HUM - Interface Utilization

[v.vasilev]

Hello!

I have my router forwarding packets at that speed:

30 second input rate 982418000 bits/sec, 91133 packets/sec

30 second output rate 982413000 bits/sec, 91130 packets/sec

However, HUM shows only 10% load on the link (I have around 936Mbit/s which should be around 93%)!

Regards,

Vladislav

[GRAEME DANIELSON]

I am on an eval of HUM and just noticed today I have the same problem. Did a search before posting and found your question, so I'll get in the queue.

I have two GbE interfaces back to back - one a 6500 Sup32 port, the other a 3750 port. While traffic is maxed out in one direction HUM never show more than about 7% util for both interfaces.

Sample "sh int" from the 3750 below, HUM graphs this as 5% RxUtil and also about 5% TxUtil

GigabitEthernet2/0/52 is up, line protocol is up (connected)

Hardware is Gigabit Ethernet, address is 0021.1bf1.2034 (bia 0021.1bf1.2034)

Description: CWDM-1490 Link to Prod via fibre

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,

reliability 255/255, txload 11/255, rxload 221/255

Encapsulation ARPA, loopback not set

Keepalive not set

Full-duplex, 1000Mb/s, link type is auto, media type is CWDM-1490 SFP

input flow-control is off, output flow-control is unsupported

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:33, output 00:00:07, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

30 second input rate 869991000 bits/sec, 99076 packets/sec

30 second output rate 44243000 bits/sec, 62783 packets/sec

5351330258 packets input, 5188871774044 bytes, 0 no buffer

Received 10773626 broadcasts (0 multicasts)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 4391875 multicast, 0 pause input

0 input packets with dribble condition detected

3101535098 packets output, 312164650488 bytes, 0 underruns

0 output errors, 0 collisions, 2 interface resets

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier, 0 PAUSE output

0 output buffer failures, 0 output buffers swapped out

Note that I have checked on a 2800 router Ethernet interface and HUM seems accurate for these.

[Joe Clarke]

Both of you are making a potentially erroneous calculation. This output shows a 30 second sample. HUM is most likely running a sample over 5 minutes. The 5 minute sample rate could potentially be much lower.

The easiest way to see what HUM is seeing is to get a sniffer trace filtering on udp/161 traffic to this device for a period of twice the HUM polling interval (e.g. 10 minutes if the polling interval is 5 minutes). This way, the math can be applied using the exact same data HUM is seeing.

It may also reveal the HUM is using the wrong objects to collect interface utilization.

[GRAEME DANIELSON]

I understand what you're saying but the two interfaces I described have been running at 90%+ for 4 hours and HUM still says <10%

Will go back and check the poller though see if I can see anything untoward there. As I said it looks correct for at least two other device's Ethernet interfaces I've bothered to check on.

[v.vasilev]

I've got this problem on SPA-2X1GE (SIP-400) and 7609 router. I am currently running some tests so the router has been forwarding at that rate for more than 24 hours now.

I haven't come across this problem with my other device being monitored by HUM - Catalyst 3750 and a Gigabit Ethernet uplink. Check out the screenshot.

Regards,

Vladislav

[Joe Clarke]

Again, the thing that's going to help identify the problem is the sniffer trace. This will rule out problems on the device side, and calculation problems on HUM's side.

[k.abillama]

Hi Guys, I have a similar issue, please let me know the results of this conversation, thx