Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I've just tried using two different ethernet switches on my network to replace an 8-port Netgear gigabit ethernet switch, which works fine, but doesn't have enough ports for what I need. Computers are connected to a TP-Link TD-8840T router via a switch. They use DHCP for IP address assignment.

One switch is a TigerSwitch 6924M, which I'd expect to be difficult to set up, since it is second hand and has an advanced configuration menu, which I can't access without a serial port. However, the second switch that I tried is a new TP-Link TL-SF024, which doesn't appear to have any configuration options, so that can't be the problem.

When I say "not working," I mean that although they display that they are connected to a network, they cannot access the internet. For example commands like "ping -c10 google.co.uk" come up with 100% packet loss.

What could be causing the problem and how do I fix it?

share|improve this question
    
Can computers on the LAN contact each other through the switch(es)? –  Ƭᴇcʜιᴇ007 Sep 21 '12 at 15:45
    
nmap -sn 192.168.1.1/24 doesn't reveal any live hosts, which I imagine it should do if the computers can connect to each other through the LAN? –  Froskoy Sep 21 '12 at 15:55
    
Have you just tried pinging other systems/IP addresses on the LAN? –  Ƭᴇcʜιᴇ007 Sep 21 '12 at 15:57
    
Just tried plugging the TL-SF024 in via the Netgear switch and for some reason everything works. I can ping other computers on the network and connect to the internet. Any ideas why this would happen? The TigerSwitch still doesn't work, but I guess I need to set this up more carefully. –  Froskoy Sep 21 '12 at 16:22

1 Answer 1

up vote 0 down vote accepted

Start with basic network troubleshooting:

  • Are all cables connected properly and show link status up?
  • Did the computer receive an IP address from the DHCP server? (ipconfig /all)
  • Can the computer ping other computers on the same switch by IP address?
  • Can the computer ping the router by IP address?
  • Can the computer ping the IP address 8.8.8.8?
  • Does nslookup www.google.com return a result?
  • Does nslookup www.google.com NAMESERVER_IP_ADDRESS against each nameserver shown by ipconfig /all return a result?
  • Do problems persist after you deleted the DNS cache? (ipconfig /flushdns)
share|improve this answer
    
Thanks. It now works, but I don't know what the problem was. –  Froskoy Sep 23 '12 at 12:50

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.