors Saikat Guha