Sat Dec 14 08:19:19 CET 2024

I recently switched my mode of Internet to be LTE Phone based only.  Gone forever are the days of DSL, 25 years
in the making.  If I ever get a landline Internet connection again, it'll be fibre-optics only not copper.

I had some problems with the Wifi tethering, as there is, what I suspect is a Wifi-deauther/jammer in the
vicinity (which by the way is illegal!).  Mobian had a USB cable tether set up working out of the box, but it
took me several days to find how I could do it with Manjaro.  The reason why I went to Manjaro escapes me right
now but there was one, making me prefer it over Mobian and Ubuntu Mobile (both I tried).

So here is what you have to set up on Manjaro to get the usb0 tether working.  These are the files I changed
listed with find in /etc with line numbers (on the pinephone pro running Manjaro Linux).

./systemd/network/50-static.network
     1	[Match]
     2	Name=usb0
     3	[Network]
     4	Address=172.16.253.2/24
     5	Gateway=173.16.253.1
     6	IPForward=yes
     7	Address=fcfc:ffff::1/64
     8	IPv6SendRA=yes
./iptables/iptables.rules
     1	# Generated by iptables-save v1.8.10 on Sat Dec 14 05:51:11 2024
     2	*nat
     3	:PREROUTING ACCEPT [0:0]
     4	:INPUT ACCEPT [0:0]
     5	:OUTPUT ACCEPT [1:128]
     6	:POSTROUTING ACCEPT [1:128]
     7	-A POSTROUTING -o ppp0 -j MASQUERADE
     8	COMMIT
     9	# Completed on Sat Dec 14 05:51:11 2024
    10	# Generated by iptables-save v1.8.10 on Sat Dec 14 05:51:11 2024
    11	*filter
    12	:INPUT ACCEPT [10345:810671]
    13	:FORWARD ACCEPT [0:0]
    14	:OUTPUT ACCEPT [9787:1608151]
    15	COMMIT
    16	# Completed on Sat Dec 14 05:51:11 2024
./iptables/ip6tables.rules
     1	# Generated by ip6tables-save v1.8.10 on Sat Dec 14 06:11:20 2024
     2	*nat
     3	:PREROUTING ACCEPT [0:0]
     4	:INPUT ACCEPT [0:0]
     5	:OUTPUT ACCEPT [3:319]
     6	:POSTROUTING ACCEPT [0:0]
     7	-A POSTROUTING -o ppp0 -j MASQUERADE
     8	COMMIT
     9	# Completed on Sat Dec 14 06:11:20 2024
./modules-load.d/peter.conf
     1	phy-generic
     2	g_cdc

Here is the config changes I made on my OpenBSD laptop:


/etc/hostname.cdce0
inet6 fcfc:ffff::2 64
inet 172.16.253.1/24
up
!/sbin/route add 10.74.210.211 172.16.253.2
!/sbin/route add 49.12.42.182 172.16.253.2
!/sbin/route change default 172.16.253.2
!/sbin/route add -inet6 default fcfc:ffff::1

And finally a crontab to scan ifconfig cdce0 and if it exists to sh /etc/netstart cdce0, that's it!

CAVEATS and WISHLIST:

It would be nice if the cdce0 interface wouldn't disappear every time the link goes down.  Either way, the
crontab worked.  I also need to add a forwarding for IPv6 in the systemd setup.