4.10-STABLE FreeBSD
Связку mgetty + pppd я вроде бы настроил нормально. Единственное, в драйвере не было строки 4.10-STABLE (но я просто сделал ссылку на 4.8, так как там всё одинаково).
И вот почему-то сыпятся ошибки.

Jun 17 16:02:04 ne login: 2 LOGIN FAILURES ON cuaa8
Jun 17 16:02:46 ne pppd[5899]: Modem hangup, connected for 1 minutes
Jun 17 16:02:46 ne pppd[5899]: Connection terminated, connected for 1 minutes
Jun 17 16:03:16 ne login: 2 LOGIN FAILURES ON cuaa8
Jun 17 16:03:21 ne login: 2 LOGIN FAILURES ON cuaa8
Jun 17 16:04:14 ne login: 1 LOGIN FAILURE ON cuaa8
Jun 17 16:04:28 ne pppd[5902]: pppd 2.3.5 started by root, uid 0
Jun 17 16:04:28 ne pppd[5902]: Connect: ppp0 <--> /dev/cuaa2
Jun 17 16:05:15 ne pppd[5902]: Connection terminated, connected for 1 minutes
Jun 17 16:06:08 ne pppd[5911]: pppd 2.3.5 started by root, uid 0
Jun 17 16:06:08 ne pppd[5911]: Connect: ppp0 <--> /dev/cuaa8
Jun 17 16:08:05 ne pppd[5919]: pppd 2.3.5 started by root, uid 0
Jun 17 16:08:05 ne pppd[5919]: Connect: ppp1 <--> /dev/cuaa2
Jun 17 16:08:07 ne pppd[5911]: Modem hangup, connected for 1 minutes
Jun 17 16:08:07 ne pppd[5911]: Connection terminated, connected for 1 minutes
Jun 17 16:08:49 ne pppd[5919]: Modem hangup, connected for 1 minutes
Jun 17 16:08:49 ne pppd[5919]: Connection terminated, connected for 1 minutes