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I have a TCP connection issue as follows.

The setup:

VMWare Virtual Machine: Windows Server 2008 R2 DataCenter SP1, IP: 192.168.2.111, DG: 192.168.2.254 Host Machine: Windows 7 Professional SP1, IP: 192.168.2.152, DG: 192.168.2.254

  • Firewall disabled on both machines

  • Virtual Machine Setting Network Adapter = Bridged Mode

  • No ip address or mac address clash ("arp -a" looks OK for this mapping)

  • Wireshark running on both VM and host machine

Linux Box 2.6.18-194.e15, IP: 10.1.0.120, DG: 10.1.0.254

  • Firewall disabled

VM and Linux box on different subnets but all traffic passed through default gateway (192.168.2.254 & 10.1.0.254) in both directions OK

The Issue:

Can't make TCP connection from Linux box to VM

On Linux box if I do: traceroute -T 192.168.2.111 -p5066

the SYN messages are picked up on the Wireshark running on the Host Machine (192.168.2.152) and not on the VM (192.168.2.111) so they don't reach the VM.

There is definitely an application on 192.168.2.111 listening for TCP on port 5066 so it would respond if the SYN got to the VM.

I can ping 192.168.2.111 from Linux and I can do traceroute -I 192.168.2.111 (which uses ICMP like ping) but TCP doesn't work.

I can make a TCP connection the other way from the VM to the Linux box so I don't think there's any issue with the mapping between the virtual network adpater and the host physical network adapter.

The VM can ping itself if I ping 127.0.0.1, the VM and the host can ping each other and I can file browse in both directions between the VM and the host.

I have uninstalled and reinstalled the network adapter on the VM and also TCP/IP for IPv4 and still no luck.

Any suggestions for other things to try ?

Thanks

  • 1
    A very detailed first post, thanks for that. Can you elaborate a little more on what router you are using? Are there any firewall rules between subnets? – Alex Berry Aug 7 '14 at 14:39
  • 3
    Some similar problems have turned out to be caused by dysfunctional TCP checksum offloading. So disabling TCP checksum offloading would be worth trying. Though I must say the symptoms sounds a bit more like a firewall problem than a TCP checksum offloading problem. – kasperd Aug 7 '14 at 14:58
  • Thanks kasperd, disabling the TCP checksum offloading works. Thanks very much. – user3416108 Aug 7 '14 at 17:01

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