Dumb question: what are the numbers after some OIDs?

[schickman]

Hi, I frequently look up OIDs and see the prefix, e.g.
.1.3.6.1.2.1.17.4.3.1.1 and the description, in this case,
dot1dTpFdbAddress which gives the MAC address for which
a bridge has forwarding or filtering information.

But when I walk the actual device MIB for this OID I get:
.1.3.6.1.2.1.17.4.3.1.1.0.14.215.16.120.225 = 0xFFFFFFFFFFFF
where the FFs are replaced by a MAC address.
My question is; what does the OID suffix portion 14.215.16.120.225 signify?

Thanks, Bill

 

[bnorton916]

1.3.6.1.2.1.17.4.3.1.1 is the OID of the table.

How do you know which row in the table you are talking about? An index.

All tables have an index, it could be something arbitrary like "1" or "2" but usually it has meaning. It can be a simple number or something longer like an ipAddress.

It looks like dot1dTpFdbEntry has an index of dot1dTpFdbAddress,
which is an mac address(see below)

dot1dTpFdbEntry OBJECT-TYPE
SYNTAX Dot1dTpFdbEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION
"Information about a specific unicast MAC address for which the bridge has some forwarding and/or filtering information."
INDEX { dot1dTpFdbAddress }
::= { dot1dTpFdbTable 1 }

dot1dTpFdbAddress OBJECT-TYPE
SYNTAX MacAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION
"A unicast MAC address for which the bridge has forwarding and/or filtering information."


Hmmm... not sure if this makes sense.
Tables aren't always easy to explain...

Bill

 

[schickman]

Thanks Bill - I knew the 0 in .1.3.6.1.2.1.17.4.3.1.1.0
indicates that the switch knows about this MAC address but
does not have a specific port to associate it with -
and I can now see that the string 14.215.16.120.225 is a decimal
representation of the hex MAC address in the OID - they are
equivalent.

Regards,
Bill