Go through the following list to troubleshoot your internet connection. If you can answer yes, move down to the next one.
1. Is your ethernet card detected?
Run /sbin/ifconfig and see if 'eth0' is showing. If it isn't you probably don't have the correct driver installed.
2. Has it been assigned a name (i.e. eth0 or eth1)?
If not, try to find the correct driver in your drivers list and do modprobe driver name.
3. Do you have an ip address (do: /sbin/ifconfig at the prompt)?
If not, and you want to have a dynamic address, do:
dhclient eth0
-OR-
dhcpcd eth0
If neither of these work, you need to install a dhcp client. If you have them installed and for some reason get an error when you try to run these commands, you may have a misconfigured DHCP server.
If you want a static IP address, do:
/sbin/ifconfig eth0 up 192.168.0.2 [<-sub your desired IP address here]
4. Can you ping your gateway?
If you have an IP address and you can't ping your gateway you may have problems with the following:
Your IP address is incompatible with your gateway's local subnet. For example, your gateway may be: 192.168.0.1 and you may have set up your computer's IP address to be 192.168.1.2. You would need to change your computer's IP address to be 192.168.0.2. HINT: If you are using dynamic ip addressing, this is almost certainly not your problem!
-OR-
Your ethernet card or cable could just simply not be working. If possible, replace them.
5. Is there anything in /etc/resolv.conf? If not, you will need a DNS server listed... usually your gateway/router's local network address will suffice.
Again, if you're using dynamic ip addressing, this should not be a problem. If, however, you are using static IP addressing, add the following in your resolv.conf file (if empty or correct it):
domain domainName.tld
nameserver 192.168.0.0 [<- dns server #1 you can use your router's ip address if needed]
nameserver 192.168.0.1 [<- dns server #2 if you have one.]
6. Still not working? Run the following:
route add default gateway eth0
7. Is your gateway/router connected to the internet?
From your gateway/router, ping internet addresses like:
www.google.com or
www.yahoo.com
8. Does your gateway/router have an internet address? You can check it on the STATUS tab if you're using a Linksys router or if you're using another Linux machine as a router, you can do /sbin/ifconfig like in step 3
9. Can you ping the gateway/router's internet address from your computer?
If your gateway/router does have an internet address, then ping that internet address from your computer. If this doesn't work, repeat step #6, if this still doesn't do it, you most likely have ISP problems.
10. From your computer or your gateway/router can you ping the internet DNS servers listed?
If you cannot ping the internet DNS servers from either your router/gateway or your computer, your ISP is almost certainly having some DNS issues.
Hopefully this helps. If anyone has some suggestions or corrections, please post them.
