Find ip address on small network

dvdfan

Hello,

Im trying to find the ip address of another computer on a network. Well to explain properly its actually a dvd recorder that records security camera's and it can be setup to access the footage via my computer by typing in the ip address. My newtork is setup as follows:

1) Office Computer Downstairs
2) Point Of Sale Computer upstairs
3) Recording System Office Downstairs

Currently i have esat broadband, i have both computers 1 & 2 networked by connecting them to the broadband modem Netopia 3347wg (i know this is an eircom modem but i changed over and still use the eircom modem and it works fine) There are 4 ports on the back so i now have the recording system connected to the modem now as well. Im sure its something similar to finding the ip address of a printer on the network. Ive went in through the recording system setup and it showed these ethernet settings:

ip address 192.168.000.100
subnet mask 255.255.255.000
gateway 000.000.000.000

i presume these are default settings and i have to program the settings in once i find them out??

I tried pinging that address from the office pc and got no response but it defaulted to 192.168.0.100 instead of 192.168.000.100 so thats whats making me think its just a default address.

The manual for the recorder isnt helpful, just says to enter in the ip address into the networked computers browsers something like this http://192.168.1.100 but dosent give instructions on how to find the ip address

So in summary how do i find the ip address of other computers on my network??

Kali

From the windows command line: ipconfig /all will show you your IP.

Depending on your setup either your netopia box or a windows computer is acting as a dhcp server, giving out IP addresses to other devices... so you can either manually set the dvd recorder, or set it to automatically retrieve an IP.

Alternatively use an application like ipscan (angry ip scanner) to scan for devices and what IPs they are using.

Yakuza

If your devices are on different subnets, then that's why they can't see each other.

According to your post, the recorder's ip address 192.168.0.100, with a subnet mask of 255.255.255.0

Check the IP address of the PC you're trying to connect to the recorder with. It must be of the form 192.168.0.x (x can be any value from 1 to 254) to be able to see your recorder.

If you're using the Netopia as a DHCP server, then more than likely your address will be of the form 192.168.1.x, so your devices are on different logical networks (subnet) and can't see each other.

Basically, a subnet mask of 255.255.255.0 means that the first three sets of numbers (of four) in the IP address must be the same, otherwise they will be invisible to each other

(google "Subnet masking" for a proper explaination of how this works).

If the IP address of the recorder is configurable, you might have to (temporaily) change the range of the addresses given out by your Netopia box to match the subnet of the recorder.

Once this is done, you can probably tell the recorder what Ip address range to use, so set it and your dhcp server back to 192.168.1.x.

If the IP address is not configurable, then you'll have to permanently change the addresses given out by the netopia.

If you'd rather not go fiddling with the netopia, you could borrow a laptop and a "cross-over" cable and connect the laptop to the recorder directly. Set the IP address of the laptop's network card to 192.168.0.200 (so it's in the same subnet as the recorder) and then you should be able to reach its web interface. Once there, change the IP address to 192.168.1.(something) and reconnect it to the regular network, it should be visible now.


Hope this helps.

deathcrow

Your Network card operates at the bottom layer of the TCPIP Stack , it has a burned in hardware address called the MAC address , each device on your network will have a unique mac address .

When one pc trys to connect to another pc it sends out a broadcast ( hello is MAC blah blah in the room ) .

All the computers that do not have this MAC do not reply , the one that does replys ( Yo i am here ) , then the conection is established and the communications begin .

What am i on about you say ?

During all this time a certain amount of network traffic is generated and all the responses from various pieces of equipment are stored in a local MAC address cache , know as the ARP TABLE .

On a windows PC to view the ARP table simply go to a command prompt and type

ARP -A

You can type

ARP -d

to clear out the ARP cache .

An Example of the ARP table on my pc is below , this shows all recent broadcast traffic stored on my PC

10.5.0.99             00-09-97-cb-ce-02     dynamic
10.5.0.103            00-08-74-ad-01-e4     dynamic
10.5.0.195            00-14-22-1c-8a-1d     dynamic
10.5.0.206            00-11-25-a6-08-e6     dynamic
10.5.0.210            00-14-22-1b-fb-65     dynamic
10.5.0.211            00-14-22-1b-fb-3b     dynamic

The first column is the IP address , 2nd is the MAC address . Third states that the IP address was dynamically assigned .
Hope this helps ?

dvdfan

Yakuza wrote:

If your devices are on different subnets, then that's why they can't see each other.

According to your post, the recorder's ip address 192.168.0.100, with a subnet mask of 255.255.255.0

Check the IP address of the PC you're trying to connect to the recorder with. It must be of the form 192.168.0.x (x can be any value from 1 to 254) to be able to see your recorder.

If you're using the Netopia as a DHCP server, then more than likely your address will be of the form 192.168.1.x, so your devices are on different logical networks (subnet) and can't see each other.

Basically, a subnet mask of 255.255.255.0 means that the first three sets of numbers (of four) in the IP address must be the same, otherwise they will be invisible to each other

p.s i tried to change the recorder ip address via the setup menu on the recorder but it wont allow me to change them

(google "Subnet masking" for a proper explaination of how this works).

