# DHCP issues with new switch...



## passion_unlimitedd (Apr 29, 2009)

Hi guys.

One of my friends runs a cyber cafe. His network looks somewhat like this:



```
ADSL modem ----- Machine A ----- 10 Mbps Hub ----- Machines B through F
```
Machine A runs Windows XP, and handles the PPPoE dial-up part of the ADSL connection.
Machines B through F run Windows 2000/XP.

We wanted to add 6 more machines to the network. We grabbed ourselves a switch, and this is how our network now looks like:




```
ADSL modem ----- Machine A ----- 10 Mbps Hub ----- Machines B through F
[COLOR="White"][COLOR="Silver"]ADSL modem ----- Machine A[/COLOR][/COLOR] ----- 10/100 Mbps Switch ----- Machines G through K
```



Machines G through K run Windows XP.

The problem is that machines G through K consistently exhibit a "Limited or no connectivity" error. Hard-setting the IP address helps sometimes.

What do you guys think? Where did we go wrong?


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## FilledVoid (Apr 29, 2009)

Although I'm not quite sure of the problem Id rather just connect the Switch to the hub or remove the hub and use the switch if it has that many ports. I'm guessing that somehow that somehow one group is getting IPs assigned from one computer while the other is getting it assigned from the Switch hence using overlapping ranges. I might be wrong so you might want to post your configurations to confirm  .


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## prateek007391 (Apr 29, 2009)

In my cyber cafe I have the layout of the connections as shown in Attached Image

If you have less than 10 Systems u even don't need Hub they make network slow and clumsy

This kind of network layout worked for me the most it is called "Star Networking"

And let me know how many port does your Switch has and how many Systems are there in Cyber cafe


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## passion_unlimitedd (Apr 29, 2009)

FilledVoid said:


> Although I'm not quite sure of the problem Id rather just connect the Switch to the hub or remove the hub and use the switch if it has that many ports. I'm guessing that somehow that somehow one group is getting IPs assigned from one computer while the other is getting it assigned from the Switch hence using overlapping ranges. I might be wrong so you might want to post your configurations to confirm  .




2 Lan cards attached in machine A
Hub is getting connection from 1st lan card and that network working fine
switch is getting connection from 2nd lan card and not working.

I have tried giving connection from Hub to switch ( with Straight / Cross cables) but no results.

Both the lan cards, cables (straight/cross), switch are checked and are ok.


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## passion_unlimitedd (Apr 29, 2009)

prateek007391 said:


> In my cyber cafe I have the following layout of the connection
> 
> ADSL Modem -------- Switch ----- 10 Mbps Hub ---Computer
> |
> ...




I have a total of 12 computers.

6 computers are already running with the hub (8 port) from last 7 years without any problem. (Star Topology)

Now i have added another 6 computers with the switch (8 port) which is not getting the connection.


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## prateek007391 (Apr 29, 2009)

passion_unlimitedd said:


> I have a total of 12 computers.
> 
> 6 computers are already running with the hub (8 port) from last 7 years without any problem. (Star Networking)
> 
> Now i have added another 6 computers with the switch (8 port) which is not getting the connection.


 
How many ports are there in ur Network Switch and Hub


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## yippee (Apr 29, 2009)

what is the hub and switches ip?


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## passion_unlimitedd (Apr 29, 2009)

prateek007391 said:


> How many ports are there in ur Network Switch and Hub



Already written. 8 each.


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## FilledVoid (Apr 29, 2009)

Basic checks. 
1. Turn off the HUB 
2. Does all machines connected to the switch work fine  when the HUB and its respective group of computers is not functioning?
3. You might want to check also if the switch is assigning IP addresses to that set of computers while the other network is being assigned IP addresses from the machine / router/ hub whatever. In other words check the settings for each IP address on your machine. Why not just configure it with Static IP in the first place ?


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## yippee (Apr 29, 2009)

FilledVoid said:


> Why not just configure it with Static IP in the first place ?


true it seems like ip/routing conflict to me...


