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New Member

Cnr configuration in Docsis Network

Dear All,

I'm going to configure a CNR server for a Docsis network. My boss wants allocate IP address by Cnr in a static way, i.e. he wants allocate a small subnet to each customer, becasuse in this way we can manage QoS based on Ip subnet. How Can I do it by Cnr?

I suppose to configure a scope for each subnet, but I don't know if it is the correct way to do it, because we are expecting to reach 20K users, so I need to create 20k scope in Cnr.

Can someone help me?



Cisco Employee

Re: Cnr configuration in Docsis Network

Hi Paolo.

I'm not sure why you would want to do this? It seems you would be entirely defeating the purpose of having DHCP in the first place.

Sure, you could create 20,000 scopes, but wouldn't it be easier to just have a static IP address for each device if that was your desire?

Maybe I'm missing something with what you're trying to accomplish...perhaps you could explain with more detail?

Thanks and regards,


New Member

Re: Cnr configuration in Docsis Network

Hi Joe,

thank you very much for your reply. It is very interesting.

We are doing this kind of static assigmement because we want manage QoS based on /29 or /28 subnet. I suppose if we manage ip allocation with default DHCP behaviour, we need to insert QoS rules based on host ip address and this is not very good for the equipment we are going to use to do it. ( Allot NetEnforce )

And then, we want provisioning only cable modem, not the PC behind the modem.

I hope this brief explanation could be useful for you.

Regards Paolo

Cisco Employee

Re: Cnr configuration in Docsis Network

Hi Paolo,

I think you could likely use expressions and tags to do this but that's not likely to be the optimal way to go, since you still would be using 20,000 scopes for 20,000 clients, and this likely would result in a waste of at least that many addresses split-off into networks. Because of this, it just doesn't make a lot of technical or business sense. If you're just doing this for QOS, then config files and CMTS could possibly do the job? Maybe a cable expert could give some insight into that.



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