[j-nsp] EX2200 LLDP Port Info

[Saku Ytti]

Hey Bey and Bill,

> In fact, the behaviour of LLDP from platform to platform across the whole range is pretty inconsistent:

ACK.

> Anyway, you can partially resolve this issue with the following:
> set protocols lldp port-id-subtype interface-name

Yup.

<rant>
What is the purpose of LLDP? I feel the purpose is to allow programmatic
discovery of the network. Ignore rest, if I've understood incorrectly.

LLDP standard allows exactly one subtype for portID and chassisID, but allows
you to choose from list of several options, including 'locally defined' which
can contain anything, and you cannot a-priori know how to parse it.

None of the options available are 'SNMP ifIndex', which seems most apt, for
programmatic discovery of the network. Some vendors choose to send 'locally
defined' portID, which contains 'SNMP ifIndex'.

You can have 100% compliant LLDP implemention, which will give you no useful
information what-so-ever. Some of the rationale here seems to be flexiblity of
the standard. I wish there would be more stringent requirement, that if you
implement IP and SNMP, then you MUST send MGMT address as chassisID and you
MUST send ifIndex in portID and you MAY send other subtypes as needed.

Less lazy people might propose IEEE to do:

---
- addition of ifIndex to portID (8.5.3.2, table 8.3)
- addition of ifDescr to portID (8.5.3.2, table 8.3)
- networkAddress defined as address which must responds to SNMP, if
host implements SNMP (table 8.2)
- 1 or more chassisID, portID must be in PDU (8.5.2.4, 8.5.4.2)
- new section in (8.5.2.2, 8.5.3.2) where it is mandated if host
implements SNMP and IP (any version) it one of the subtypes in
chassisID must be 'networkAddress' and one of the subtypes in portID
must be ifIndex.
---
</rant>

-- 
  ++ytti