We have build up a test environment, where two FE interfaces (in and out) of a packet generator (smartbits) are connected to two corresponding ifs on the 7206. We have set up CBWFQ, based on DSCP-values generated by the packet generator.
When we use 128-byte packets, we see a drop rate of about 60-100% when bandwidth utilization (generated by smartbits) goes beyond 50%. When we use 256-byte packets or higher the drop rate goes down to 0% and all traffic is forwarded.
With the small packets we can see a very high cpu utilization (up to 95%) where there is only 60% in peak using the bigger packets.
Is this a bug or a feature (means, limitation by hw;-). Thanks for feedback.
Thanks for the feedback. What do you mean with more information? Do i have to open a tac case or can we discuss this in the forum? If forum is o.k. because other people could be interested in the ongoing i would post some configuration infos in the next message.
yes, it is a 7206VXR with a NPE-400 and 256MB of RAM.
No, CEF is not disabled.
We have build up a class-map, which matches the dscp values generated by the packet generator. Those classes are build into an output policy, where we define bandwidth restrictions for the different classes. Also we have defined a 100% max-reserved-bandwidth on the output interface.
So, we use CBWFQ as a queuing mechanism - and the 'sh policy-map'-command tells us, everything is fine configured.
As i have said, there is no problem (means, no drops) when we use >=256byte packets. When we use packets <=128byte there are drop rates at about 70-80%!
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.