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## passion_unlimitedd (Apr 29, 2009)

FilledVoid said:


> Basic checks.
> 1. Turn off the HUB
> 2. Does all machines connected to the switch work fine  when the HUB and its respective group of computers is not functioning?
> 3. You might want to check also if the switch is assigning IP addresses to that set of computers while the other network is being assigned IP addresses from the machine / router/ hub whatever. In other words check the settings for each IP address on your machine. Why not just configure it with Static IP in the first place ?




I will try step 1 & 2.

I already tried step 3 and the switch is not assigning any ip to the pcs.


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## passion_unlimitedd (Apr 30, 2009)

*No more suggestions ....*


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## prateek007391 (Apr 30, 2009)

_*Then *_
_*close *_
_*down *_
_*this *_
_*thread*_


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## FilledVoid (Apr 30, 2009)

Why is his problem solved?


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## choudang (May 1, 2009)

Guys ..... first of all .. i am not able to understand the logic to use a hub and a switch parallelly. User is having 12 PCs (6+6) and AFAIK, we can use a single switch to get connected. Long time back, i had a same requirement to go live with 16 PCs and i was successful straightway. 

I had one PC with two lan card A and B, LAN A was connected to ADLS and LAN B was connected to the switch. I have made a workgroup called "MEGA INFO" and made the ADSL connection shared. I was using simple 192.168.1.10 - 24 for my switch connected pcs, and LAN B was having 192.168.1.5. 

for above prob... i would suggest to create a workgroup and try to join the switch connected pcs into that. again, if you turn off the HUB, switch won't get connected. you can try another thing here

ADSL ---- PC --- HUB 1 ------- HUB 2
ADSL ---- PC --- HUB 1 ------- SWITCH

AFAIK, we need to register the new machines into the existing workgroup / domain to use the DHCP, correct me if i wrong


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## satyamy (May 1, 2009)

My Suggestion
if you want to get rid of this prob without too much headache than

Sell your old switch using Bazaar Section of Digit forum

and buy a New 16 or 24port Switch

link 
*cgi.ebay.in/iBall-Baton-16-Port-10...ms=66:1|65:1|39:1|240:1318|301:1|293:1|294:25

or 

*cgi.ebay.in/iBall-Baton-24-Port-10...ms=66:1|65:1|39:1|240:1318|301:1|293:1|294:25

and simply connect

Eg : 
*img118.imageshack.us/img118/6672/16portswitch.th.jpg*img118.imageshack.us/my.php?image=16portswitch.jpg


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## satyamy (May 1, 2009)

-----------------------------------------------------------------------------------

A Friend of My Who has 2 Offices one in 3rd floor and other in 1st floor shares a Same ADSL Connection (MTNL Triband) and all of his PC's are in same network (sharing files) has a system like this

*img118.imageshack.us/img118/6897/adslconnection2switch.th.jpg


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## NucleusKore (May 1, 2009)

Do this

*img160.imageshack.us/img160/853/networkb.th.jpg


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## prateek007391 (May 1, 2009)

hey explain me more deeply

hub to hub the to switch

do we need different coding for patch cables


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## choudang (May 1, 2009)

^^ it would be cross cable .. 

@NucleusKore: i hope OP has posted the thread after trying the same, he used HUB instead of switch as per your method i suppose.

@satyamy: yes .. this is the most simple example if you need to establish connectivity, pl note that all 7 machines using static IP and in the same WG.

@*OP*: hope this will help..
*img13.imageshack.us/img13/9995/lanx.th.jpg


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## NucleusKore (May 1, 2009)

If you have a 8 port switch
one port to main broadband PC
one port to hub
six ports to cyber PCs


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## choudang (May 1, 2009)

^^ i think OP has faced after doing that ....


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## NucleusKore (May 1, 2009)

Is it? Let's see what he says


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## FilledVoid (May 1, 2009)

As per OP 
1. He has a 8 port switch and a 8 port hub. 
2. Hes having connectivity issues when he uses DHCP

As per my suggestions
1. Change the IP addressing to Static (Its not likes its going to make a huge difference)
2. As said above make sure you are using the right IP addresses, Workgroup Name, Subnet Mask, gateway etc. 
3. Specify explicitly where to get the DHCP address from if you insist on using DHCP. (I'm not using WIndows but I believe there's an option for this. 



