我已经检查了很多其他的L2TP / IPsec VPN后，他们似乎没有完全匹配我遇到的问题，所以这里是怎么回事。
我试图在我的Arch Linux服务器上build立一个VPN，我可以从我的本地设备（其中大部分都运行Windows 8.1）连接到这个服务器。 对于整篇文章，我将使用123.1.1.1的假外部IP和Arch serverand 123.2.2.2的ff：ff：ff：ff作为我尝试连接的Windows 8.1桌面的IP。
我已经设置和运行下面的这个configuration设置的一切。 端口1701 TCP，4500 UDP和500 UDP在Arch服务器上正常打开，它不是ARM服务器，而是64位服务器。 当我尝试从Windows 8设备连接时，出现以下错误：
Error 789: The L2TP connection attempt failed because the security error encountered a processing error during the initial negotions with the remote computer. ipsec自动 – 状态 （我尝试连接后）
000 using kernel interface: netkey 000 interface lo/lo ::1 000 interface eth0/eth0 ff:ff:ff:ff::1 000 interface eth0/eth0 123.1.1.1 000 interface eth0/eth0 123.1.1.1 000 %myid = (none) 000 debug none 000 000 virtual_private (%priv): 000 - allowed 5 subnets: 10.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12, fd00::/8, fe80::/10 000 - disallowed 0 subnets: 000 WARNING: Disallowed subnets in virtual_private= is empty. If you have 000 private address space in internal use, it should be excluded! 000 000 algorithm ESP encrypt: id=2, name=ESP_DES, ivlen=8, keysizemin=64, keysizemax=64 000 algorithm ESP encrypt: id=3, name=ESP_3DES, ivlen=8, keysizemin=192, keysizemax=192 000 algorithm ESP encrypt: id=6, name=ESP_CAST, ivlen=8, keysizemin=40, keysizemax=128 000 algorithm ESP encrypt: id=7, name=ESP_BLOWFISH, ivlen=8, keysizemin=40, keysizemax=448 000 algorithm ESP encrypt: id=11, name=ESP_NULL, ivlen=0, keysizemin=0, keysizemax=0 000 algorithm ESP encrypt: id=12, name=ESP_AES, ivlen=8, keysizemin=128, keysizemax=256 000 algorithm ESP encrypt: id=13, name=ESP_AES_CTR, ivlen=8, keysizemin=160, keysizemax=288 000 algorithm ESP encrypt: id=14, name=ESP_AES_CCM_A, ivlen=8, keysizemin=128, keysizemax=256 000 algorithm ESP encrypt: id=15, name=ESP_AES_CCM_B, ivlen=8, keysizemin=128, keysizemax=256 000 algorithm ESP encrypt: id=16, name=ESP_AES_CCM_C, ivlen=8, keysizemin=128, keysizemax=256 000 algorithm ESP encrypt: id=18, name=ESP_AES_GCM_A, ivlen=8, keysizemin=160, keysizemax=288 000 algorithm ESP encrypt: id=19, name=ESP_AES_GCM_B, ivlen=12, keysizemin=160, keysizemax=288 000 algorithm ESP encrypt: id=20, name=ESP_AES_GCM_C, ivlen=16, keysizemin=160, keysizemax=288 000 algorithm ESP encrypt: id=22, name=ESP_CAMELLIA, ivlen=8, keysizemin=128, keysizemax=256 000 algorithm ESP encrypt: id=252, name=ESP_SERPENT, ivlen=8, keysizemin=128, keysizemax=256 000 algorithm ESP encrypt: id=253, name=ESP_TWOFISH, ivlen=8, keysizemin=128, keysizemax=256 000 algorithm ESP auth attr: id=1, name=AUTH_ALGORITHM_HMAC_MD5, keysizemin=128, keysizemax=128 000 algorithm ESP auth attr: id=2, name=AUTH_ALGORITHM_HMAC_SHA1, keysizemin=160, keysizemax=160 000 algorithm ESP auth attr: id=5, name=AUTH_ALGORITHM_HMAC_SHA2_256, keysizemin=256, keysizemax=256 000 algorithm ESP auth attr: id=6, name=AUTH_ALGORITHM_HMAC_SHA2_384, keysizemin=384, keysizemax=384 