Automatically switch default route to secondary uplink when primary uplink is unavailable

[Thomas Glanzmann]

Hello,
I have dark fibre with a static ip and a DSL line behind a NAT box. I
would like to have the default route on the dark fibre and switch to the
DSL line when the dark fibre is unavailable. I determine if the line is
available by ping 1.1.1.1 and 8.8.8.8. I implemented the above in perl,
but wonder if I reimplemented the wheel and this is already possible
with frr, bird or another piece of software on Linux? Here I don't have
BGP available.

Find my perl Daemon here (public IPs changed), it runs every minute by
cron.

https://tg.st/u/genericrouteswitcher.pl

Cheers,
        Thomas