view OID mask?
hi, are there any example illustrating the usage of the view OID mask? i have read the part of view directive in the snmpd.conf(5) and the vacmViewTreeFamilyMask definition in VACM rfc, but i can't understand it. thanks. -- Leo Lei 2006-09-20 - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Net-snmp-users mailing list Net-snmp-users@lists.sourceforge.net Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
Re: view OID mask?
On 20/09/06, Leo Lei [EMAIL PROTECTED] wrote: are there any example illustrating the usage of the view OID mask? i have read the part of view directive in the snmpd.conf(5) and the vacmViewTreeFamilyMask definition in VACM rfc, but i can't understand it. thanks. The latest version of the source (currently available as 5.4.pre1) has a re-written snmpd.conf(5) description of the view token, to expand on the role of the MASK field. This now reads as follows: view VNAME TYPE OID [MASK] defines a named view - a subset of the overall OID tree. This is most commonly a single subtree, but several view directives can be given with the same view name, to build up a more complex collection of OIDs. TYPE is either included or excluded, which can again define a more complex view (e.g by excluding certain sensitive objects from an otherwise accessible subtree). MASK is a list of hex octets (optionally separated by '.' or ':') with the set bits indicating which subidentifiers in the view OID to match against. If not specified, this defaults to matching the OID exactly (all bits set), thus defining a simple OID subtree. So: view iso1 included .iso 0xf0 view iso2 included .iso view iso3 included .iso.org.dod.mgmt 0xf0 would all define the same view, covering the whole of the 'iso(1)' subtree (with the third example ignoring the subidenti- fiers not covered by the mask). More usefully, the mask can be used to define a view covering a particular row (or rows) in a table, by matching against the appropriate table index value, but skipping the column subiden- tifier: view ifRow4 included .1.3.6.1.2.1.2.2.1.0.4 0xff:a0 Note that a mask longer than 8 bits must use ':' to separate the individual octets. Is that any more helpful? Dave - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Net-snmp-users mailing list Net-snmp-users@lists.sourceforge.net Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
Re: Re: view OID mask?
Dave Shield£º thank you! i had mistaken the word sub-identifier, for example, for view OID ifEntry, i had thought the sub-identifers is 1(ifIndex) - 22(ifSpecific) under ifEntry. === 2006-09-20 16:00:30 === view ifRow4 included .1.3.6.1.2.1.2.2.1.0.4 0xff:a0 for the latest 3 sub-identifiers, the corresponding bits can be 0010 or 1010 , so, the mask can be 0xff:a0 or 0xff:20; right? = = = = = = = = = = = = = = = = = = = = Leo Lei 2006-09-20 - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV___ Net-snmp-users mailing list Net-snmp-users@lists.sourceforge.net Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
Re: Re: view OID mask?
On 20/09/06, Leo Lei [EMAIL PROTECTED] wrote: i had mistaken the word sub-identifier, for example, for view OID ifEntry, i had thought the sub-identifers is 1(ifIndex) - 22(ifSpecific) under ifEntry. No - the term subidentifier refer to the individual numbers (or names) within an OID. So *each* of 1, 3, 6, 1, etc are subidentifiers. There is one particular subidentifier within an OID that will refer to the column object, but this is no more (and no less) a subidentifier than any of the others. view ifRow4 included .1.3.6.1.2.1.2.2.1.0.4 0xff:a0 for the latest 3 sub-identifiers, the corresponding bits can be 0010 or 1010 , so, the mask can be 0xff:a0 or 0xff:20; right? I don't fully understand what you're asking here, but your bit patterns don't look right. The idea of the ifRow4 view is to match any OID of the form .1.3.6.1.2.1.2.2.1.x.4 (ignoring the column subidentifier) i.e. the row with index '4'. Setting this against a bit pattern of the relevant subidentifiers gives: .1.3.6.1.2.1.2.2.1.0.4 1 1 1 1 1 1 1 1 1 0 1 0 0 0 0 0 = 0xff:a0 So the second octet of the mask is 0xa0 I don't know where you get 0x20 from, but it looks completely bogus. Dave - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Net-snmp-users mailing list Net-snmp-users@lists.sourceforge.net Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
Re: view OID mask?
