Cisco 877 downstream 0 on ATM interface with high bw

[aaron465]

Hi there,

I am having a bit of a strange problem, and I just wanted to see if anybody had come across it before, and (ideally) find out how to fix it.

I have got cacti monitoring the ATM interface, as well as all four Ethernet interfaces on my Cisco 877 router. It all seems to work fine, apart from when there is a lot of bandwidth on the ATM interface (ie maxing out the line).

When the connection is maxed out, the 'inbound' line on the graph drops to 0, and stays there for the entire time. I am currently testing this by downloading some games on steam, and watching the graph.



As you can see from the image above, there is a short spike at the beginning, then the incoming bandwidth drops to 0, but the outgoing line carries on. Also interestingly the bandwidth shows up fine on the Ethernet interface I am connected to (and downloading from steam on). When there is less bandwidth on the ATM interface it is graphed perfectly.

Does anybody have any ideas?

Thanks,
Aaron

[rdobroun]

Hi,

have you tried to do a snmpwalk on the if counters...
that way you can easiely find out wheter the problem is cacti or route related...

just do a
snmpwalk -v2c -cWHATEVERCOMMUNITY .1.3.6.1.2.1.2.2.1.10
or
snmpwalk -v2c -cWHATEVERCOMMUNITY .1.3.6.1.2.1.2.2.1.16

if you do this a few times in a row you should see a counting up 32bit integer.

if the value remains the same or you experience a timeout the problem lies on the router...

[aaron465]

Hi there,

Thanks for the reply. I am not very familiar with SNMP, this is really my first experience with it (or at least with diagnosing it).

When I run those commands I get

Code: Select all

snmpwalk: Unknown host (.1.3.6.1.2.1.2.2.1.16) (Connection timed out)

How does it know what ip to talk to, is it part of the .1.3.... number? how do i find the correct number to use?

Thanks
Aaron

[TheWitness]

Smells like a timeout. Wait, just farted. Sorry.

TheWitness

[mcutting]

Smells like a timeout. Wait, just farted. Sorry.

TheWitness