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I have an Acer Aspire One netbook (722-0828), running Windows 7 Home Premium 64-bit.

When connected via ethernet cable, networking works normally.

When connected via wifi, IP works, ICMP works, DNS works:

C:\Users\Tony>ping google.com

Pinging google.com [74.125.225.196] with 32 bytes of data:
Reply from 74.125.225.196: bytes=32 time=27ms TTL=54
Reply from 74.125.225.196: bytes=32 time=24ms TTL=54
Reply from 74.125.225.196: bytes=32 time=36ms TTL=54
Reply from 74.125.225.196: bytes=32 time=28ms TTL=54

Ping statistics for 74.125.225.196:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 24ms, Maximum = 36ms, Average = 28ms

But I can't initiate any TCP connections from the windows machine to anywhere else. HTTP fails (tried IE, FF, Opera, and Chrome); PuTTY fails (telnet and ssh); ftp fails, DNS-over-TCP (nslookup with "set vc") fails.

Here, I can see that DNS-over-UDP is working, even to remote servers; that tells me that IP and UDP are both working. But as soon as I do set vc, the next lookup hangs:

C:\Users\Tony>nslookup
Default Server:  UnKnown
Address:  192.168.1.1

> acer.com
Server:  UnKnown
Address:  192.168.1.1

Non-authoritative answer:
Name:    acer.com
Address:  193.0.238.166

> acer.com 8.8.8.8
Server:  [8.8.8.8]
Address:  8.8.8.8

Non-authoritative answer:
Name:    acer.com
Address:  193.0.238.166

> set vc
> acer.com
Server:  UnKnown
Address:  192.168.1.1

^C
C:\Users\Tony>nslookup
Default Server:  UnKnown
Address:  192.168.1.1

> set vc
> acer.com 8.8.8.8
Server:  [8.8.8.8]
Address:  8.8.8.8

^C
C:\Users\Tony>

Other devices (OSX laptops, iOS devices, Android devices, other Windows laptops) work fine on the same wifi network.

Using a packet sniffer, I see that the windows machine sends the initial SYN packet, and my server replies with SYN+ACK... but the windows TCP stack never seems to see it, as there is no reply, and the windows machine eventually retries the connection with another SYN packet.

Troubleshooting attempts, none of which fixed the situation:

  1. Deleted / re-created both interfaces.

  2. Reset the ip stack on Windows.

  3. Disabled the Windows Firewall.

  4. Disabled IPv6 on the wifi interface.

  5. Confirmed the wifi network is identified as a "Home Network".

Any hints would be very welcome.

Here's the output of "ipconfig /all":

C:\Users\Tony>ipconfig /all

Windows IP Configuration

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

Ethernet adapter Local Area Connection:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Atheros AR8152/8158 PCI-E Fast Ethernet C
ontroller (NDIS 6.20)
   Physical Address. . . . . . . . . : DC-0E-A1-51-1C-1D
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

Wireless LAN adapter Wireless Network Connection:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Atheros AR5B125 Wireless Network Adapter
   Physical Address. . . . . . . . . : 60-D8-19-62-F4-0B
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IPv4 Address. . . . . . . . . . . : 192.168.1.170(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Wednesday, January 23, 2013 12:38:54 PM
   Lease Expires . . . . . . . . . . : Thursday, January 24, 2013 12:38:54 PM
   Default Gateway . . . . . . . . . : 192.168.1.1
   DHCP Server . . . . . . . . . . . : 192.168.1.1
   DNS Servers . . . . . . . . . . . : 192.168.1.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.{993CDEB4-B0C8-41FD-A3F1-DE951DB1FF9F}:

   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

Tunnel adapter Local Area Connection* 9:

   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. . . . . . . . . . . : 2001:0:9d38:6ab8:105c:25e6:3f57:fe55(Pref
erred)
   Link-local IPv6 Address . . . . . : fe80::105c:25e6:3f57:fe55%11(Preferred)
   Default Gateway . . . . . . . . . : ::
   NetBIOS over Tcpip. . . . . . . . : Disabled

Tunnel adapter isatap.{88C7FD80-32F0-4C45-9D1A-06EB7A869BB9}:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter #3
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
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Post the packet capture I the syn and syn-ack. Perhaps via Cloudshark.com –  Spiff Jan 24 '13 at 3:03
    
We know that the wifi is working in general, because your server was able to respond, so everthing must be right at layer 1. You saw the response packet, so layer 2 is working. Did you make sure the ethernet was disconnected when testing wifi? –  Paul Jan 24 '13 at 3:06
    
@Spiff -- I've posted a summary snapshot, as well as the fully-decoded packets. If some other format would be better, just let me know. Thanks! –  AnthonyFoiani Jan 24 '13 at 3:47
    
@Paul -- Yes, verified that it was unplugged (note Media Disconnected). Thanks for verifying my own observations w.r.t. lower layers. It looks like the inbound TCP sockets are just getting lost somewhere. I'll probably try to run a packet capture on the Windows side, to see if the SYN+ACK is making it back onboard. –  AnthonyFoiani Jan 24 '13 at 3:49
    
Sigh. "... the inbound TCP packets are just getting lost..." –  AnthonyFoiani Jan 24 '13 at 4:02
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