8

This is really strange - I have a workaround for this (read on), but I'd love to know why it works.

I had a VPN setup working fine with a WinServer2003 server and a Vista client.

Then I setup a new Win7 box to access the same server. The server is running WINS.

Both clients could get into the VPN fine, and ping machines on the server side by IP4 address.

But ONLY the Vista client could ping machines by NETBIOS address (machine name). The Win7 client just returned "could not find host".

As far as I can tell, the clients are configured identically.

By chance, while fiddling, I discovered that if I run a tracert on the Win7 client - tracing the route to any machine on the server side - then AFTER THAT the NETBIOS works.

For example (this is from the cygwin command line on the Win7 box, with redacted passwords, etc.):

$ rasdial "vpnName" Dave passWord
Connecting to vpnName.
Verifying username and password... 
Registering your computer on the network... 
Successfully connected to vpnName. Command completed successfully.

Dave@QUIET ~ 
$ ping henshaw 
Ping request could not find host henshaw. Please check the name and try again.

Dave@QUIET ~ 
$ tracert 10.1.10.1

Tracing route to www [10.1.10.1] over a maximum of 30 hops:

  1    39 ms    47 ms    49 ms  ASH [10.1.10.184]
  2    44 ms    31 ms    32 ms  www [10.1.10.1]

Trace complete.

$ ping henshaw

Pinging henshaw [10.1.10.92] with 32 bytes of data: 
Reply from 10.1.10.92: bytes=32 time=36ms TTL=127 
Reply from 10.1.10.92: bytes=32 time=46ms TTL=127
Reply from 10.1.10.92: bytes=32 time=35ms TTL=127
Reply from 10.1.10.92: bytes=32 time=41ms TTL=127

Ping statistics for 10.1.10.92:
   Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), 
Approximate round trip times in milli-seconds:
    Minimum = 35ms, Maximum = 46ms, Average = 39ms

(ASH is the Server2003 server box, 10.1.10.1 is the network gateway.)

What the heck is going on? Why does the Win7 box act differently in the first place, and why does tracert fix it?

--Dave


Added:

Per suggestion of @Sane, here is the ipconfig all output from both clients:

Vista box:

Dave@Tower ~
$ ipconfig /all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : Tower
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : home

PPP adapter vpnName:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : vpnName
   Physical Address. . . . . . . . . :
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 10.1.10.80(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.255
   Default Gateway . . . . . . . . . :
   DNS Servers . . . . . . . . . . . : 10.1.10.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . : home
   Description . . . . . . . . . . . : NVIDIA nForce 10/100/1000 Mbps Ethernet
   Physical Address. . . . . . . . . : 6C-F0-49-D1-92-FC
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::1d56:57b0:5c40:8ea2%10(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.1.11(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Tuesday, November 20, 2012 12:52:51 PM
   Lease Expires . . . . . . . . . . : Wednesday, November 21, 2012 12:52:50 PM
   Default Gateway . . . . . . . . . : 192.168.1.1
   DHCP Server . . . . . . . . . . . : 192.168.1.1
   DHCPv6 IAID . . . . . . . . . . . : 258797641
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-14-7D-F7-96-6C-F0-49-D1-92-FC
   DNS Servers . . . . . . . . . . . : 192.168.1.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter Local Area Connection* 6:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 7:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 02-00-54-55-4E-01
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2001:0:9d38:6ab8:93:2ec:3f57:fef4(Preferred)
   Link-local IPv6 Address . . . . . : fe80::93:2ec:3f57:fef4%11(Preferred)
   Default Gateway . . . . . . . . . : ::
   NetBIOS over Tcpip. . . . . . . . : Disabled

Tunnel adapter Local Area Connection* 11:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : home
   Description . . . . . . . . . . . : isatap.home
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Win7 box:

Dave@QUIET ~
$ ipconfig /all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : QUIET
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No

PPP adapter vpnName:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : vpnName
   Physical Address. . . . . . . . . :
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 10.1.10.108(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.255
   Default Gateway . . . . . . . . . :
   DNS Servers . . . . . . . . . . . : 10.1.10.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Intel(R) 82578DC Gigabit Network Connection
   Physical Address. . . . . . . . . : 00-1C-C0-F7-54-2F
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::3c6a:4873:97c:e773%10(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.1.110(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.1.1
   DHCPv6 IAID . . . . . . . . . . . : 234888384
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-17-C6-DC-78-00-1C-C0-F7-54-2F
   DNS Servers . . . . . . . . . . . : 192.168.1.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.{13A00E9E-CF57-4B02-B3F6-21929585E6FC}:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:400:32e2:9d91:5c30(Preferred)
   Link-local IPv6 Address . . . . . : fe80::400:32e2:9d91:5c30%12(Preferred)
   Default Gateway . . . . . . . . . : ::
   NetBIOS over Tcpip. . . . . . . . : Disabled

Tunnel adapter isatap.{B34461EA-B740-4553-A1A7-570852066611}:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
  • 3
    I don't have a solution for you, but why use WINS at all? It's evil; kill it with fire at your earliest opportunity. – HopelessN00b Nov 20 '12 at 18:36
  • That doesn't really make much sense to me. Have you considered firing up wireshark/tcpdump and performing a capture to see what else is going on while you run that that traceroute? – Zoredache Nov 20 '12 at 18:36
  • Check to see if the Win7 system has WINS set, it would probably also be helpful to have a ipconfig /all print out for both the Win7 and Vista systems. – Winter Faulk Nov 20 '12 at 18:38
  • @Sane See updated post. Neither client has WINS set. – nerdfever.com Nov 20 '12 at 18:58
  • Seems to be some kind of routing issue, when you try pinging the first time it doesn't know how to route to the ASH box but after a trace route it "learns" the route to the ASH server. I'd check routes on both the Win7 box before and after the tracert and routes on the vista box (as a note trace routes send ICMP packets to each hop in the path where ping send an ICMP packet directly to the host) – Winter Faulk Nov 20 '12 at 19:11
0

I suspect that a side-effect of the tracert command is that it is populating the NetBIOS name cache. Run the command:

nbtstat /c

Both before and after the tracert command. My guess is you'll see the entry for "henshaw" show up.

I forget the exact mechanism, it's something about being in an ad hoc NetBIOS network, there's no centralized name service so machines have to discover each other. Something tracert does while trying to do a reverse lookup of the IP address you supplied provokes a broadcast for NetBIOS names on the local LAN, and since your test box and "henshaw" are on the same network, your box can learn the name.

Try using "nbtstat /R" to flush the NetBIOS name cache, which should bring you back to the problem state. I think if you ping henshaw by its IP address, that will also populate the cache. Also, I suspect if you used "tracert /d" (don't resolve IP addresses into names) you won't get that beneficial effect.

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