What is the Command to check the connectivity of the router?

make sure that the network card gains an IP address from your router
, it should be configuerd for automatic IP then try this:
use ping command to check connectivity with router let us say the ip of your router is 192.168.1.1
the from command prompt use the command : ping 192.168.1.1
the router shoud reply , if so then make sure that configuration on your router is correct and no filtering roules enabled that puts your IP or MAC address in block mode.

1.Powercycle equipment ( Unplug power wait 15 seconds then plug back in. 2.Make sure connections are tight in to the router and to the modem. 3.Check you network settings Windows XP: Start/Run/Type ncpa.cpl and hit ok. Check and make sure that your connection doesnt say Connected Firewalled if it does to the left hand side you will see change windows firewall settings turn to off.If it doesnt say that double click the connection hit properties click on internet protocol and hit properties again,ensure that obtain ipaddress automatically is checked as well as obtain dns server automatically If not check them both and restart your computer. Windows Vista/7 Start/Search bar type ncpa.cpl right click on your connection and hit properties uncheck ipv6 and click on ipv4 and hit properties. After Ensure obtain ip address automatically is checked as well as Obtain DNS server automatically is checked restart computer. 4.Use command prompt: WIndows XP: Start/Run/Type cmd and hit ok Windows Vista/7 Start/All Programs/Accessories/Right Click Command Prompt and hit run as administrator. 5.Type in Command Prompt the Following Commands Each line is a seperate line is a new command simply press enter after each. netsh int ip reset reset.log netsh int ip delete arpcache netsh winsock reset ipconfig /flushdns 6.Restart Computer Final: If you still have issues connecting refer to router manufacture.

1.Ensure ethernet cord coming from modem is plugged directly into internet port of router.
2.Powercycle equipment (Unplug power from home modem and router wait 15 seconds then plug back in
3.Open Network Connections XP:Start/Run/Type ncpa.cpl
Vista/7 Start/Search bar/Type ncpa.cpl
4. A.Right click on wireless connection the connection you use with router and hit properties,
B.Uncheck Internet Protocol Version 6/ Click on Internet Protocol Version 4 and hit properties,
C.Ensure Obtain an ipaddress automatically is checked
Ensure Obain a DNS server automatically is checked as well
5.Open Command Prompt XP:Start/Run/Type cmd
Vista/7 Start/All Programs/Accessories/Right click on Command Prompt hit run as administrator.
6.Type in Command Prompt: netsh int ip reset reset.log (Hit Enter after each command)
netsh int ip delete arpcache
netsh winsock reset
ipconfig /flushdns
7.Restart Computer
8.If still unable to access internet Disable Firewalls/Antivirus

If the wireless connection is working fine it show that your internet security is fine and you can access net without problem
there could be a connection issues a within the cables
1) Connect the Ethernet cable to the Laptop and connect the other end to router E1.
2) Open the command windows (DOS ) by typing cmd or command on the Run option ..
START- RUN- type command then hit Enter
3) In the black command windows - Type IPCONFIG
c:\> IPCONFIG hit enter
it will provide with the correct IP ADDRESS and Gate Way Address
Check the gateway address - shout strat with 192.168.X.X
If it is not there is some problem -
4) Check the Device manager and check the Ethernet Adapter whether the adapter is enabled or Disables or Drivers are installed or not

If you can use the same cable and ethernet port to connect to the router with a laptop, or other computers, then you have isolated the problem to your non-connecting computer. Plug in the computer with the connection issue with the same ethernet cable. Next, open up command prompt and type in the command "ping 127.0.0.1". This command checks your NIC card to see if it is working properly (if you get "Reply from 127.0.0.1", then your NIC card is good, but if not, then you need to replace your NIC card.). If your NIC card is good, ping your default gateway (i.e. using a linksys with a default IP, type "ping 192.168.1.1" in command prompt) Your router's private IP Address, which can be found by successfully connecting another pc and, on the connected pc, typing "ipconfig" in command prompt, is also known as the default gateway. If you get 4 "Request timed out.", or "Reply from 169.X.X.X" ("X" being any number), then your network connection settings on your pc are incorrect. To fix these settings, assuming that you have DHCP enabled on both your router and the computer being troubleshooted, use the commands "ipconfig /release" and then "ipconfig /renew" in command prompt. Give the computer a minute or two to allow the computer time to acquire a new IP Address, and the correct configuration from your router. Now your computer should be connecting properly.

First you check the connectivity with your router and your pc also check your firewall and antivirus blockages.

to check connectivity use ping command from your command prompt

Start ->run->cmd enter
type ping space your router ip address then -t see its frequently replying.

Enable dhcp option in your router

The command to ping the router is ping 192.168.2.1. Both are to be executed from a command prompt.

The command to ping the router is ping 192.168.2.1. Both are to be executed from a command prompt.

The command to ping the router is ping 192.168.2.1. Both are to be executed from a command prompt.