Some devices randomly losing their IPv4 address

[Julien Pierre]

Kenneth,
Thanks for your quick reply. Response inline.

On Tue, Apr 5, 2022, 15:09 Kenneth Porter <shiva at sewingwitch.com> wrote:

> I feel your pain. That's why I run a router as an "Internet condom"
> between the Comcast modem and my LAN. I run ISC on an internal server.
> (I'm still having trouble getting the router to pass the IPv6 stuff
> through.) I also started using the Kea server at home, but still use ISC
> at the office. (Kea might be a better choice for a reservation-heavy
> system. I suggest setting it up alongside and temporarily disabling the
> ISC one to test. It should be easy to migrate just your config file,
> since with all systems handled by reservations, you don't need to
> migrate a lease file. Use the keama command to convert your config file.)
>

Thanks. I hadn't heard of the Kea DHCP server. I just checked the
description, and it looks like something I want to try.

Currently, I'm using ISC with Webmin as the GUI, but mostly doing edits
manually in the config file since it's so much faster.

As to "Internet condom", I do want to isolate some IoT devices from the
rest of the LAN in the future, and perhaps use VLANs, but those are
definitely things outside the scope of this post. One thing at a time.

>
> I'm only buying the 300 Mbps tier, which most current routers can
> handle. Why do you need 1.2 GBps? Is it something that fq_codel or cake
> can't handle? It's my understanding that the current Comcast modems
> enable good bufferbloat mitigation so the connection sharing should be
> pretty good with multiple bandwidth abusers running. So one should be
> able to have multiple gamers and meetings at the same time at the lower
> speed. Good way to save some money, too.
>

I don't really "need" 1.2 Gbps. 1.2 Gbps is what's guaranteed, but 1.4 Gbps
is what's actually delivered. My connection was upgraded from the 1 Gbps
tier at no cost, and the gateway upgraded from XB6 to XB7 also at no cost.
I was on the Gigabit tier not because I needed the highest download speed,
but because that's the only way to get their maximum upload speed, which is
a paltry 45 Mbps. I'm in a long term (2 year) contract as there are no
other ISPs available where I live. I have been waiting 12 years for AT&T to
lay it. I don't think it's ever happening on my side of the hill. Not sure
if I can save money by lowering the tier given the contract. It might be
possible, but my upload speed would go down if I did.
Technically, I could switch to 1 Gbps router and use the modem in bridge
mode. I would lose 400 Mbps of the download speed I'm paying for, though.
And the only wired router I own right now is a Ubiquiti USG, which is a
pretty terrible router, constantly getting broken by firmware regressions,
that I need to list on ebay.  Not sure if my Raspberry Pi 4B would be a
suitable Gigabit router. My Odroid XU4 might work better. It's much older,
but still faster than the Pi4GB -  but it's 32-bit only, and that is a
problem to run the Unifi controller for my wireless APs that requires
modern versions of MongoDB that dropped support for 32-bit CPUs.

On the DHCP client problem, have you seen anything interesting in the
> client logs when they should have renewed and gotten a new address?
> Recall that a client is supposed to renew its lease when 50% of the time
> has passed, so it should have attempted a few times before giving up.
>

Thanks, I hadn't thought of that. I don't have access to the logs for many
of the devices on which this happened, which are off-the-shelf Wifi
devices. For the single-board computers, I do have access, I'm going to
look into it. I didn't write down the time for previous events, though. For
the HAOS event this morning, Docker gets in the way of getting real system
logs, unfortunately. I believe I can recreate the problem if I lower DHCP
lease periods, though, and may be it a try, so I can look at the other
devices logs.

Thanks again,
Julien
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