У меня похожая ситуация. Пытаюсь настроить билайновское l2tp. По dhcp получаю ip, tp.internet.beeline.ru пингуется. Потом запускаю xl2tpd -D, и через некоторое время комп виснет. Как делаю:
[[email protected] ~]# dhcpcd
dhcpcd[879]: version 6.6.4 starting
dhcpcd[879]: DUID 00:01:00:01:1b:fa:83:17:44:8a:5b:5c:6b:2f
dhcpcd[879]: enp2s0: IAID 5b:5c:6b:2f
dhcpcd[879]: enp2s0: soliciting an IPv6 router
dhcpcd[879]: enp2s0: rebinding lease of 10.174.152.228
dhcpcd[879]: enp2s0: changing route to 10.174.152.0/21
dhcpcd[879]: enp2s0: changing route to 10.0.0.0/8 via 10.174.152.1
dhcpcd[879]: enp2s0: changing route to 78.107.196.0/22 via 10.174.152.1
dhcpcd[879]: enp2s0: changing route to 233.32.240.0/24 via 10.174.152.228
RTNETLINK answers: File exists
dhcpcd[879]: forked to background, child pid 892
[[email protected] ~]# ping tp.internet.beeline.ru
PING tp.internet.beeline.ru (85.21.59.41) 56(84) bytes of data.
64 bytes from bras-lo0.omsk.corbina.net (85.21.59.41): icmp_seq=1 ttl=247 time=2.68 ms
64 bytes from bras-lo0.omsk.corbina.net (85.21.59.41): icmp_seq=2 ttl=247 time=1.76 ms
64 bytes from bras-lo0.omsk.corbina.net (85.21.59.41): icmp_seq=3 ttl=247 time=1.66 ms
64 bytes from bras-lo0.omsk.corbina.net (85.21.59.41): icmp_seq=4 ttl=247 time=1.30 ms
[[email protected] ~]# ip route
default via 10.174.152.1 dev enp2s0  metric 202
10.0.0.0/8 via 10.174.152.1 dev enp2s0  metric 202
10.174.152.0/21 dev enp2s0  proto kernel  scope link  src 10.174.152.228  metric 202
78.107.196.0/22 via 10.174.152.1 dev enp2s0  metric 202
233.32.240.0/24 via 10.174.152.228 dev enp2s0  metric 202
Затем
[[email protected] ~]# xl2tpd -D
xl2tpd[919]: setsockopt recvref[30]: Protocol not available
xl2tpd[919]: Using l2tp kernel support.
xl2tpd[919]: xl2tpd version xl2tpd-1.3.6 started on localhost PID:919
xl2tpd[919]: Written by Mark Spencer, Copyright (C) 1998, Adtran, Inc.
xl2tpd[919]: Forked by Scott Balmos and David Stipp, (C) 2001
xl2tpd[919]: Inherited by Jeff McAdams, (C) 2002
xl2tpd[919]: Forked again by Xelerance (www.xelerance.com) (C) 2006
xl2tpd[919]: Listening on IP address 0.0.0.0, port 1701
xl2tpd[919]: Connecting to host tp.internet.beeline.ru, port 1701
xl2tpd[919]: Connection established to 85.21.59.57, 1701.  Local: 12167, Remote: 59438 (ref=0/0).
xl2tpd[919]: Calling on tunnel 12167
xl2tpd[919]: Call established with 85.21.59.57, Local: 60679, Remote: 44232, Serial: 1 (ref=0/0)
xl2tpd[919]: start_pppd: I'm running:
xl2tpd[919]: "/usr/sbin/pppd"
xl2tpd[919]: "passive"
xl2tpd[919]: "nodetach"
xl2tpd[919]: ":"
xl2tpd[919]: "name"
xl2tpd[919]: "0895690796"
xl2tpd[919]: "debug"
xl2tpd[919]: "file"
xl2tpd[919]: "/etc/ppp/options.xl2tpd"
xl2tpd[919]: "plugin"
xl2tpd[919]: "pppol2tp.so"
xl2tpd[919]: "pppol2tp"
xl2tpd[919]: "7"
Дальше этого не идёт. Потом в журнале появляются сообщения, что первое ядро занято одним процессом уже 23 секунды. Потом второе ядро, третье и всё намертво виснет. Если успеть остановить, то нормально:
^C
xl2tpd[919]: death_handler: Fatal signal 2 received
xl2tpd[919]: Terminating pppd: sending TERM signal to pid 926
xl2tpd[919]: Connection 59438 closed to 85.21.59.57, port 1701 (Server closing)
Вывод журнала, когда успеваю остановить:
дек 12 22:04:21 localhost kernel: PPP generic driver version 2.4.2
дек 12 22:04:21 localhost kernel: NET: Registered protocol family 24
дек 12 22:04:21 localhost kernel: l2tp_core: L2TP core driver, V2.0
дек 12 22:04:21 localhost kernel: l2tp_netlink: L2TP netlink interface
дек 12 22:04:21 localhost kernel: l2tp_ppp: PPPoL2TP kernel driver, V2.0
дек 12 22:04:21 localhost pppd[926]: Plugin pppol2tp.so loaded.
дек 12 22:04:21 localhost pppd[926]: pppd 2.4.7 started by root, uid 0
дек 12 22:04:21 localhost pppd[926]: using channel 1
дек 12 22:04:21 localhost pppd[926]: Using interface ppp0
дек 12 22:04:21 localhost pppd[926]: Connect: ppp0 <-->
дек 12 22:04:21 localhost pppd[926]: Overriding mtu 1500 to 1460
дек 12 22:04:21 localhost pppd[926]: PPPoL2TP options: debugmask 0
дек 12 22:04:21 localhost pppd[926]: Overriding mru 1500 to mtu value 1460
дек 12 22:04:21 localhost pppd[926]: sent [LCP ConfReq id=0x1 <mru 1460> <asyncmap 0x0> <magic 0x4c717b98>]
дек 12 22:04:21 localhost pppd[926]: rcvd [LCP ConfReq id=0x1 <mru 1460> <asyncmap 0xa0000> <auth pap> <magic 0x59ced27b> <pcomp> <accomp>]
дек 12 22:04:21 localhost pppd[926]: sent [LCP ConfNak id=0x1 <auth eap>]
дек 12 22:04:21 localhost pppd[926]: rcvd [LCP ConfAck id=0x1 <mru 1460> <asyncmap 0x0> <magic 0x4c717b98>]
дек 12 22:04:21 localhost pppd[926]: rcvd [LCP ConfReq id=0x2 <mru 1460> <asyncmap 0xa0000> <auth chap MD5> <magic 0x59ced27b> <pcomp> <accomp>]
дек 12 22:04:21 localhost pppd[926]: sent [LCP ConfAck id=0x2 <mru 1460> <asyncmap 0xa0000> <auth chap MD5> <magic 0x59ced27b> <pcomp> <accomp>]
дек 12 22:04:21 localhost pppd[926]: PPPoL2TP options: debugmask 0
дек 12 22:04:21 localhost pppd[926]: sent [LCP EchoReq id=0x0 magic=0x4c717b98]
дек 12 22:04:21 localhost pppd[926]: rcvd [LCP EchoRep id=0x0 magic=0x59ced27b]
дек 12 22:04:21 localhost pppd[926]: rcvd [CHAP Challenge id=0x1 <e575b08ebff7806728fd7e51103a0dee>, name = "bras15.omsk"]
дек 12 22:04:21 localhost pppd[926]: sent [CHAP Response id=0x1 <454cf48f2a059fc80ac938832695db68>, name = "0895690796"]
дек 12 22:04:21 localhost pppd[926]: rcvd [CHAP Success id=0x1 ""]
дек 12 22:04:21 localhost pppd[926]: CHAP authentication succeeded
дек 12 22:04:21 localhost pppd[926]: CHAP authentication succeeded
дек 12 22:04:21 localhost pppd[926]: sent [IPCP ConfReq id=0x1 <addr 0.0.0.0>]
дек 12 22:04:21 localhost pppd[926]: rcvd [IPCP ConfReq id=0x1 <addr 85.21.59.57>]
дек 12 22:04:21 localhost pppd[926]: sent [IPCP ConfAck id=0x1 <addr 85.21.59.57>]
дек 12 22:04:21 localhost pppd[926]: rcvd [IPCP ConfNak id=0x1 <addr 176.15.125.93>]
дек 12 22:04:21 localhost pppd[926]: sent [IPCP ConfReq id=0x2 <addr 176.15.125.93>]
дек 12 22:04:21 localhost pppd[926]: rcvd [IPCP ConfAck id=0x2 <addr 176.15.125.93>]
дек 12 22:04:21 localhost pppd[926]: Script /etc/ppp/ip-pre-up started (pid 928)
дек 12 22:04:21 localhost pppd[926]: Script /etc/ppp/ip-pre-up finished (pid 928), status = 0x0
дек 12 22:04:21 localhost pppd[926]: Cannot determine ethernet address for proxy ARP
дек 12 22:04:21 localhost pppd[926]: local  IP address 176.15.125.93
дек 12 22:04:21 localhost pppd[926]: remote IP address 85.21.59.57
дек 12 22:04:21 localhost pppd[926]: Script /etc/ppp/ip-up started (pid 931)
дек 12 22:04:21 localhost pppd[926]: Script /etc/ppp/ip-up finished (pid 931), status = 0x0
дек 12 22:04:26 localhost pppd[926]: Terminating on signal 2
дек 12 22:04:26 localhost pppd[926]: Connect time 0.1 minutes.
дек 12 22:04:26 localhost pppd[926]: Sent 0 bytes, received 0 bytes.
дек 12 22:04:26 localhost pppd[926]: Script /etc/ppp/ip-down started (pid 936)
дек 12 22:04:26 localhost pppd[926]: Overriding mtu 1500 to 1460
дек 12 22:04:26 localhost pppd[926]: PPPoL2TP options: debugmask 0
дек 12 22:04:26 localhost pppd[926]: Overriding mru 1500 to mtu value 1460
дек 12 22:04:26 localhost pppd[926]: sent [LCP TermReq id=0x2 "User request"]
дек 12 22:04:26 localhost pppd[926]: Terminating on signal 15
дек 12 22:04:26 localhost pppd[926]: Script /etc/ppp/ip-down finished (pid 936), status = 0x0
дек 12 22:04:29 localhost pppd[926]: sent [LCP TermReq id=0x3 "User request"]
дек 12 22:04:32 localhost pppd[926]: Connection terminated.
дек 12 22:04:32 localhost pppd[926]: Modem hangup
дек 12 22:04:32 localhost pppd[926]: Exit.

Вот мои конфиги:
[[email protected] ~]# cat '/etc/xl2tpd/xl2tpd.conf'
[global]
access control = yes
auth file = /etc/ppp/chap-secrets
[lac beeline]
lns = tp.internet.beeline.ru
redial = yes
redial timeout = 1
require pap = no
require chap = yes
require authentication = no
name = ***
ppp debug = yes
pppoptfile = /etc/ppp/options.xl2tpd
autodial = yes
tx bps = 100000000
[[email protected] ~]# cat '/etc/ppp/options.xl2tpd'
name ***
remotename l2tp
ipparam beeline
connect /bin/true
mru 1460
mtu 1460
nodeflate
nobsdcomp
persist
maxfail 0
nopcomp
noaccomp
defaultroute
noauth
[[email protected] ~]# cat '/etc/ppp/ip-up.d/10-routing-up.sh'
#!/bin/sh
/bin/ip route del default
#/bin/ip route add default dev ppp0
/bin/ip route add default dev $1
[[email protected] ~]# cat '/etc/ppp/ip-down.d/10-routing-down.sh'
#!/bin/sh
/bin/ip route del default
/bin/ip route add default dev enp2s0
[[email protected] ~]# cat '/etc/dhcpcd.enter-hook'
[ "$if_up" = 'true' -a -n "$new_routers"  ] && ip route add default via "$new_routers" metric "$ifmetric"
В /etc/dhcpcd.conf есть
option classless_static_routes, static_routes, ms_classless_static_routes
Смущает то, что в /etc/ppp/ip-up.d/00-dns.sh я mv заменил на cp для проверки
cp /etc/ppp/resolv.conf /etc/resolv.conf
но после попытки подключения файла /etc/ppp/resolv.conf нет.