ASR-1001 64-bit counters for virtual-access interfaces

[modesto916]

Hello,

We need 64-bit counters (ifHCInOctets / ifHCOutOctets) for virtual-access (PPPoE) interfaces. We would like to use this to store historical subscriber traffic-rates for at least a week. We did some tests and it seems that the device only keeps 32-bit counters for this type of interface:

modesto@localhost:~ # snmpbulkwalk -v 2c -c 'myCommunity' 192.168.0.100 'IF-MIB::ifInOctets.1612'
IF-MIB::ifInOctets.1612 = Counter32: 2030075411
modesto@localhost:~ # snmpbulkwalk -v 2c -c 'myCommunity' 192.168.0.100 'IF-MIB::ifHCInOctets.1612'
IF-MIB::ifHCInOctets.1612 = No Such Instance currently exists at this OID

In the example above the Virtual-Access belongs to a PPPoE subscriber.

Do you know if it is possible to change this behaviour changing the some configuration parameter?

[Flavio Miranda]

Hi

 Do you refer to change this:

IF-MIB::ifInOctets.1612 = Counter32: 2030075411

To this:

IF-MIB::ifInOctets.1612 = Counter64: 2030075411 ?

There is an explanation here about it. But, it seems to me that this is about code. I dont think this can be change.

https://www.cisco.com/c/en/us/support/docs/ip/simple-network-management-protocol-snmp/26007-faq-snmpcounter.html 

[Georg Pauwen]

Hello,

the OIDs are:

1.3.6.1.2.1.31.1.1.1.6 ifHCInOctets

1.3.6.1.2.1.31.1.1.1.10 ifHCOutOctets

So it looks like you are polling the correct ones.

I found a forum post where somebody is using CACTI, and there seems to be a template for Cisco routers that polls 64-bit counters. Unclear if that works for virtual access interfaces...

https://forums.cacti.net/viewtopic.php?t=55291

[modesto916]

Hi,

That's correct, those are the OIDs I am polling. I can only see 64 bit counters for physical interfaces (gigabit, ten gigabit, etc). It seems that IOS does not keep 64 bit counters for virtual access interfaces, at least by default.

I am trying to find another OID that keeps those counters, even if it is Cisco specific, but so far I found nothing.

Thanks.

[Georg Pauwen]

Hello,

I did some more research, and I think the reason is that virtual access interfaces are not considered 'high speed':

'For interfaces that operate at 20,000,000 (20 million) bits per second or less, you must use 32-bit byte and packet counters. For interfaces that operate faster than 20 million bits per second, and slower than 650,000,000 bits per second, you must use 32-bit packet counters and 64-bit octet counters. For interfaces that operate at 650,000,000 bits/second or faster, 64-bit packet and octet counters must be used.'

'Correspondingly, Cisco IOS® Software does not support 64-bit counters for interface speeds of less than 20 Mbps. This means that 64-bit counters are not supported on 10 Mb Ethernet ports, only 100 Mb Fast-Ethernet and other high speed ports support 64-bit counters.'

[modesto916]

Hello,

Thanks for trying to help, I haven't found a solution for this yet. I think we will have to stick with accounting data until we find some OID that provides those counters in realtime.