networking - Connection fails after one packet, server is unreachable by some clients while reachable by others
2014-04
Moha
I am clueless about this issue. I have a machnine with Windows 2003 Server R2. From time to time the following issue arises:
- The server is accessible from certain clients
- From other clients (on the same network) it is unreachable and when I ping it the first packet gets a reply but only the first, the rest gets a ping timeout. If I continue pinging, no packet gets any reply. However if I try the ping a few minutes later, the first packet gets a reply again, then silence.
- All the while the server is readily accessible from some clients
- The same "only one ping reply" happens if I try to ping from the server, again, some machines can be accessed, but some not.
It is totally random which connection is working and which is not. It looks like some kind of routing issue, but I already tried the following, without any luck:
- I changed the UTP cables
- I plugged the server into a different port on the switch
- I reinstalled the NIC driver on the server
- I switched off the firewalls on the clients
Sometimes it helps if I disable then enable the NIC on the server, sometimes it doesn't help.
The strangest thing is that this issue is recurring: it arises, then a few days later it disappears, then it arises again after a few weeks.
With the help of suggestions below, I traced down the issue to a colleague's android phone. Now I only want to know how did the packets got sent to the phone's MAC address when the IP of the phone was delegated by the DHCP and was different than the server's.
Mnebuerquo
NIC seems to be working, as windows detects the hardware and has a driver and reports success. DHCP seems to have gotten an ip address, 192.168.1.101. I released and renewed it and it seemed to work normally.
Edit: It's a Broadcom NetXtreme 57xx Gigabit Controller. /Edit
Edit: I can ping 192.168.1.101 (the offending machine) from other machines on the network, so I know the NIC is not broken. /Edit
Edit: Uninstalled/reinstalled NIC in device manager, nothing different. /Edit.
I tried ping 127.0.0.1 as first step of testing network configuration. Pinging 127.0.0.1 with 32 bytes of data: PING: transmit failed, error code 1.
I read somewhere that net helpmsg [error code] would give a human readable name for the error code. net helpmsg 1 says "Incorrect function"
I've tried disabling the firewall and antivirus in McAfee SecurityCenter and I still get the same error. Could the firewall/antivirus be breaking it even if disabled?
Broadcom Advanced Control Suite 2 is installed, and its network test passes all tests, including ping 192.168.1.1 which is the default gateway. If I try ping 192.168.1.1 from the command prompt I get the error code 1 again.
So does anyone have any theories that would explain this problem? Other tests I should try?
Thanks!
Mnebuerquo
The McAfee program was lying to me. I told it to disable the firewall and antivirus, but it was still blocking programs from accessing the internet. So when I tried ping with the firewall supposedly turned off, ping still failed.
The answer is to look at the Internet Application List under Personal Firewall Plus in the Security Center. There will be a list of programs which have used the internet and whether they are blocked or allowed.
Among the blocked programs were Internet Explorer and ping.exe. Changing the incorrectly blocked programs back to allowed fixed the problems.
The real problem was McAfee's program reporting that their firewall was disabled when it was still blocking access. This cost me over 4 hours and a headache today. Thanks McAfee!
Slomgiester
Have you tried re-installing the TCP/IP stack? Have you checked to make sure your ping.exe is not infected?
Pulse
If there is a firewall on the pc than it may be preventing ping. I'd disable any security software for the duration of the test. I'd also check the status of the NIC in device manager, just to make sure there are no driver errors