SNMP Port Query

[marshyrob]

Hi All

Can any tell me if it is possible to send a SNMP query to a passport 8600 to obtain a given MAC addresses IP address.

So for example, i query a specific port with the relevant OID which includes the MAC address and the returned value is IP address of the device attached to that port.

I did find that it does IP - MAC when i walked it but couldnt find the option for MAC to IP. The OID and MIB for that were - IP-MIB (ipNetToMediaIfPhysAddress)

Any help or would be appreciated.

Rob

 

[anthonyanderberg]

I think I know what you're looking for, but let me know if I'm way off base here:
What I've had to do in the past is to walk the whole ipNetToMediaTable (.1.3.6.1.2.1.4.22.1) and stick it all in a hash that I can then use to find the IP-MAC pairs.
That along with the contents of the dot1dTpFdbTable (.1.3.6.1.2.1.17.4.3) allow me to find pretty much any device on our network.

 

[marshyrob]

Hi anthonyanderberg

Can you explain the hash process? This is what im looking for but not too sure what you mean about the hash bit.

Regards

Rob

 

[anthonyanderberg]

Sorry, I program in Perl and often assume everyone else does too - or at least I assume they should be using Perl.

A hash (sometimes called an associative array) is a data structure in Perl that allows me to stick the data in memory and then easily pull out the IP/MAC pair(s) I'm looking for.