Post by @rqm

I found 2 things:

https://gist.github.com/baryluk/e9ba5af68d67e14b8a5716a70656d550

# To configure loopback / localhost:
# ip/ipconfig -P loopback /dev/null 127.1
# ip/ipconfig -P loopback /dev/null ::1

https://man.cat-v.org/plan_9/3/loopback
Manpage states "#X", not "#λ", not sure if this changes anything, I do not even run The 9.