Subject: [homenet] Multiple routers in the home

From: Jan Newmarch <[email-masked]>
Date: Sat, 11 May 2019 17:31:57 +1000

I'm new to this list so may cover old ground, be off topic, etc. Feel
free to shoot me down!

Barbara Stark writes [homenet rechartering, meetings, and code}

   Multiple routers just for the purpose of having multiple (general
   purpose) routers may not be a common use case?

I would suggest that's because the use cases discussed so far seem to
be almost limited to guest networks and work vlans. I know the IETF is
about technical issues, but that isn't selling the idea to the home
market. So how about talking about the way the home network might be
divided up:

Social: work networks for mum and dad; teenager network filled with RAP
music; young child network, very protected; family network with the TV,
web server with family photos, etc

Location: kitchen network with recipe server linked to cookers,
microwaves etc; family room with lots of PCs, tablets etc with lots of
games and shared resources

Function: lighting network(s) with 100 bulbs*; low-power garden
network; air con.

So these would suggest multiple purposes even in the home, and subnets
for each would be a good way of managing it. Yes, many nodes would be
on multiple subnets, but that isn't a problem.

When IPv6 talks about everything having an address, people jump up and
down about their microwave being on the internet. We know that isn't
true: addressability is not accessibility, and firewalls are in common
use block global accessibility. 

Homenet adds to addressability, with household-wide naming and service
discovery. I suggest Homenet needs to bring the discussion about
accessability inside the home to manage these different subnets, and
not just at the internet gateway. So the young child network should be
in a tightly controlled domain. Similarly, I would want my work servers
protected against viruses and ransomware brought into the network by
others. When the teenager has a party with 30 curious, technically
savvy and possibly socially immature friends, I want to be able to wall
them off from playing party games with the lights in my bedroom, say.

I'm on more shaky ground here, but I don't see much about L2 firewalls.
I see Eero has Family profiles for its mesh networks, but I guess this
is done in a non-standard way and is probably not as well-developed as
L3 firewalls. On the other hand, L3 firewalls are well understood and
supported by all routers (and OpenWRT, of course).

* looking at e.g. the LIFX forum ("Maximum/many bulbs on a single
network"), reports are that most home routers fail at handling more
than 30 nodes on a single SSID, and other reports are that 30 nodes per
home will the _average_ number within a year or two in Australia at
least. Multiple (or expensive) routers seem to  be the only solution
anyway.

Cheers

Jan
-- 
Dr Jan Newmarch,
Associate Professor, Box Hill Institute

Adjunct Professor, University of Canberra
Adjunct Lecturer, Charles Sturt University

P 03 9286 9971
M +61 4 0117 0509
W jan.newmarch.name
E [email-masked]

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From: "Walter H." <[email-masked]>
Date: Sat, 11 May 2019 10:13:18 +0200

>     purpose) routers may not be a common use case?
I'd say this is very common, that you have TWO routers cascaded ...

the outer one comes from your ISP, the inner one is your own ...

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From: joel jaeggli <[email-masked]>
Date: Sat, 11 May 2019 13:51:31 -0700

> the outer one comes from your ISP, the inner one is your own ...

Basically everyone who doesn't like their cable modem or at&t cpe that
much is in this category. in many cases some of these would benifit from
being bridged, but wether they would or not is orthagional to whether
not they are. when they subnet for the purposes of guest network or vlan
isolation they definitely cannot be bridged.

> 
> _______________________________________________
> homenet mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/homenet
>

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From: Mikael Abrahamsson <[email-masked]>
Date: Sun, 12 May 2019 08:03:24 +0200 (CEST)

On Sat, 11 May 2019, Jan Newmarch wrote:

> network"), reports are that most home routers fail at handling more than 
> 30 nodes on a single SSID, and other reports are that 30 nodes per home 
> will the _average_ number within a year or two in Australia at least. 
> Multiple (or expensive) routers seem to be the only solution anyway.

I've heard reports of HGWs that start to have problems when they're seeing 
more than ~30 simultaneous IPv4 devices connected to it, and it doesn't 
matter if they're wired or wifi. This is of course an implementation 
problem and not an architecture problem.

The home multiple router problem deployment cases I've seen so far (apart 
from the ones already mentioned) is to support IOT gateways. I've also 
personally deployed it to create separate L2 domains because I had 
unwanted STP interaction between some of my L2 switches and a 
virtualisation server running Linux bridging. The last one I guess isn't 
representative for most people, but I still see the need for intentional 
L2 separation (also to support completely different L1/L2 technologies) as 
a driver to have multiple routers within the home.

-- 
Mikael Abrahamsson    email: [email-masked]

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From: "Walter H." <[email-masked]>
Date: Sun, 12 May 2019 09:55:02 +0200

On 11.05.2019 22:51, joel jaeggli wrote:
> being bridged,
depends ...
not being bridged can mean a higher level of safety;
> when they subnet for the purposes of guest network or vlan
depends on how this is done ...
in case the own router does the subnetting, bridging is possible