000 algorithm ESP auth attr: id=7, name=AUTH_ALGORITHM_HMAC_SHA2_512, keysizemin=512, keysizemax=512 000 algorithm ESP auth attr: id=8, name=AUTH_ALGORITHM_HMAC_RIPEMD, keysizemin=160, keysizemax=160 000 algorithm ESP auth attr: id=9, name=AUTH_ALGORITHM_AES_CBC, keysizemin=128, keysizemax=128 000 algorithm ESP auth attr: id=251, name=AUTH_ALGORITHM_NULL_KAME, keysizemin=0, keysizemax=0 000 000 algorithm IKE encrypt: id=0, name=(null), blocksize=16, keydeflen=131 000 algorithm IKE encrypt: id=5, name=OAKLEY_3DES_CBC, blocksize=8, keydeflen=192 000 algorithm IKE encrypt: id=7, name=OAKLEY_AES_CBC, blocksize=16, keydeflen=128 000 algorithm IKE hash: id=1, name=OAKLEY_MD5, hashsize=16 000 algorithm IKE hash: id=2, name=OAKLEY_SHA1, hashsize=20 000 algorithm IKE hash: id=4, name=OAKLEY_SHA2_256, hashsize=32 000 algorithm IKE hash: id=6, name=OAKLEY_SHA2_512, hashsize=64 000 algorithm IKE dh group: id=2, name=OAKLEY_GROUP_MODP1024, bits=1024 000 algorithm IKE dh group: id=5, name=OAKLEY_GROUP_MODP1536, bits=1536 000 algorithm IKE dh group: id=14, name=OAKLEY_GROUP_MODP2048, bits=2048 000 algorithm IKE dh group: id=15, name=OAKLEY_GROUP_MODP3072, bits=3072 000 algorithm IKE dh group: id=16, name=OAKLEY_GROUP_MODP4096, bits=4096 000 algorithm IKE dh group: id=17, name=OAKLEY_GROUP_MODP6144, bits=6144 000 algorithm IKE dh group: id=18, name=OAKLEY_GROUP_MODP8192, bits=8192 000 algorithm IKE dh group: id=22, name=OAKLEY_GROUP_DH22, bits=1024 000 algorithm IKE dh group: id=23, name=OAKLEY_GROUP_DH23, bits=2048 000 algorithm IKE dh group: id=24, name=OAKLEY_GROUP_DH24, bits=2048 000 000 stats db_ops: {curr_cnt, total_cnt, maxsz} :context={0,0,0} trans={0,0,0} attrs={0,0,0} 000 000 "L2TP-PSK-noNAT": 123.1.1.1<123.1.1.1>:17/1701...%any:17/%any; unrouted; eroute owner: #0 000 "L2TP-PSK-noNAT": myip=unset; hisip=unset; 000 "L2TP-PSK-noNAT": ike_life: 28800s; ipsec_life: 3600s; rekey_margin: 540s; rekey_fuzz: 100%; keyingtries: 3 000 "L2TP-PSK-noNAT": policy: PSK+ENCRYPT+PFS+IKEv2ALLOW+SAREFTRACK+lKOD+rKOD; prio: 32,32; interface: eth0; 000 "L2TP-PSK-noNAT": dpd: action:clear; delay:10; timeout:20; 000 "L2TP-PSK-noNAT": newest ISAKMP SA: #0; newest IPsec SA: #0; 000 "L2TP-PSK-noNAT"[2]: 123.1.1.1<123.1.1.1>:17/1701...123.2.2.2[10.0.0.231]:17/1701; unrouted; eroute owner: #0 000 "L2TP-PSK-noNAT"[2]: myip=unset; hisip=unset; 000 "L2TP-PSK-noNAT"[2]: ike_life: 28800s; ipsec_life: 3600s; rekey_margin: 540s; rekey_fuzz: 100%; keyingtries: 3 000 "L2TP-PSK-noNAT"[2]: policy: PSK+ENCRYPT+PFS+IKEv2ALLOW+SAREFTRACK+lKOD+rKOD; prio: 32,32; interface: eth0; 000 "L2TP-PSK-noNAT"[2]: dpd: action:clear; delay:10; timeout:20; 000 "L2TP-PSK-noNAT"[2]: newest ISAKMP SA: #1; newest IPsec SA: #0; 000 "L2TP-PSK-noNAT"[2]: IKE algorithm newest: AES_CBC_256-SHA1-MODP2048 000 000 #2: "L2TP-PSK-noNAT"[2] 123.2.2.2:55371 STATE_QUICK_R0 (expecting QI1); EVENT_CRYPTO_FAILED in 286s; nodpd; idle; import:not set 000 #1: "L2TP-PSK-noNAT"[2] 123.2.2.2:55371 STATE_MAIN_R3 (sent MR3, ISAKMP SA established); EVENT_SA_REPLACE in 28516s; newest ISAKMP; nodpd; idle; import:not set 000
