Q. Is there a workaround for probing equipment where the ifIndex values are out-of-order?

A. InterMapper stops scanning the ifTable when it detects an out-of-order ifIndex. It does this to prevent a loop, where an incorrect SNMP implementation could continually reply with the same set of ifIndex values.

We have run into some network equipment where the indices for the ifTable and related tables do not proceed in the usual strictly increasing fashion, jumping around instead. The 'ALLOW-LOOPS' flag can be added in the flags = section of a custom SNMP probe header. Adding this flag to the header will instruct InterMapper to allow this situation.

Note: If the SNMP agent in your network device doesn't stop returning values when every item in the table has been read, then if this flag is set InterMapper will loop over the table continuously until 5000 reads have occurred, at which point it will stop.

Use of this flag is only supported in InterMapper version 5.0.6 and higher.