Restrict mtu

Signed-off-by: Alan Moore <alan.moore@canonical.com>

Author: alanmcanonical

tests/ssg_test_suite/test_env.py

@@ -533,6 +533,7 @@ def _new_container_from_image(self, image_name, container_name):
                       "--cap-add=cap_sys_admin",
                       "--cap-add=cap_sys_chroot",
                     #   "--privileged",
+                      "--network", "slirp4netns:mtu=1500",
                       "--publish", "{}".format(self.internal_ssh_port), "--detach", image_name,
                       "/usr/sbin/sshd", "-p", "{}".format(self.internal_ssh_port), "-D"]
         try: