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Newsgroups: comp.protocols.nfs Path: sparky!uunet!cs.utexas.edu!asuvax!ncar!csn!news.den.mmc.com!pgl-devsvr.den.mmc.com!jzwiebel From: jzwiebel@pgl-devsvr.den.mmc.com (John Zwiebel 303-977-1480 jzwiebel@pgl-devsvr.den.mmc.com) Subject: Re: NFS corruption discovery Message-ID: <1992Aug20.172636.2169@den.mmc.com> Sender: news@den.mmc.com (News) Nntp-Posting-Host: 147.105.201.12 Organization: PAGE @ Martin-Marietta References: <1992Aug19.225010.18306@den.mmc.com> <1992Aug20.042224.11176@decuac.dec.com> <k2.714296050@woodstock> Date: Thu, 20 Aug 1992 17:26:36 GMT Lines: 148 Everyone is right about the checksumming on AIX/NFS. The following APAR (which we are installing) is suppose to take care of it. Also the SUN implementation of NFS does not have the checksum turned on. If anyone is interested I can try to get the fix for that and post it. There is a kernel variable that you have to turn on. I'm still interested in someone confirming that they also see data corruption when crossing a cisco router and how often that corruption occurs. Whether they are running ARPA (standard DIX) or SNAP(802.3). Please send Email This is for current AIX/6000; I'm pursuing some more...: APAR Identifier ...... IX24569 Last Changed ........ 92/03/12 UDP/IP CHECKSUMMING FOR NFS MUST BE TURN ON. AND WE SHOULD ALLOW SYSTEM ADMINISTRATORS TO ALTER THIS DEFAULT. Symptom ...... NF CONFIG Status ........... CLOSED PER Severity ................... 3 Date Closed ......... 92/03/12 Component .......... 575603001 Duplicate of ......... Reported Release ......... 315 Fixed Release ............ 999 Component Name AIX V3 FOR RS/6 Special Types .... PE PTF List: PTF List: Release 315 : No PTF planned Release 320 : No PTF planned Parent APAR: Child APAR list: ERROR DESCRIPTION: Based on RFC 1122: "A host MUST implement the facility to generate and validate UDP checksums. An application MAY optionally be able to control whether a UDP checksum will be generated, but it MUST default to checksumming on.", this APAR request three things, first we should change the default value for the UDP/IP checksumming option for NFS from FALSE to TRUE, second we should provide a way to allow system administrators to alter this option, and finally we should document well this choice to inform benchmarking people the effect on performance. LOCAL FIX: PROBLEM SUMMARY: The variable that controls UDP checksumming for NFS was set so checksumming was off. PROBLEM CONCLUSION: Changed the initial value of the variable so checksumming is on by default. . Code changes: com/lib/c/rpc/kudpfstsnd.c bos312 delta 1.12.1.1 . This is targeted for the 3.1 2010 update. TEMPORARY FIX: Obtain latest nfs.ext from emergency fix server. Fixname is nfsextfix. COMMENTS: MODULES/MACROS: NONE SRLS: NONE RTN CODES: CIRCUMVENTION: . MESSAGE TO SUBMITTER: I think this is for AIX/PC NFS package: APAR Identifier ...... IX24745 Last Changed ........ 92/03/27 USERS NEED A WAY TO INTERROGATE AND CHANGE THE CHECKSUMMING OF NFS UDP PACKETS. Symptom ...... NF CONFIG Status ........... CLOSED PER Severity ................... 3 Date Closed ......... 92/03/27 Component .......... 560126201 Duplicate of ......... Reported Release ......... 110 Fixed Release ............ 999 Component Name NETWORK FILE SY Special Types .... PE PTF List: PTF List: Release 110 : No PTF planned Release 110 : No PTF planned Parent APAR: Child APAR list: ERROR DESCRIPTION: We would like to have a way to turn OFF and to turn ON UDP checksumming for NFS. As mention in RFC 1122, the host should provide an utility to control whether a UDP checksum will be generated. Moreover UDP checksums are optionals by their definition. LOCAL FIX: PROBLEM SUMMARY: A method of interegating the NFS UDP checksum was needed. PROBLEM CONCLUSION: Modified an existing program to allow interegating the checksum and other NFS "options". This program is called nfso and works just like no. . This is targeted for the 3.1 2009 update. TEMPORARY FIX: Obtain the chnfsopt/lsnfsopt from level 2. COMMENTS: MODULES/MACROS: NONE SRLS: NONE RTN CODES: CIRCUMVENTION: Obtain temproary fix. MESSAGE TO SUBMITTER: