Нет, проблема не в ключах pppd. Проблема в том, что клиент xl2tp не может с openl2tp договориться на длину для управляющих сообщений.10.255.101.71 - клиент xl2tpd
10.255.101.70 - виндовый клиент
10.255.150.4 - сервер openl2tpd
Машина с xlt2pd с коннектом к openl2tpd
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
16:40:31.042022 IP 10.255.101.71.l2f > 10.255.150.4.l2f: l2tp:[TLS](0/0)Ns=0,Nr=0 *MSGTYPE(SCCRQ) *PROTO_VER(1.0) *FRAMING_CAP(AS) *BEARER_CAP() *FIRM_VER(1680) *HOST_NAME(debian) *VENDOR_NAME(xelerance.com) *ASSND_TUN_ID(46420) *RECV_WIN_SIZE(4)
16:40:31.042381 IP 10.255.150.4.46339 > 10.255.101.71.l2f: l2tp:[TLS](46420/0)Ns=0,Nr=1 *MSGTYPE(SCCRP) *PROTO_VER(1.0) *FRAMING_CAP(AS) *BEARER_CAP(AD) FIRM_VER(264) *HOST_NAME(debian) VENDOR_NAME(Katalix Systems Ltd. Linux-3.2.34 (x86_64)) *ASSND_TUN_ID(50850) *RECV_WIN_SIZE(10)
16:40:31.047114 IP 10.255.101.71.l2f > 10.255.150.4.l2f: l2tp:[TLS](50850/0)Ns=1,Nr=1 *MSGTYPE(SCCCN)
16:40:31.047759 IP 10.255.101.71.l2f > 10.255.150.4.l2f: l2tp:[TLS](50850/0)Ns=2,Nr=1 *MSGTYPE(ICRQ) *ASSND_SESS_ID(49539) *CALL_SER_NUM(1) *BEARER_TYPE()
16:40:31.047911 IP 10.255.150.4.46339 > 10.255.101.71.l2f: l2tp:[TLS](46420/49539)Ns=1,Nr=3 *MSGTYPE(ICRP) *ASSND_SESS_ID(37081)
16:40:31.054758 IP 10.255.101.71.l2f > 10.255.150.4.l2f: l2tp:[TLS](50850/37081)Ns=3,Nr=2 *MSGTYPE(ICCN) *TX_CONN_SPEED(100000000) *FRAMING_TYPE(S) *RX_CONN_SPEED(0)
16:40:31.059051 IP 10.255.150.4.46339 > 10.255.101.71.l2f: l2tp:[](46420/49539) {LCP, Conf-Request (0x01), id 1, length 15}
16:40:31.763007 IP 10.255.150.4.46339 > 10.255.101.71.l2f: l2tp:[TLS](46420/0)Ns=2,Nr=4 ZLB
16:40:32.066959 IP 10.255.101.71.l2f > 10.255.150.4.l2f: l2tp:[](50850/37081) {LCP, Conf-Request (0x01), id 1, length 31}
16:40:34.062327 IP 10.255.150.4.46339 > 10.255.101.71.l2f: l2tp:[](46420/49539) {LCP, Conf-Request (0x01), id 1, length 15}
16:40:34.065772 IP 10.255.101.71.l2f > 10.255.150.4.l2f: l2tp:[](50850/37081) {LCP, Conf-Ack (0x02), id 1, length 15}
16:40:35.071690 IP 10.255.101.71.l2f > 10.255.150.4.l2f: l2tp:[](50850/37081) {LCP, Conf-Request (0x01), id 1, length 31}
16:40:37.065582 IP 10.255.150.4.46339 > 10.255.101.71.l2f: l2tp:[](46420/49539) {LCP, Conf-Request (0x01), id 1, length 15}
16:40:37.069800 IP 10.255.101.71.l2f > 10.255.150.4.l2f: l2tp:[](50850/37081) {LCP, Conf-Ack (0x02), id 1, length 15}
16:40:38.071173 IP 10.255.101.71.l2f > 10.255.150.4.l2f: l2tp:[](50850/37081) {LCP, Conf-Request (0x01), id 1, length 31}
16:40:40.068864 IP 10.255.150.4.46339 > 10.255.101.71.l2f: l2tp:[](46420/49539) {LCP, Conf-Request (0x01), id 1, length 15}
16:40:40.075949 IP 10.255.101.71.l2f > 10.255.150.4.l2f: l2tp:[](50850/37081) {LCP, Conf-Ack (0x02), id 1, length 15}
И идут запросы пока lcp ограничитель на сервере не сработает ...
Виндовая машина с коннектом к openl2tpd
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
16:51:33.928495 IP 10.255.101.70.l2f > 10.255.150.4.l2f: l2tp:[TLS](0/0)Ns=0,Nr=0 *MSGTYPE(SCCRQ) *PROTO_VER(1.0) *FRAMING_CAP(S) *BEARER_CAP() FIRM_VER(1537) *HOST_NAME(KUL-PC) VENDOR_NAME(Microsoft) *ASSND_TUN_ID(12) *RECV_WIN_SIZE(8)
16:51:33.928821 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[TLS](12/0)Ns=0,Nr=1 *MSGTYPE(SCCRP) *PROTO_VER(1.0) *FRAMING_CAP(AS) *BEARER_CAP(AD) FIRM_VER(264) *HOST_NAME(debian) VENDOR_NAME(Katalix Systems Ltd. Linux-3.2.34 (x86_64)) *ASSND_TUN_ID(1878) *RECV_WIN_SIZE(10)
16:51:33.932703 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[TLS](1878/0)Ns=1,Nr=1 *MSGTYPE(SCCCN)
16:51:33.932719 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[TLS](1878/0)Ns=3,Nr=1 ZLB
16:51:33.932961 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[TLS](1878/0)Ns=2,Nr=1 *MSGTYPE(ICRQ) *ASSND_SESS_ID(1) *CALL_SER_NUM(0) *BEARER_TYPE(A) VENDOR0137:ATTR0001(8f5cac3a5ffabf499d18fe9701a84188)
16:51:33.933123 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[TLS](12/1)Ns=1,Nr=3 *MSGTYPE(ICRP) *ASSND_SESS_ID(23271)
16:51:33.935520 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[TLS](1878/23271)Ns=3,Nr=2 *MSGTYPE(ICCN) *TX_CONN_SPEED(100000000) *FRAMING_TYPE(S) PROXY_AUTH_TYPE(No Auth)
16:51:33.935533 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[TLS](1878/0)Ns=4,Nr=2 ZLB
16:51:33.939807 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[](12/1) {LCP, Conf-Request (0x01), id 1, length 15}
16:51:33.941860 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {LCP, Conf-Request (0x01), id 0, length 23}
16:51:33.941977 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[](12/1) {LCP, Conf-Reject (0x04), id 0, length 15}
16:51:33.947024 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {LCP, Conf-Ack (0x02), id 1, length 15}
16:51:33.948150 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {LCP, Conf-Request (0x01), id 1, length 14}
16:51:33.948233 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[](12/1) {LCP, Conf-Ack (0x02), id 1, length 14}
16:51:33.948356 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[](12/1) {CHAP, Challenge (0x01), id 140, Value f446372201826ddb81c918e385532be08bd2481ec68cb6, Name debian}
16:51:33.950899 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {LCP, Ident (0x0c), id 2, length 20}
16:51:33.950923 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {LCP, Ident (0x0c), id 3, length 24}
16:51:33.950930 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {LCP, Ident (0x0c), id 4, length 26}
16:51:33.950992 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {CHAP, Response (0x02), id 140, Value c94bfa8e29174bfb1c43a33c3a31bc72, Name ppphds50_13}
16:51:34.448341 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[](12/1) {CHAP, Success (0x03), id 140, Msg }
16:51:34.448562 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[](12/1) {IPCP, Conf-Request (0x01), id 1, length 12}
16:51:34.454009 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {IPCP, Conf-Request (0x01), id 5, length 36}
16:51:34.454026 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {IPCP, Conf-Ack (0x02), id 1, length 12}
16:51:34.454179 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[](12/1) {IPCP, Conf-Nack (0x03), id 5, length 36}
16:51:34.463424 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {IPCP, Conf-Request (0x01), id 6, length 36}
16:51:34.463593 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[](12/1) {IPCP, Conf-Ack (0x02), id 6, length 36}
16:51:34.497211 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {IP 46.8.xxx.170 > igmp.mcast.net: igmp v3 report, 1 group record(s)}
16:51:34.497450 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {IP 46.8.xxx.170.53875 > 224.0.0.252.hostmon: UDP, length 24}
16:51:34.513037 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[TLS](12/0)Ns=2,Nr=4 ZLB
16:51:34.518969 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {IP 46.8.xxx.170.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request, length 300}
16:51:34.555636 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {IP 46.8.xxx.170.netbios-ns > 11.0.0.1.netbios-ns: NBT UDP PACKET(137): MULTIHOMED REGISTRATION; REQUEST; UNICAST}
16:51:34.555644 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {IP 46.8.xxx.170.netbios-ns > 11.0.0.1.netbios-ns: NBT UDP PACKET(137): REGISTRATION; REQUEST; UNICAST}
16:51:34.555651 IP 10.255.101.70.l2f > 10.255.150.4.51874: l2tp:[L](1878/23271) {IP 46.8.xxx.170.netbios-ns > 11.0.0.1.netbios-ns: NBT UDP PACKET(137): MULTIHOMED REGISTRATION; REQUEST; UNICAST}
16:51:34.555761 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[](12/1) {IP 11.0.0.1 > 46.8.xxx.170: ICMP 11.0.0.1 udp port netbios-ns unreachable, length 104}
16:51:34.555879 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[](12/1) {IP 11.0.0.1 > 46.8.xxx.170: ICMP 11.0.0.1 udp port netbios-ns unreachable, length 104}
16:51:34.555990 IP 10.255.150.4.51874 > 10.255.101.70.l2f: l2tp:[](12/1) {IP 11.0.0.1 > 46.8.xxx.170: ICMP 11.0.0.1 udp port netbios-ns unreachable, length 104}
Всё, трафик побежал ...