RMON + SNMP stats on a Fasthub 440: polling the appropiate values?

josevnz · ‎05-29-2002

Greetings --moderator edit--,

As fas as i know a RMON monitored device should have a "probe" per each interface you want to monitor (for example if you have a 24 port switch then you should be able to gather run a probe on each one of the 24 ports); But my Cisco FastHub 440 only shows 2 interfaces in the 'etherStatsIndex' (.1.3.6.1.2.1.16.1.1.1.1.xx) even if the Hub have 24 ports (ifNumber, .1.3.6.1.2.1.2.1.0).

But gets more weird :). If you look at the interface descriptions and speeds you will see the following:

(Descriptions, i picked the interfaces 1 and 2)

ifDescr.1 = "Agent's 100Mbps Ethernet NIC Interface"

ifDescr.2 = "Agent's 10Mbps Ethernet NIC Interface"

ifDescr.3 = "Common 100Mbps Backplane"

ifDescr.4 = "Common 10Mbps Backplane"

ifDescr.5 = "Unit 1, 100Mbps Micro-isolated Segment"

ifDescr.6 = "Unit 1, 10Mbps Micro-isolated Segment"

ifDescr.7 = "Unit 1, Extension Module Uplink Segment"

ifDescr.8 = "Unit 2, 100Mbps Micro-isolated Segment"

ifDescr.9 = "Unit 2, 10Mbps Micro-isolated Segment"

ifDescr.10 = "Unit 2, Extension Module Uplink Segment"

ifDescr.11 = "Unit 3, 100Mbps Micro-isolated Segment"

ifDescr.12 = "Unit 3, 10Mbps Micro-isolated Segment"

ifDescr.13 = "Unit 3, Extension Module Uplink Segment"

ifDescr.14 = "Unit 4, 100Mbps Micro-isolated Segment"

ifDescr.15 = "Unit 4, 10Mbps Micro-isolated Segment"

ifDescr.16 = "Unit 4, Extension Module Uplink Segment"

And the speed:

ifSpeed.1 = Gauge32: 100000000

ifSpeed.2 = Gauge32: 10000000

ifSpeed.3 = Gauge32: 100000000

ifSpeed.4 = Gauge32: 10000000

ifSpeed.5 = Gauge32: 100000000

ifSpeed.6 = Gauge32: 10000000

ifSpeed.7 = Gauge32: 100000000

ifSpeed.8 = Gauge32: 100000000

ifSpeed.9 = Gauge32: 10000000

ifSpeed.10 = Gauge32: 100000000

ifSpeed.11 = Gauge32: 100000000

ifSpeed.12 = Gauge32: 10000000

ifSpeed.13 = Gauge32: 100000000

ifSpeed.14 = Gauge32: 100000000

ifSpeed.15 = Gauge32: 10000000

ifSpeed.16 = Gauge32: 100000000

Only interfaces 1 and 2 have stats, but #2 shows 10MB/sec speed and #1 shows 100Mb/sec (all our client workstations are using FastEthernet). Also the Cisco documentation doesn't talk about RMON on this hub (and the telnet / web interface doesn't show any command to customize it either).

So my questions are:

1) Wich interface i should monitor in this Hub and why i have only two

2) Why one of them is working at 10Mb/sec instead of 100Mb/sec.

3) The ifOperStatus OID shows than the 100Mb/sec interface is down but still got packets. How that can be possible?

Thanks in advance.

ciscomoderator · ‎06-05-2002

Since there has been no response to your post, it appears to be either too complex or too rare an issue for other forum members to assist you. If you don't get a suitable response to your post, you may wish to review our resources at the online Technical Assistance Center (http://www.cisco.com/tac) or speak with a TAC engineer. You can open a TAC case online at http://www.cisco.com/tac/caseopen

If anyone else in the forum has some advice, please reply to this thread.

Thank you for posting.

josevnz · ‎06-05-2002

Reading the documentation, i found that the "backplane" interface is the one i should monitor (shows the total capacity utilization of a given interface); Also there is a OID in the RMON that tells you which interfaces from the MIB2.interface MIB are beinng used in the monitoring:

.1.3.6.1.2.1.16.1.1.1.2.xx will give you:

etherStatsDataSource.1 = OID: ifIndex.3

etherStatsDataSource.2 = OID: ifIndex.4

And if you check the .1.3.6.1.2.1.2.2.1.2.xx OID you will get:

ifDescr.3 = "Common 100Mbps Backplane"

ifDescr.4 = "Common 10Mbps Backplane"

I guess that each backplane corresponds to the sum of all interfaces that are running at 10Mb/sec and 100Mb/sec.

JV.