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Static IP with docsis server

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omadon
Static IP with docsis server

My current configuration of docsis server is dynamic address assignment. Addresses are dynamically assigned and they are valid for one day. How to force static ip address assignment for CPE one certain cable modem.

So, I want that CPE on modem with ip address 10.0.1.100 allways gets same ip address specified somewhere in database.

Anonymous (not verified)
Static IP with docsis server

It`s very easy.
As you know - dhcp work in 2 ways:
1. dynamic assigning. When IP address leases dynamically, and every time it can be different.
2. static assigning. When you assign static IP for specific MAC-address. After that, every time then host with specific MAC request IP from dhcp-server, it`s always receive the same IP.

and the last, third way - no to tie IP address to MAC address (because there is a possibility to spoof the MAC address) and use PPPoE. In this way, you assign static IP address to specific login/password.

You you can choose any method.

Anonymous (not verified)
PPPoE

boombastic wrote:and the last, third way - no to tie IP address to MAC address (because there is a possibility to spoof the MAC address) and use PPPoE. In this way, you assign static IP address to specific login/password.
You you can choose any method.

Is this tested? I understood that strictly speaking PPPoE is a 'PPPoEoA' which means, that there is an ATM-network expected as backbone (or collapsed backbone)..

omadon
Static IP with docsis server

I solved this with pppoe, but I had to put access list on modem to prevent CPE to get address from dhcp also.

But i would still like to know is it possible to set static ip with docsis_server
and how to configure it (do i need separate pool? where to put CPE mac address and ip address?)

pppoe requires additional resources which in large amount require aditional licenses and I also get lower mtu problem. So for me if I don't need traffic accounting pppoe is a additional burden.

Anonymous (not verified)
Static IP with docsis server

In my network, I use DHCP server static IP solution... or Set the default lease time to 7 days or above...

Anonymous (not verified)
Static IP with docsis server

Quote:
Is this tested? I understood that strictly speaking PPPoE is a 'PPPoEoA' which means, that there is an ATM-network expected as backbone (or collapsed backbone)..

Yes it works perfectly in our ADSL ISP (www.tomsknet.ru). Any user obtain the same IP after establishing PPPoE session.
Talking about PPPoE & PPPoEoA, afaik PPPoE means PPPoE (in our city), I meant that DSLAM have FE ports towards BRAS (Cisco 7200, 7300) so it is pure Ethernet backbone.

Talking about Subj, we use so-called plain IP - DHCPD with static IP assign (same as chipip_chen).

Anonymous (not verified)
Static IP with docsis server

omadon wrote:I solved this with pppoe, but I had to put access list on modem to prevent CPE to get address from dhcp also.

But i would still like to know is it possible to set static ip with docsis_server
and how to configure it (do i need separate pool? where to put CPE mac address and ip address?)

pppoe requires additional resources which in large amount require aditional licenses and I also get lower mtu problem. So for me if I don't need traffic accounting pppoe is a additional burden.

I just had a short look on this piece of software. It seems that the only possibility to get static IP is to setup the CPE as CM because there the software is offering an static IP entry. It shouldn't make any difference if you're using another IP range than for the CM because normally a MAC-entry precedes all other rules. Maybe you should ask the author via email.

PPPoE: Here in Germany PPPoE is no problem and well known because most of the broadband connections are ADSL. Meanwhile MTU-problems usually are fixed by hacks like tcp-mss and CPE-routers that can deal these problems are wide spread. I wonder if PPPoE could offer possibilities in direction of QoS by assigning IP-ranges and using traffic shaping on OSS-hosts. This might be a solution for small cable networks where cable provider couldn't afford a big Cisco machine being able to run VLANs and where a expensive high bandwidth connection to internet backbone is to expensive. Or they just tunnel the whole PPPoE-traffic to a major ISP which is doing the whole accounting and public internet address handling (DHCP, DNS, LIR)
Just an idea. ;-)