Умучился я с этим зверем. Поставлен OpenVPN-сервер 2.02 на фре 5.4. Линуксовым клиентом хожу без проблем. Все пингуется, во внутреннюю сетку на той стороне пускает. С WinXP - чертовщина какая-то. Коннектится нормально. Но ничего не пингуется. Файрвол виндовый с tun-интерфейса снят. Не помогает.

В логах с виндовой стороны все нормально:

Sat Sep 10 21:44:31 2005 us=533140 OpenVPN 2.0.2 Win32-MinGW [SSL] [LZO] built on Aug 25 2005
Sat Sep 10 21:44:31 2005 us=533374 IMPORTANT: OpenVPN's default port number is now 1194, based on an official port number assignment by IANA.  OpenVPN 2.0-beta16 and earlier used 5000 as the default port.
Sat Sep 10 21:44:31 2005 us=538076 Control Channel Authentication: using '../easy-rsa/keys/ta.key' as a OpenVPN static key file
Sat Sep 10 21:44:31 2005 us=538148 Outgoing Control Channel Authentication: Using 160 bit message hash 'SHA1' for HMAC authentication
Sat Sep 10 21:44:31 2005 us=552525 Incoming Control Channel Authentication: Using 160 bit message hash 'SHA1' for HMAC authentication
Sat Sep 10 21:44:31 2005 us=552613 LZO compression initialized
Sat Sep 10 21:44:31 2005 us=552881 Control Channel MTU parms [ L:1542 D:166 EF:66 EB:0 ET:0 EL:0 ]
Sat Sep 10 21:44:31 2005 us=569840 Data Channel MTU parms [ L:1542 D:1450 EF:42 EB:135 ET:0 EL:0 AF:3/1 ]
Sat Sep 10 21:44:31 2005 us=569943 Local Options String: 'V4,dev-type tun,link-mtu 1542,tun-mtu 1500,proto UDPv4,comp-lzo,keydir 1,cipher BF-CBC,auth SHA1,keysize 128,tls-auth,key-method 2,tls-client'
Sat Sep 10 21:44:31 2005 us=569974 Expected Remote Options String: 'V4,dev-type tun,link-mtu 1542,tun-mtu 1500,proto UDPv4,comp-lzo,keydir 0,cipher BF-CBC,auth SHA1,keysize 128,tls-auth,key-method 2,tls-server'
Sat Sep 10 21:44:31 2005 us=570031 Local Options hash (VER=V4): '504e774e'
Sat Sep 10 21:44:31 2005 us=570068 Expected Remote Options hash (VER=V4): '14168603'
Sat Sep 10 21:44:31 2005 us=575657 Socket Buffers: R=[8192->8192] S=[8192->8192]
Sat Sep 10 21:44:31 2005 us=575719 UDPv4 link local (bound): [undef]:1194
Sat Sep 10 21:44:31 2005 us=575743 UDPv4 link remote: хх.хх.хх.хх:1194
Sat Sep 10 21:44:31 2005 us=583680 TLS: Initial packet from хх.хх.хх.хх:1194, sid=33bbc461 6056f295
Sat Sep 10 21:44:31 2005 us=644309 VERIFY OK: depth=1, /C=RU/ST=Moscow_Region/L=Moscow/O=PMH/OU=VPN/CN=PMH_VPN_CA/emailAddress=<покоцано мной>
Sat Sep 10 21:44:31 2005 us=645790 VERIFY OK: nsCertType=SERVER
Sat Sep 10 21:44:31 2005 us=645828 VERIFY OK: depth=0, /C=RU/ST=Moscow_Region/L=Moscow/O=PMH/OU=VPN/CN=<покоцано>/emailAddress=<покоцано>
Sat Sep 10 21:44:31 2005 us=856398 Data Channel Encrypt: Cipher 'BF-CBC' initialized with 128 bit key
Sat Sep 10 21:44:31 2005 us=856479 Data Channel Encrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Sat Sep 10 21:44:31 2005 us=856561 Data Channel Decrypt: Cipher 'BF-CBC' initialized with 128 bit key
Sat Sep 10 21:44:31 2005 us=856595 Data Channel Decrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Sat Sep 10 21:44:31 2005 us=856855 Control Channel: TLSv1, cipher TLSv1/SSLv3 DHE-RSA-AES256-SHA, 1024 bit RSA
Sat Sep 10 21:44:31 2005 us=856922 [покоцано] Peer Connection Initiated with хх.хх.хх.хх:1194
Sat Sep 10 21:44:32 2005 us=991518 SENT CONTROL [покоцано]: 'PUSH_REQUEST' (status=1)
Sat Sep 10 21:44:33 2005 us=602 PUSH: Received control message: 'PUSH_REPLY,route 192.168.1.0 255.255.255.0,route 10.10.20.1,ping 10,ping-restart 120,ifconfig 10.10.20.10 10.10.20.9'
Sat Sep 10 21:44:33 2005 us=699 OPTIONS IMPORT: timers and/or timeouts modified
Sat Sep 10 21:44:33 2005 us=718 OPTIONS IMPORT: --ifconfig/up options modified
Sat Sep 10 21:44:33 2005 us=737 OPTIONS IMPORT: route options modified
Sat Sep 10 21:44:33 2005 us=20499 netsh interface ip set address "VPN01" static 10.10.20.10 255.255.255.252
ЋЉ.
Sat Sep 10 21:44:37 2005 us=405506 TAP-WIN32 device [VPN01] opened: \\.\Global\{7DC8A1B0-EC78-4F61-BDA4-3A72BB3FFA5E}.tap
Sat Sep 10 21:44:37 2005 us=405596 TAP-Win32 Driver Version 8.1
Sat Sep 10 21:44:37 2005 us=405624 TAP-Win32 MTU=1500
Sat Sep 10 21:44:37 2005 us=412571 Successful ARP Flush on interface [3] {7DC8A1B0-EC78-4F61-BDA4-3A72BB3FFA5E}
Sat Sep 10 21:44:37 2005 us=422694 TEST ROUTES: 0/0 succeeded len=2 ret=0 a=0 u/d=down
Sat Sep 10 21:44:37 2005 us=422751 Route: Waiting for TUN/TAP interface to come up...
Sat Sep 10 21:44:38 2005 us=555337 TEST ROUTES: 0/0 succeeded len=2 ret=0 a=0 u/d=down
Sat Sep 10 21:44:38 2005 us=555374 Route: Waiting for TUN/TAP interface to come up...
Sat Sep 10 21:44:39 2005 us=695874 TEST ROUTES: 0/0 succeeded len=2 ret=0 a=0 u/d=down
Sat Sep 10 21:44:39 2005 us=695911 Route: Waiting for TUN/TAP interface to come up...
Sat Sep 10 21:44:40 2005 us=842723 TEST ROUTES: 2/2 succeeded len=2 ret=1 a=0 u/d=up
Sat Sep 10 21:44:40 2005 us=842796 route ADD 192.168.1.0 MASK 255.255.255.0 10.10.20.9
Sat Sep 10 21:44:41 2005 us=191713 route ADD 10.10.20.1 MASK 255.255.255.255 10.10.20.9
Sat Sep 10 21:44:41 2005 us=372707 Initialization Sequence Completed

