Re: [nv-l] Discovery Loopback Interfaces

["Bill Evans" <wvevans@nc.rr.com>]

Martina Haseneder appended the following: 

      
Hi folks, 

in NV 5.1. you could switch the discovery of Loopback Interfaces off (netmon configuration). 
In NV 7.1. I don't find this possibility.

Do anybody know a solution?

Ciao
Martina Haseneder

NV 7.1. on AIX 4.3.3

I haven't seen anything to follow up your query during the last couple days so I clipped this from the NetView Version 6.0 Release Notes.  You evidently got caught way behind the release curve if you were still on Version 5.1.  Handling the situation in 7.1 depends on what you mean by "solution".  There has been a lot of discussion on this mailing list about loopback interfaces.  The general summary seems to be

1. Define your routers to DNS or in the /etc/hosts file with the loopback interface as the primary one to use.
2. Define all other interfaces as having the same name as the loopback.
3. NetView will then create one ICON for the router and locate the router by the one address reachable by all the other interfaces when a gethostbyaddress is executed. 

There is a second school of opinion which wants each interface named differently.  I believe that results is less than optimal performance by NetView and a much more complex network map but that's for each of us to decide.

 

The clipping from the NV 6.0 Release Notes explains the rationale of the removal of that switch:

Discovery of Loopback Interface

The ability to disable discovery of software Loopback interfaces hasbeen removed. The special loopback 127.0.0.1 is not affected and continues to be ignored. Software Loopback interfaces often have network masks of 255.255.255.255 and these were not handled consistently in previous versions of Tivoli NetView, hence the existence of the switch.

For Version 6.0, these interfaces and network masks are handled appropriately, making the Discover Loopback Interfaces switch for netmon (-L) obsolete.

I hope this sheds some insight on the question.  Look in the archives beginning along about last September 11 for the discussion on "DNS and NetView" for details on the discussion. (I'm afraid lot's of people missed the discussions of that week six months ago we will not soon forget.   May our collegues lost that week rest in peace.) 

 

Bill Evans  --  Consultant in Enterprise Systems Management
reply-to: wvevans@prodigy.net