Domain name based multihome routing?

Darcy Kevin (FCA) kevin.darcy at
Wed Jun 27 17:27:52 UTC 2018

I’m not convinced DNS has any valuable role to play here. Seems like this is a traffic-shaping challenge; maybe one of the open source traffic shaping tools would fit the bill.

                                                                                                                                                                                                                - Kevin

From: bind-users <bind-users-bounces at> On Behalf Of Dale Mahalko
Sent: Wednesday, June 27, 2018 1:00 PM
To: bind-users at
Subject: Re: Domain name based multihome routing?

There is no way to know if this is the "right" or "wrong" approach without actually trying it and see what happens.

Guessing the potential background domains used by Microsoft / Steam, etc and monitoring bandwidth used by those domains is unfortunately the only option available. It's not like any of these companies are willing to outright divulge anything about these background details to anyone outside their business.

As far as load on the router goes for keeping track of possibly tens of thousands of custom routes, I am fine with dedicating a fast Intel i5 or i7 and a couple gigabytes of memory to the job. Most routers are tiny little things with very little CPU needed for normal routing, with the heavy lifting only happening if encryption is needed for a bunch of VPN connections.

On Wed, Jun 27, 2018 at 9:16 AM, Matus UHLAR - fantomas <uhlar at<mailto:uhlar at>> wrote:
On Tue, Jun 26, 2018 at 12:45 PM, Grant Taylor via bind-users <
bind-users at<mailto:bind-users at>> wrote:
Are you saying that you want to dynamically update routes to IPs resolved
in real time to specific host / domain names?  Such that traffic to
specific hosts / domain names is routed over DSL?  With things that don't
match conditions routed over cell?

I think I understand what you want to do and why you want to do it.

It seems like you're using named as the source of information to feed into
the process that dynamically updates routing.

I find the pausing of named to be questionable.  But I understand that you
want to make sure that no connections are started until after the
(re)routing has been done.

On 26.06.18 14:07, Dale Mahalko wrote:
(I am no programming expert as mentioned, but I do IT stuff for a living,

The pause would only be long enough to look for a regex domain pattern to
be routed to the DSL, and then creating the route. This pause can likely be
measured in nanoseconds.

I don't think this could be done in nanoseconds. Maybe microseconds, but
more probably miliseconds.

Another question would be, how fast your router can be with potentially
thousands of routes (I know, many OSes have routing optimised very hardly).
This would likely be a multithreaded asynchronous mechanism so that BIND
does each of its lookups as usual, and then forks a followup thread after
it completes its normal lookup process, to do the pattern match and route
creation, followed by the delayed response released when the
pattern-match/route-creation thread terminates.

So in general using multithreading, there would be no real impact to
programs requesting the lookups, other than a delay per lookup that is so
small it would not be noticeable to an end-user human.

I think that you are trying wrong approach, using wrong tools.
Guessing the potential usage from DNS is not a goog idea.

On your router, configure firewall to route selected protocols (gaming, ssh,
RDP, dns) and maybe later some sites to paid cellular and router everything
other to DSL.

Note that at my home, most of data is spend by my children watching youtube
videos - I don't think that routing general web and streaming services to
cell connection would help you with anything.

Matus UHLAR - fantomas, uhlar at<mailto:uhlar at> ;
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
M$ Win's are shit, do not use it !

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