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Conference azur::mcc

Title:DECmcc user notes file. Does not replace IPMT.
Notice:Use IPMT for problems. Newsletter location in note 6187
Moderator:TAEC::BEROUD
Created:Mon Aug 21 1989
Last Modified:Wed Jun 04 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:6497
Total number of notes:27359

3242.0. "Strange behaviour with UCX Bind resolver enabled" by ZUR01::FUEGLISTER (Roland Fueglister, 760-2498) Wed Jun 24 1992 16:33

DECmcc commands like "Ping"  seem to use the Bind resolver, even if there is
nothing to resolve.
Can somebody explain, in which case, DECmcc is using the Bind resolver.

I have seen the following behaviour: 

VMS/UCX Bind resolver enabled

UCX> LOOP IpAddress --> echo comes immediately back
MCC> TEST SNMP IpAddress --> echo needs about one minute


VMS/UCX Bind resolver disabled

UCX> LOOP IpAddress --> echo comes immediately back
MCC> TEST SNMP IpAddress --> echo comes immediately back


				Regards,

				Roland
T.RTitleUserPersonal
Name		DateLines
3242.1Looks like a UCX problemYAHEY::BOSEThu Jun 25 1992 13:3111
	The SNMP AM makes a high level 'gethostbyaddr' call which is resolved
	by UCX. UCX determines where to look for the host information. Normally,
	it should look in the local host database and if it could not find
	the information, then only should it try accessing the BIND
	server.

	This problem has been mentioned by some other people. Hopefully,
	the UCX folks will have this problem fixed in their next release.

	Rahul.
3242.2TOOK::SWISTJim Swist LKG2-2/T2 DTN 226-7102Thu Jun 25 1992 15:425
    I don't know how this works on UCX, but on real Ultrix or OSF/1 systems
    the search order is user settable via parameters in file /etc/svc.conf.
    It is perfectly possible to specify bind then local as a search order
    even though local,bind is more typical.   Is this adjustable with UCX?
3242.3When is the 'gethostbyaddr' call invoked by the SNMP AM ?ZUR01::FUEGLISTERRoland Fueglister, 760-2498Fri Jun 26 1992 11:3928
I used the following register command to register my SNMP entity with Bind
Resolver disabled and a empty local host database, i.e. I have no registered
IpName in the local MIR. 

MCC> REGISTER SNMP fullname ADDRESS IpAddress

I disabled the Bind Resolver during the registration process, because the Bind
Server has no entry for my SNMP entity.

Then I enabled Bind Resolver and did the following command:

MCC> TEST SNMP IpAddress 


If I understand reply .1 correctly, the SNMP AM does a 'gethostbyaddr' call
each time there is a SNMP directive like REGISTER, TEST, SHOW, SET etc. 
Does the above mcc "Ping" command invoke the ucx bind resolver?

I understand, why the SNMP AM does a 'gethostbyaddress' call  during the
registration process.
What I don't understand at all, why the SNMP AM also should do a 'gethostbyaddr'
call after the entity is registered, i.e. has a registered fullname and an
IpAddress.


				Regards,

				Roland
3242.4YAHEY::BOSEFri Jun 26 1992 19:3528
	
	RE -1

>>If I understand reply .1 correctly, the SNMP AM does a 'gethostbyaddr' call
>>each time there is a SNMP directive like REGISTER, TEST, SHOW, SET etc. 
>>Does the above mcc "Ping" command invoke the ucx bind resolver?

>>I understand, why the SNMP AM does a 'gethostbyaddress' call  during the
>>registration process.
>>What I don't understand at all, why the SNMP AM also should do a 'gethostbyaddr'
>>call after the entity is registered, i.e. has a registered fullname and an
>>IpAddress.

	Whenever an IPAddress is specified in the TEST,SHOW, and SET commands,
	the SNMP AM does a gethostbyaddress to resolve the host name. This is
	done in a common initialization phase, although it may be argued
	that the host name is not used at all and hence, need not be resolved.
	It is true that the information is also stored in the name space for
	a registered entity, but we end up looking for it in the Domain
	Name Server. 

	The question is why should UCX look for the information in the BIND
	server if it is present in the local host database?  However, if 
	there is no entry at all for a particular host, a gethostbyaddress
	will cause UCX to always go to the BIND server, since an entry will
	not be found in the local database.

	Rahul.