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Роутинг в виндах после коннекта выглядит так:

Сетевой адрес           Маска сети      Адрес шлюза       Интерфейс  Метрика
          0.0.0.0          0.0.0.0      192.168.0.1   192.168.0.100      20
       10.10.20.1  255.255.255.255       10.10.20.9     10.10.20.10      1
       10.10.20.8  255.255.255.252      10.10.20.10     10.10.20.10      30
      10.10.20.10  255.255.255.255        127.0.0.1       127.0.0.1      30
   10.255.255.255  255.255.255.255      10.10.20.10     10.10.20.10      30
        127.0.0.0        255.0.0.0        127.0.0.1       127.0.0.1      1
      192.168.0.0    255.255.255.0    192.168.0.100   192.168.0.100      20
    192.168.0.100  255.255.255.255        127.0.0.1       127.0.0.1      20
    192.168.0.255  255.255.255.255    192.168.0.100   192.168.0.100      20
      192.168.1.0    255.255.255.0       10.10.20.9     10.10.20.10      1
        224.0.0.0        240.0.0.0      10.10.20.10     10.10.20.10      30
        224.0.0.0        240.0.0.0    192.168.0.100   192.168.0.100      20
  255.255.255.255  255.255.255.255      10.10.20.10     10.10.20.10      1
  255.255.255.255  255.255.255.255    192.168.0.100   192.168.0.100      1
Основной шлюз:         192.168.0.1
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И ничего через VPN не пингуется. Где может быть засада?