Dave Shield£º === 2006-09-20 16:50:44 === The idea of the ifRow4 view is to match any OID of the form .1.3.6.1.2.1.2.2.1.x.4 (ignoring the column subidentifier) i.e. the row with index '4'. Setting this against a bit pattern of the relevant subidentifiers gives: .1.3.6.1.2.1.2.2.1.0.4 1 1 1 1 1 1 1 1 1 0 1 0 0 0 0 0 = 0xff:a0 So the second octet of the mask is 0xa0 for the sub-identifier ifTable.1, i think we can set the corresponding mask bit to 1(exact match) or 0(wildcard), cause it's the only mib node for administrative purpose under ifTable. so i get 0xff:a0 or 0xff:20 1 1 1 1 1 1 1 1 1 0 1 0 0 0 0 0 = 0xff:a0 1 1 1 1 1 1 1 1 0 0 1 0 0 0 0 0 = 0xff:20 = = = = = = = = = = = = = = = = = = = = Leo Lei 2006-09-20 - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV___ Net-snmp-users mailing list Net-snmp-users@lists.sourceforge.net Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
Re: view OID mask?
On 20/09/06, Leo Lei [EMAIL PROTECTED] wrote: for the sub-identifier ifTable.1, i think we can set the corresponding mask bit to 1(exact match) or 0(wildcard), cause it's the only mib node for administrative purpose under ifTable. so i get 0xff:a0 or 0xff:20 1 1 1 1 1 1 1 1 1 0 1 0 0 0 0 0 = 0xff:a0 1 1 1 1 1 1 1 1 0 0 1 0 0 0 0 0 = 0xff:20 OK - I see what you mean. Yes, you could do that. It's somewhat counter-intuitive, completely unnecessary and likely to cause confusion, but it should work. By the same argument, you could probably omit most of the high-end mask bits as well, since all management information tends to be sited under .1.3.6.1 etc But I wouldn't advise doing that either. I am a Bear of Very Little Brain, and Prefer to Keep Things Simple. :-) Dave - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Net-snmp-users mailing list Net-snmp-users@lists.sourceforge.net Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
Re: Re: view OID mask?
On Wed, Sep 20, 2006 at 09:50:50AM +0100, Dave Shield wrote: On 20/09/06, Leo Lei [EMAIL PROTECTED] wrote: The idea of the ifRow4 view is to match any OID of the form .1.3.6.1.2.1.2.2.1.x.4 (ignoring the column subidentifier) i.e. the row with index '4'. Setting this against a bit pattern of the relevant subidentifiers gives: .1.3.6.1.2.1.2.2.1.0.4 1 1 1 1 1 1 1 1 1 0 1 0 0 0 0 0 = 0xff:a0 So the second octet of the mask is 0xa0 I don't know where you get 0x20 from, but it looks completely bogus. Dave, I was scratching my head until I saw the text above. I think putting the example and explantion above in the man page would make it much clearer. -- -- rouilj John Rouillard System Administrator Renesys Corporation 603-643-9300 x 111 - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Net-snmp-users mailing list Net-snmp-users@lists.sourceforge.net Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
Re: Re: view OID mask?
On 20/09/06, John Rouillard [EMAIL PROTECTED] wrote: I was scratching my head until I saw the text above. Even with the newer man page text (as quoted earlier in this thread) ? Oh :-( I think putting the example and explantion above in the man page would make it much clearer. Fair enough. I'll do that then. Dave - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Net-snmp-users mailing list Net-snmp-users@lists.sourceforge.net Please see the following page to unsubscribe or change other options: https://lists.sourceforge.net/lists/listinfo/net-snmp-users