ipsecvalidation
Checking if IPsec got installed and started correctly: Version check and ipsec on-path [OK] Openswan U2.6.41/K3.14.12-1-lts (netkey) See `ipsec --copyright' for copyright information. Checking for IPsec support in kernel [OK] NETKEY: Testing XFRM related proc values ICMP default/send_redirects [OK] ICMP default/accept_redirects [OK] XFRM larval drop [OK] Hardware random device check [N/A] Two or more interfaces found, checking IP forwarding [OK] Checking rp_filter [ENABLED] /proc/sys/net/ipv4/conf/eth0/rp_filter [ENABLED] Checking that pluto is running [OK] Pluto listening for IKE on udp 500 [OK] Pluto listening for IKE on tcp 500 [NOT IMPLEMENTED] Pluto listening for IKE/NAT-T on udp 4500 [OK] Pluto listening for IKE/NAT-T on tcp 4500 [NOT IMPLEMENTED] Pluto listening for IKE on tcp 10000 (cisco) [OK] Checking NAT and MASQUERADEing [TEST INCOMPLETE] Checking 'ip' command [OK] Checking 'iptables' command [OK] ipsec verify: encountered errors
CONFIGS：
/etc/ipsec.conf
version 2 config setup dumpdir=/var/run/pluto/ nat_traversal=yes virtual_private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12,%v6:fd00::/8,%v6:fe80::/10 protostack=netkey plutoopts="--interface=eth0" force_keepalive=yes keep_alive=60 conn L2TP-PSK-noNAT authby=secret pfs=yes auto=add keyingtries=3 ikelifetime=8h keylife=1h type=transport left=123.1.1.1 leftprotoport=17/1701 right=%any rightprotoport=17/%any dpddelay=10 dpdtimeout=20 dpdaction=clear
/etc/ipsec.secrets （由于安全原因，值更改为伪造的东西，但预共享密钥已经在客户端validation）
: RSA { # RSA 2192 bits mydomain.net Thu Jul 17 09:16:05 2014 # for signatures only, UNSAFE FOR ENCRYPTION #pubkey=0xf1f1f1 Modulus: 0xf1f1f1 PublicExponent: 0x03 # everything after this point is secret PrivateExponent: 0xf1f1f1 Prime1: 0xf1f1f1 Prime2: 0xf1f1f1 Exponent1: 0xf1f1f1 Exponent2: 0xf1f1f1 Coefficient: 0xf1f1f1 } # do not change the indenting of that "}" 123.1.1.1 %any: PSK "somereallylongstring"
/etc/xl2tpd/xl2tpd.conf
[global] ipsec saref = yes saref refinfo = 30 [lns default] ip range = 172.16.1.30-172.16.1.100 local ip = 172.16.1.1 unix authentication = yes require authentication = yes ppp debug = yes pppoptfile = /etc/ppp/options.xl2tpd length bit = yes
/etc/ppp/options.xl2tpd
login ms-dns 208.67.222.222 ms-dns 208.67.220.220 auth mtu 1200 mru 1000 crtscts hide-password modem name l2tpd proxyarp lcp-echo-interval 30 lcp-echo-failure 4
在/ etc / ppp / pap-secrets中
# Secrets for authentication using PAP # client server secret IP addresses * l2tpd "" *
/etc/pam.d/ppp
auth required pam_nologin.so auth required pam_unix.so account required pam_unix.so session required pam_unix.so