Имеем контейнер в котором нужно организовать роутер. Вот конфиг:
root@bras:~# cat /etc/systemd/system/ppp.service
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
[Unit]
Description=Container %i
Documentation=man:systemd-nspawn(1)
PartOf=machines.target
Before=machines.target
After=network.target systemd-resolved.service
ConditionPathIsReadWrite=/proc
[Service]
ExecStart=/usr/bin/systemd-nspawn -D /vm/ppp --quiet --keep-unit --boot --link-journal=try-guest --network-bridge=beth0 --machine=%i
KillMode=mixed
Type=notify
RestartForceExitStatus=133
SuccessExitStatus=133
Slice=machine.slice
#Delegate=yes
## Enforce a strict device policy, similar to the one nspawn configures
## when it allocates its own scope unit. Make sure to keep these
## policies in sync if you change them!
DevicePolicy=closed
DeviceAllow=/dev/ppp rwm
DeviceAllow=char-pts rw
# nspawn itself needs access to /dev/loop-control and /dev/loop, to
# implement the --image= option. Add these here, too.
DeviceAllow=/dev/loop-control rw
DeviceAllow=block-loop rw
DeviceAllow=block-blkext rw
[Install]
WantedBy=machines.target
root@ppp:~# echo 1 > /proc/sys/net/ipv6/conf/all/forwarding
-bash: /proc/sys/net/ipv6/conf/all/forwarding: Read-only file system
