Windows 7和8.1无法连接到Ubuntu22上的strongSwan 5.9VPN服务器

Question

我使用Ubuntu22.04和strongSwan 5.9.5在Oracle的OCI上设置了VPN服务器。当我尝试从不同的公路战士连接时，安卓运行良好，Win10工作良好，甚至古老的Blackberry10运行良好，但对于Win7和Win8.1笔记本电脑则不然:它们停留在第一阶段：

mytestcloud charon[968]: 05[NET] received packet: from <MYIP>[500] to 10.0.0.64[500] (616 bytes)
mytestcloud charon[968]: 05[ENC] parsed IKE_SA_INIT request 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) V V V V ]
mytestcloud charon[968]: 05[IKE] received MS NT5 ISAKMPOAKLEY v9 vendor ID
mytestcloud charon[968]: 05[IKE] received MS-Negotiation Discovery Capable vendor ID
mytestcloud charon[968]: 05[IKE] received Vid-Initial-Contact vendor ID
mytestcloud charon[968]: 05[ENC] received unknown vendor ID: 01:52:8b:bb:c0:06:96:12:18:49:ab:9a:1c:5b:2a:51:00:00:00:02
mytestcloud charon[968]: 05[IKE] <MYIP> is initiating an IKE_SA
mytestcloud charon[968]: 05[IKE] <MYIP> is initiating an IKE_SA
mytestcloud charon[968]: 05[CFG] selected proposal: IKE:AES_CBC_256/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
mytestcloud charon[968]: 05[IKE] local host is behind NAT, sending keep alives
mytestcloud charon[968]: 05[IKE] remote host is behind NAT
mytestcloud charon[968]: 05[IKE] sending cert request for "C=<MYCOUNTRY>, O=<MYFIRM>, CN=<MYNAME>"
mytestcloud charon[968]: 05[ENC] generating IKE_SA_INIT response 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) CERTREQ N(CHDLESS_SUP) N(MULT_AUTH) ]
mytestcloud charon[968]: 05[NET] sending packet: from 10.0.0.64[500] to <MYIP>[500] (345 bytes)
mytestcloud charon[968]: 08[IKE] sending keep alive to <MYIP>[500]
mytestcloud charon[968]: 09[JOB] deleting half open IKE_SA with <MYIP> after timeout

我的ipsec.conf是：

config setup
    charondebug="ike 1, knl 1, cfg 1"
    strictcrlpolicy=no
    # uniqueids = no

conn %default
   ikelifetime=24h
   keylife=24h
   keyexchange=ikev2
   dpdaction=clear
   dpdtimeout=3600s
   dpddelay=3600s
   compress=yes
   leftfirewall=yes
   left=%any
   leftsubnet=0.0.0.0/0
   right=%any
   rightsourceip=192.168.2.100/28
#   rightdns=8.8.8.8, 8.8.4.4
#   leftsendcert=always
#   fragmentation=yes
#   rightsendcert=never
#   forceencaps=yes
   rekey=no
   auto=add
   ike=aes256-sha1-modp1024,3des-sha1-modp1024!
   esp=aes256-sha1,3des-sha1!

conn roadwarrior
   leftauth=pubkey
   leftcert=VPNCert.pem
   leftid=<SERVERIP>
   rightauth=pubkey

状态是(Win10膝上型计算机连接)：

ubuntu@mytestcloud:~$ sudo ipsec statusall
Status of IKE charon daemon (strongSwan 5.9.5, Linux 5.15.0-1025-oracle, aarch64):
  uptime: 36 minutes, since Dec 12 09:05:21 2022
  malloc: sbrk 2605056, mmap 0, used 1670848, free 934208
  worker threads: 11 of 16 idle, 5/0/0/0 working, job queue: 0/0/0/0, scheduled: 2
  loaded plugins: charon pkcs11 aes des rc2 sha2 sha1 md4 md5 mgf1 random nonce x509 revocation constraints pubkey pkcs1 pkcs7 pkcs8 pkcs12 pgp dnskey sshkey pem openssl fips-prf gmp curve25519 xcbc cmac hmac ccm gcm drbg curl attr kernel-netlink resolve socket-default farp stroke vici updown eap-identity eap-aka eap-aka-3gpp2 eap-md5 eap-gtc eap-mschapv2 eap-dynamic eap-tls eap-ttls eap-peap eap-tnc xauth-generic tnc-tnccs dhcp counters
Virtual IP pools (size/online/offline):
  192.168.2.100/28: 11/1/0
Listening IP addresses:
  10.0.0.64
Connections:
 roadwarrior:  %any...%any  IKEv2, dpddelay=3600s
 roadwarrior:   local:  [<SERVERIP>] uses public key authentication
 roadwarrior:    cert:  "C=<MYCOUNTRY>, O=<MYFIRM>, CN=<SERVERIP>"
 roadwarrior:   remote: uses public key authentication
 roadwarrior:   child:  0.0.0.0/0 === dynamic TUNNEL, dpdaction=clear
Security Associations (1 up, 0 connecting):
 roadwarrior[3]: ESTABLISHED 7 minutes ago, 10.0.0.64[150.136.154.215]...<MYIP>[C=<MYCOUNTRY>, O=<MYFIRM>, CN=Win10]
 roadwarrior[3]: IKEv2 SPIs: 250f9e9db620a7e7_i 29b6ebbdb66a922a_r*, rekeying disabled
 roadwarrior[3]: IKE proposal: AES_CBC_256/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
 roadwarrior{1}:  INSTALLED, TUNNEL, reqid 1, ESP in UDP SPIs: c084f973_i 5daafdba_o
 roadwarrior{1}:  AES_CBC_256/HMAC_SHA1_96, 30958 bytes_i (122 pkts, 80s ago), 14517 bytes_o (50 pkts, 80s ago), rekeying disabled
 roadwarrior{1}:   0.0.0.0/0 === 192.168.2.100/32

我怀疑，这是某种碎裂问题，因为在添加

fragmentation=no

在ipsec.conf中，Win10设备以非常相同的方式下降。我补充说，一切都是必需的，我的意思是

net/ipv4/ip_no_pmtu_disc=1

在sysctl.conf和

FORWARD -t mangle --match policy --pol ipsec --dir in -o enp0s3 -p tcp -m tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1361:1536 -j TCPMSS --set-mss 1360

在iptable的规则中。请记住，我可以使用几乎相同的配置在Ubuntu16.04/ strongSwan 5.2.2上的AWS没有任何问题。不同的是默认密码套件和不同的服务器证书。那么，我能用某种方式将那些Windows野兽连接起来吗？

Answer 1

嗯，问题似乎是数据包碎片。一方面，我认为甲骨文已经将碎片硬编码到它的公共接口中；另一方面，遗留的Windows OSes (Windows7、Windows8/8.1、Windows10Pre1803、Ubuntu 16)不支持碎片化。因此，没有任何方法可以使用这种OSes上的客户端连接运行在Oracle上的strongSwan。有三种解决办法可以克服这一限制：

1. 远离遗留客户端(对于使用这些客户端的人来说不是很令人印象深刻)。
2. 变更云提供商--我在Amazon和DigitalOcean上测试了DigitalOcean:一切都完美无缺。
3. 改变VPN类型-就我个人而言，我以这个解决方案结束: WireGuard在Oracle上没有任何问题。我解决了DNS泄漏的问题，作为一个很好的补充。