[Babel-users] resuming 1.8.3 deployment

[Dave Taht]

While I'm at it. A big lesson learned on this network (and from
looking over wlan-slovenia years ago)
was *export covering routes* and don't let all the local churn escape.
On leafy nodes, especially.

Try to keep things well below 1000 routes on every segment of the network.

be *good* and profligate about network numbering. If you need a /22
today, use a /20 for future proofing.
I was utterly profligate about giving myself a ipv4/14 to use
numbering the thing and still need to renumber bits of it
periodically. Tying
any of this to dns is a real pain, made worse by odhcpd not having a
good hook for it in the past.

Being a meshy protocol, though, if something escapes, usually over a
"backup" link, suddenly a whole bunch
more specific routes end up going through that backup link and life
goes to hell quickly. I ended up using
specific bssids when I had to share wifi channels to make sure that
didn't happen rather than filter it out in
babel.

openwrt has proto support which I used to automate injecting things
into babel from hacked up odhcpd
and other scripts as well as export those covering routes. I still
don't always get the filtering language in
babel right (or there's a bug), and still have deployed a mix of
babeld.conf /etc/config/babeld and so on.

I still find the whole babel src_ip and source specific stuff
confusing for ipv6.

It's not perfect (because openwrt makes certain things static that
should be another proto)

remember to disable dhcp's fetch of a default route (defaultroute 0)
if you use dhcp. static ips are
a pain unless you document the heck out of them

comcast only giving me ipv6/60s caused me fits. All I needed to do was
drag ipv6 out to the furthest reaches
of the network (on the aps), and for that I don't need to number any
of the intervening routers at all,
so something that could get ipv6 allocations over ipv4 would be just
fine. And when they go away,
deprecate them. address retractions work badly in just about
everything still... and boxes get dozens
of dying ipv6 addresses nowadays... tmp, static, dhcpv6, slaac,
privacy - and babeld wants to export all
these by default.... so at some point I'd tried to write a best
practice document for having these get
reduced to sanity.....


ok, back to flashing a few more routers on trees...