If the IP address of the recorder is configurable, you might have to (temporaily) change the range of the addresses given out by your Netopia box to match the subnet of the recorder.

Once this is done, you can probably tell the recorder what Ip address range to use, so set it and your dhcp server back to 192.168.1.x.

If the IP address is not configurable, then you'll have to permanently change the addresses given out by the netopia.

If you'd rather not go fiddling with the netopia, you could borrow a laptop and a "cross-over" cable and connect the laptop to the recorder directly. Set the IP address of the laptop's network card to 192.168.0.200 (so it's in the same subnet as the recorder) and then you should be able to reach its web interface. Once there, change the IP address to 192.168.1.(something) and reconnect it to the regular network, it should be visible now.


Hope this helps.

ipconfig all gave me this

ip 192.168.1.34
subnet 255.255.255.0
dhcp 192.168.1.254

to access my broadband settings i enter http://192.168.1.254 so i presume the modem is my dhcp server

My recorders ip is 192.168.000.100 so as you said they cannot see eachother and my 2 computers connected the modem are set to configure ip address automatically, so where in the modem settings can i change the computers to a different ip address to see the recorder without losing the network that already exists??

also i notice that there is 3 digits in the 3rd subnet of the recorders address and only 1 on the computer

eg:
192.168.1.34
192.168.100.34

does this make a difference. Anywho whats my best options here, if you want i can post screenshots of the settings if you let me know where to look in the dchp server settings and you can advise what to change. Thanks for taking the time to help me:)

p.s it wont allow me to change the ip address of the recorder via the setup menu

petes

What make is the recorder?

dvdfan

petes wrote:

What make is the recorder?

Mitsubishi Digital Recorder Model DX-NT400E

petes

Have you used the Nethunter software, and followed all the setup instructions for this recorder here?

Not sure as I haven't read the manual fully but it looks like you have to change the ip address on the unit itself. See page 52 of the pdf.

deathcrow

dvdfan wrote:

ipconfig all gave me this

ip 192.168.1.34
subnet 255.255.255.0
dhcp 192.168.1.254

to access my broadband settings i enter http://192.168.1.254 so i presume the modem is my dhcp server

My recorders ip is 192.168.000.100 so as you said they cannot see eachother and my 2 computers connected the modem are set to configure ip address automatically, so where in the modem settings can i change the computers to a different ip address to see the recorder without losing the network that already exists??

also i notice that there is 3 digits in the 3rd subnet of the recorders address and only 1 on the computer

eg:
192.168.1.34
192.168.100.34

does this make a difference. Anywho whats my best options here, if you want i can post screenshots of the settings if you let me know where to look in the dchp server settings and you can advise what to change. Thanks for taking the time to help me:)

p.s it wont allow me to change the ip address of the recorder via the setup menu

They are on different subnets ( you can tell by the 255.255.255.0 part ) .

You will need to log onto the modem ( dhcp server ) and change the dhcp scope to the same subnet as the camera .

I.E. create a scope 192.168.100.150 - 192.168.100.200 .

dvdfan

tried installing that nethunter but it said it was missing files and didnt install properly. I have that manual already but i just noticed it said that the you must stop recording to change the ip address so ill try that

So changing the ip address

from 192.168.000.100

to 192.169.100.100

Will that be compatible with my other pc on 192.168.1.34

whats the story with the 3rd block of numbers, my computer has only 1 digit and the recorder has 3 digits eg 100, is there any difference between 1 and 100??

ressem

Page 52 as mentioned, or page 31 of the manual here
http://www.bdt.co.nz/security/data/manual/dx-nt400e_manual.pdf

Yes there is a difference between 192.168.100.34 and 192.168.1.34
192.168.1.34 is the same as 192.168.001.034

Just make sure that you check that the new ip that you choose is not already used by another device. Just because you can't ping it does not mean that it isn't already used. The router will usually have a set section of the 192.168.1.x range for allocation by DHCP, and your recorders ip should be outside this address range.
Something like 192.168.1.250, (lowest you can use is 192.168.1.001 and highest is 192.168.1.253.)

Edit-
No
from 192.168.000.100

to 192.169.100.100
will not work.
For your setup the first, second and third numbers must be the same
That means 192.168.1.<something>, same as your router and computer.

deathcrow

the first three octets of the IP address MUST be the same

192.168.0.1
192.168.0.2

can talk to each other

192.168.0.3
192.168.100.3

Cannot

This is because of the subnet mask 255.255.255.0 <-- the first three are the network address and must be the same .

if it was 255.255.0.0 then they would be able to talk to each other . sorry if i am being over techy about it !

dvdfan

ressem wrote:

Page 52 as mentioned, or page 31 of the manual here
http://www.bdt.co.nz/security/data/manual/dx-nt400e_manual.pdf

Yes there is a difference between 192.168.100.34 and 192.168.1.34
192.168.1.34 is the same as 192.168.001.034

Just make sure that you check that the new ip that you choose is not already used by another device. Just because you can't ping it does not mean that it isn't already used. The router will usually have a set section of the 192.168.1.x range for allocation by DHCP, and your recorders ip should be outside this address range.
Something like 192.168.1.250, (lowest you can use is 192.168.1.001 and highest is 192.168.1.253.)

