SLIP interface inside container

Greetings.

System: Debian-8.10 updated to date.
Installed: lxc_1%3a1.0.6-6+deb8u6_i386.deb

Trying to launch slip interface inside container
between application and linux.

Successfully created belows:
socat PIPE:/dev/ttyq0 PIPE:/dev/ptyq0 &
socat -d -d -ly PTY,link=/dev/ttyq0 PTY,link=/dev/ptyq0 &

As a result inside container I see two devices @ptyq0 and @ttyq0

eth0 is 192.168.122.203

Attempt to create slip fails…
/sbin/slattach -s 115200 -p slip /dev/ptyq0 &

with message
root@cont:/# ifconfig sl0 192.168.122.203 netmask 255.255.255.255 pointopoint 192.168.122.204 mtu 576 up
SIOCSIFADDR: No such device
sl0: ERROR while getting interface flags: No such device
SIOCSIFNETMASK: No such device
SIOCSIFDSTADDR: No such device
sl0: ERROR while getting interface flags: No such device
SIOCSIFMTU: No such device
sl0: ERROR while getting interface flags: No such device
root@cont:/#

I wonder whether it is possible at all.

All suggestions will be much appreciated.