IP address - networking help

exup

Seen a few posts with problems with IP addressing and network problems

Haven't found any guide on here so have doen this one - hope it helps someone out. (if theres something already like this then please delete the post - sorry)

This is mainly based around a simple home network with a router (wireless or wired)- not the larger office networks (hopefully you will have your own network techs who can sort that).

You may have a problem with lack of internet connectivity - or an ip conflict somewhere.

The first thing to check is that the cable is plugged in to the PC (or laptop) and to the router / modem.

Also that the router /modem is ON sounds simple but justa case of a knocked plug can be overlooked.

Checking the IP address info
Go to START > RUN > type in cmd.
This should open small dos window. Type in ipconfig and press enter
You should now see:
IP address, Subnet Mask and Default Gateway.

The IP address is the address of the PC you are using. if you are connected to a router then this is usally 192.168.1.100 (the 100 may be a different number but its the first 3 sets of number we are worried about here)
If you are connected to a modem then your IP address may be different - but as long as something is displayed there. If you have more than one PC connected on the network then they will need different IP addresses - or you will get a conflict.

Subnet mask - 255.255.255.0 - again its the first 3 sets of number we are worried about here . and again on a modem this may be different.

Default Gateway : 192.168.1.1 If you are using a souter- then the first 3 sets of number should match the IP address above. If they don't then this will cause a problem.

For example
IP address 192.168.1.100
subnet mask 255.255.255.0
Default Gateway 192.168.2.1
will cause a connection problem may be sorted by changing the IP address to 192.168.2.100

The default gateway usually the IP address of your router itself. and typing in the url http://192.168.1.1 may even open your router browser control panel, even if connection to the internet is down.


Modifying IP settings
Go to START > Control Panel > Network Connections
Right click on the connection you use (make sure it isn't disabled this itself could be the problem - if it is then select enable)
Select properties then scroll down to Internet Protocol TCP/IP.
Select properties.

If the option "obtain an IP address automatically" is selected then you are running DHCP and the PC is hopefully assigned an IP address by your router or a DHCP server when connection is first set up. If you have an ip conflict with this option - try resetting your PC - and the router .

Use the following IP address - selecting this will allow you to manually edit the IP address of your PC.
So if you have an IP conflict you may be able to correct it here.
lets say the the router / default gateway address is192.168.1.1.
then the subnet mask should be 255.255.255.0
The first 3 sets of numbers of the IP address will be 192.168.1 and then you can enter any number you want between 1 and 254 . but not one thats already being used such as the default gateway IP or another PC on the network. (something like 192.168.1.100)

Click OK - then close

if you are going to check the ip address with the cmd dos window (as above). then you may need to close the dos window and open a new one

hope this may be of some help .

M4RKM

good post.. i'm sure it will come in useful