Re: [ECOS] eCos MIB file?

[Hugo Tyson <hmt at redhat dot com>]

Andrew Lunn <andrew.lunn@ascom.ch> writes:
> Grant Edwards <grante@visi.com> wrote:
> > I'm not sure I understand your answer.  The C language source
> > files in the eCos source tree are generated from a specific set
> > of MIB files.  Where are those files located?  On your machine
> > where you packaged up the SNMP stuff or on my machine where I
> > build the SNMP stuff?

As Andrew rightly said, neither.  They're in the UCD web space somewhere,
and likely to be in your host's SNMP tools somewhere.  The eCos C language
source files are not regenerated as part of the build process; the build
process does not need to have the MIBs around.

Aside - the SNMP library (snmplib) has facilities for reading in and
parsing and building data structures based on all the MIBs it can find in
the local filesystem.  That's because it's shared between agent code (as in
eCos, the *managed* machine) and tools code (as in snmpwalk &c, management
tools, on your desktop machine).  But the agent code does not need to have
all that stuff available, so the eCos snmplib doesn't bother with all that.

> Nope. The MIB compiler can be used for generating template code to
> implement a MIB. You then have to fill in the real implementation for
> each variable. Thinks of the MIB compiler as a GUI builder. The GUI
> builder will give you the buttons, dialog boxes, scroll bars etc, you
> the programmer has to fill in the code which does the functionality
> behind the buttons. As with a GUI, you don't have to use the GUI
> builder, you can code everything by hand. Thats what happens with the
> MIBs eCos implements. The MIB compiler is there for users who want to
> add there own MIBs. 

Exactly.  (Or extend somehow the existing MIBs, perhaps)
  
> > I've got a customer who wants copies of the MIB files used by
> > the eCos SNMP agent, and at present I've no idea what files to

In a sense the eCos SNMP agent uses no MIB files because it's all hard
coded - but it supports host tools which use the MIB files as Andrew
describes.

> > give him.  I've got a set of 33 MIB files on my development
> > machine, but I don't know if those are the ones used by eCos.
> 
> What your customer wants is the textual description of the MIB to feed
> into his management station. The agent implements MibII and the 802.3
> MIB. MibII is the De facto standard so all management stations should
> already know about this. 802.3 is also a well known standard, also
> known as the EtherLike-MIB. Maybe his station does not know this one?
> In UCD its called EtherLike-MIB.txt. If all else fails, ask him for
> the OIDs he is having problems with. Its then easy to find the correct
> file.
> 
> My experience is that customers do not understand SNMP very well and
> so ask silly questions. Its worth spending a little time educating
> them, or pointing them towards a good book. 

Thanks Andrew, good of you to go into those details - I certainly couldn't
remember the right terminology off the top of my head!

	- Huge