nanog mailing list archives

Re: Migrating from PPP to DHCPo82


From: Mike <mike-nanog () tiedyenetworks com>
Date: Mon, 08 Nov 2010 08:50:08 -0800

MKS wrote:
Hi list

I work for an small ISP, which does traditional xDSL service with PPPoE.
Currently we are in the process of migrating most of our customers to
DHCP (some customers are getting new CPEs and some will be sw upgraded
remotely ). It would be great if someone has the time to share their
experience (on- or offline) from such a migration. Common pitfals and
perhaps what whey would do differently "next time".
I know that every network is different but I believe that there are
some general concerns, specially around security of DHCP and security
features for vendors around DHCP and DHCP snooping etc.


We run PPPoE for the reasons that it's easier to manage and account for and does not rely on the middle layer for any security (implemented at the pppoe concentrator). There are also technical features we like, such as being able to route subnets easilly, and per-user filtering rules if necessary, as well as a high level of integration with radius that really makes things sing along.

A downside is rampant poor, non-compliant and downright buggy pppoe client implementations. It's gotten better over the years with more linux replacing other embedded development tool sets but still, it's downright criminal sometimes what that lower end consumer junk does in the field - and ALWAYS, being resolved by pulling the power and cycling it... <sigh>

I've recently implemented PPPoE Intermediate agent support as a patch against the opensource RP-PPPOE server software, along with documentation on integrating it with freeradius, and this enables you to ditch completely the username / password and just go with DSLAM port-id based authentication, reducing the strain on your support staff as end users forget or lose this otherwise most critical information. For anyone who cares, the code is on sourceforge -

http://ilc-ppp.sourceforge.net


Mike-



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