Edit-
No
from 192.168.000.100

to 192.169.100.100
will not work.
For your setup the first, second and third numbers must be the same
That means 192.168.1.<something>, same as your router and computer.

Sorry this is a small bit over my head, so if i go into the recording settings and change the subnetmask to 255.255.0.0 will this work then ill be able to change the ip address to 192.168.1.x (just making sure that x is outside the dchp range)

Maybe you can give me a step by step guide of what to do next and i can come back if that dosent work and try something else. Thanks for being patient

Yakuza

Go to the configuration page of your netopia, then click on Expert Mode, then Confiuration, Advanced, DHCP server.

Change the settings to ones similar to the ones attached.
(Note: the DHCP range is changed, as is the address of the configuration page (from 192.168.1.254 to 192.168.0.254).

http://img445.imageshack.us/img445/2524/dhcppl4.jpg

This will set the IP addresses that the DHCP server gives out in the same subnet as your recorder, and they should all be able to see each other fine - assuming the other machines on your network are using dhcp to get their addresses and the address wasn't set manually to 192.168.1.x

dvdfan

Yakuza wrote:

Go to the configuration page of your netopia, then click on Expert Mode, then Confiuration, Advanced, DHCP server.

Change the settings to ones similar to the ones attached.
(Note: the DHCP range is changed, as is the address of the configuration page (from 192.168.1.254 to 192.168.0.254).

http://img445.imageshack.us/img445/2524/dhcppl4.jpg

This will set the IP addresses that the DHCP server gives out in the same subnet as your recorder, and they should all be able to see each other fine - assuming the other machines on your network are using dhcp to get their addresses and the address wasn't set manually to 192.168.1.x

Perfect, exactly what i need. Ill give that a try and let you know how it goes

dvdfan

Just one more silly question,

should i not be changing the DCHP Strart and End ip address range to:

192.168.000.1 - 192.168.000.50

instead of 192.168.0.1 as you shown in the attached image considering the ip address of the recorder is 192.168.000.100

???

ressem

You've told us that you have 4 devices
Router 192.168.1.254 Subnet 255.255.255.0
1) Office Computer Downstairs 192.168.1.34 SN: 255.255.255.0
2) Point Of Sale Computer upstairs 192.168.1.? SN: 255.255.255.0
3) Recording System Office Downstairs 192.168.0.100 SN: 255.255.255.0


The point of sale computer is probably 192.168.1.33 or something. Just check, that it's not 100.
Just setting the ip of 3), the recording system to 192.168.1.100 SN: 255.255.255.0
will work.

There's just a possibility that if lots of computers were connected (it is a wireless router), that the IP might be reused by another device, preventing access.

It's best not to change the subnet. a 192.168 network with a class B (255.255.0.0) subnet can be disallowed by some devices configuration interfaces.

Yakuza

dvdfan wrote:

Just one more silly question,

should i not be changing the DCHP Strart and End ip address range to:

192.168.000.1 - 192.168.000.50

instead of 192.168.0.1 as you shown in the attached image considering the ip address of the recorder is 192.168.000.100

???

The end address *is* 192.168.0.50, the start address is 192.168.0.1.

There is no need to write the third octet as 000. "0" is just fine and the extra 0's just give more room for typos!

ressem

Don't change the DHCP from 192.168.1.x to 192.168.0.x unless you know that the point of sale device uses DHCP. Also it'll disconnect your pc from your router if you don't also change the ip of the router.

Just set the IP of the recording system.
Instructions to follow.

petes

Yakuza wrote:

The end address *is* 192.168.0.50, the start address is 192.168.0.1.

There is no need to write the third octet as 000. "0" is just fine and the extra 0's just give more room for typos!

I would say he is better off leaving it as a 192.168.1.* setup than a 192.168.0.* setup as he has POS and office computer on the former.

ressem

From manual
Stop the device if it's recording. Otherwise setting cannot be changed.

"1. Press the SET UP button } <SETTINGS> } <INITIAL SET
UP/INFORMATION> } Select “ETHERNET” in the
<COMMUNICATION PORT SETTINGS> screen and then
press the ENTER button.
• The <ETHERNET> screen appears.

2. Select the setting to be changed by pressing the JOG Down Arrow, Up arrow
buttons and then press the ENTER button.

"
First you "JOG" to the IP ADDRESS By pressing Jog Down Arrow
Press Enter
Press JOG Down Arrow till you highlight the 192.168.000.100
Press "Enter"
Press Up Arrow to set this number to 192.168.001.100
Press "enter"
And the ip should be set.

You might want to set the gateway address to 192.168.001.254 using the same method.

Yakuza

Cool - that should do it. When I saw the OP posting

p.s it wont allow me to change the ip address of the recorder via the setup menu

I assumed that his original network would have to change.

You should probably ignore what I posted earlier (or undo it!) given that you can change the IP of your recorder!

dvdfan

Cheers Lads,

It was a simple as changing the ip address on the recorder from 192.168.000.100 to 192.168.001.100 and that was it.

Thanks for all your help

petes

Glad you got it sorted.