Michael C
asked on
Cannot ping server suddenly
Hi Expert
We recently find around 2 PC having a symptom cannot connect to server SUDDENLY.
It may happen around every 3 months. It is strange that the PC can ping one of the server, while cannot ping others. Also the PC cannot get IP from DHCP. Below is the finding
3 Servers:
DC1 - 192.168.1.3 (Cannot ping, cannot access)
DC2 - 192.168.1.8 (Can ping)
Server 3 - 192.168.1.5 (cannot ping)
PC - Win10 and Win7
What I have tried
1. Windows update the PC
2. Restart PC, disable network interface, disable anti-virus on PC
3. Disable firewall on server
The ping message is "Destination host unreachable"
There is no problem on other PCs
Regards, M
We recently find around 2 PC having a symptom cannot connect to server SUDDENLY.
It may happen around every 3 months. It is strange that the PC can ping one of the server, while cannot ping others. Also the PC cannot get IP from DHCP. Below is the finding
3 Servers:
DC1 - 192.168.1.3 (Cannot ping, cannot access)
DC2 - 192.168.1.8 (Can ping)
Server 3 - 192.168.1.5 (cannot ping)
PC - Win10 and Win7
What I have tried
1. Windows update the PC
2. Restart PC, disable network interface, disable anti-virus on PC
3. Disable firewall on server
The ping message is "Destination host unreachable"
There is no problem on other PCs
Regards, M
bbao
are they VMs in a cloud, or just physical computers on a small office network?
ASKER
Physical PC in small office ... HP PC with domain 2016
can they always ping the router or default gateway?
ASKER
yes, can ping the gateway 192.168.1.254
on the hosts 1.3 and 1.5, open a Command Prompt window, then run the following commands, in sequence immediately after the previous command.
PING 192.168.1.8
ARP -A
PING 192.168.1.3
ARP -A
PING 192.168.1.5
ARP -A
PING 192.168.1.8
ARP -A
PING 192.168.1.3
ARP -A
PING 192.168.1.5
ARP -A
ASKER
I only see 1.8 dynamic address and mac
that means 1.3 and 1.5 are physically disconnected from the network. please check the network cable, socket and port, just all physical things.
ASKER
No, other PC can access 1.3 and 1.5
okay. can you paste the whole IPCONFIG /ALL results for 1.3, 1.5 and 1.8? thanks.
please paste the results as code like this.
check the following:
1. do you have VLANs on the ports?
2. do you have port security on the switch?
3. on the switch, do you have auto negotiate or ports set to certain speed? 100/1000
4. on other computers, can they ping them?
5. disable firewall / antivirus on the computer itself and test.
there are many causes, answering these questions may help identifying the issue
1. do you have VLANs on the ports?
2. do you have port security on the switch?
3. on the switch, do you have auto negotiate or ports set to certain speed? 100/1000
4. on other computers, can they ping them?
5. disable firewall / antivirus on the computer itself and test.
there are many causes, answering these questions may help identifying the issue
ASKER
Hi Sam,
For below, I did sometimes the PCs will negotiate to be 100MB speed, and sometimes is 1GB. Do you think this is the hints?
on the switch, do you have auto negotiate or ports set to certain speed? 100/1000
For below, I did sometimes the PCs will negotiate to be 100MB speed, and sometimes is 1GB. Do you think this is the hints?
on the switch, do you have auto negotiate or ports set to certain speed? 100/1000
you can try from the switch set the port to certain speed and check. what are the switches? are they managed or not managed?
ASKER
The switch is HP1920, I may try to update the firmware.
For the speed, should we setup it as 1GB instead of auto-negotiation? Most of our PC supports 1GB honestly.
For the speed, should we setup it as 1GB instead of auto-negotiation? Most of our PC supports 1GB honestly.
as mentioned above, try 1g or 100M and feedback
ASKER
Hi
I have tested that it is switch problem. I find the PC can only ping the device connected with the same switch.
If I put the server (cannot ping) to the same switch, then it can ping.
I tried to update the firmware, but no luck. Restart the switch, but no luck. The speed is normal (100MB).
So any hints on it?
Appreciate for any help
I have tested that it is switch problem. I find the PC can only ping the device connected with the same switch.
If I put the server (cannot ping) to the same switch, then it can ping.
I tried to update the firmware, but no luck. Restart the switch, but no luck. The speed is normal (100MB).
So any hints on it?
Appreciate for any help
ASKER
Also it is strange... when I plug the PC cable to another switch, it cannot work (cannot ping any)
check NAT and routing between switch’s ... also if you have firewall, check the rules.
ASKER CERTIFIED SOLUTION
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