> Guys ..... first of all .. i am not able to understand the logic to use a hub and a switch parallelly. User is having 12 PCs (6+6) and AFAIK, we can use a single switch to get connected. Long time back, i had a same requirement to go live with 16 PCs and i was successful straightway.


If you have 12 machines and just an 8 port hub or switch then what exactly do you intend on doing ? You could of course return the switch and just get another one with more ports if you want.


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## passion_unlimitedd (May 2, 2009)

Thank you guys for all your suggestions.

I did it myself atlast.

1. I was using the 8 port Hub since last 7 years and working fine, so no point of replacing that with expensive 16 or 20 port switch. So I got a new 8 port switch (since Hub is not available these days here or I'd have bought a hub) to connect other PCs.

2. Switch was getting connection from the Hub. All the Pcs use DHCP. The PCs getting connection from Switch was not getting IP.

3. So the main problem was not getting the IP. The Hub was giving 10 Mbps and Switch 100 Mbps and the problem was somewhere there (though it should have worked)

4. My Hub was 10 base t and switch was 100.

5. That was the main problem and though the NICs were configured as auto it was not getting the desired IP.

6. So what I did is changed the NIC from Auto to 10 Full Duplex Mode and it solved my problem.


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## passion_unlimitedd (May 2, 2009)

Thank you guys for all your suggestions.

I did it myself atlast.

1. I was using the 8 port Hub since last 7 years and working fine, so no point of replacing that with expensive 16 or 20 port switch. So I got a new 8 port switch (since Hub is not available these days here or I'd have bought a hub) to connect other PCs.

2. Switch was getting connection from the Hub. All the Pcs use DHCP. The PCs getting connection from Switch was not getting IP.

3. So the main problem was not getting the IP. The Hub was giving 10 Mbps and Switch 100 Mbps and the problem was somewhere there (though it should have worked)

4. My Hub was 10 base t and switch was 100.

5. That was the main problem and though the NICs were configured as auto it was not getting the desired IP.

6. So what I did is changed the NIC from Auto to 10 Full Duplex Mode and it solved my problem.


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## passion_unlimitedd (May 2, 2009)

Thank you guys for all your suggestions.

I did it myself atlast.

1. I was using the 8 port Hub since last 7 years and working fine, so no point of replacing that with expensive 16 or 20 port switch. So I got a new 8 port switch (since Hub is not available these days here or I'd have bought a hub) to connect other PCs.

2. Switch was getting connection from the Hub. All the Pcs use DHCP. The PCs getting connection from Switch was not getting IP.

3. So the main problem was not getting the IP. The Hub was giving 10 Mbps and Switch 100 Mbps and the problem was somewhere there (though it should have worked)

4. My Hub was 10 base t and switch was 100.

5. That was the main problem and though the NICs were configured as auto it was not getting the desired IP.

6. So what I did is changed the NIC from Auto to 10 Full Duplex Mode and it solved my problem.


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## NucleusKore (May 2, 2009)

Ok Ok I get the point 

*s269.photobucket.com/albums/jj44/visio159/Unismilies/38large.png


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## FilledVoid (May 2, 2009)

> 2. Switch was getting connection from the Hub. All the Pcs use DHCP. The PCs getting connection from Switch was not getting IP.





> 3. Specify explicitly where to get the DHCP address from if you insist on using DHCP. (I'm not using Windows but I believe there's an option for this.





> 3. You might want to check also if the switch is assigning IP addresses to that set of computers while the other network is being assigned IP addresses from the machine / router/ hub whatever. In other words check the settings for each IP address on your machine. Why not just configure it with Static IP in the first place ?





> I'm guessing that somehow that somehow one group is getting IPs assigned from one computer while the other is getting it assigned from the Switch hence using overlapping ranges.


Had you taken the time to confirm that the IPs were being assigned correctly this problem would have been solved ages ago.


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## yippee (May 2, 2009)

@passion_unlimitedd i told you before to check the ip's


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## satyamy (May 2, 2009)

passion_unlimitedd said:


> Thank you guys for all your suggestions.
> 
> I did it myself atlast
> ...................
> I did is changed the NIC from Auto to 10 Full Duplex Mode and it solved my problem.


Finally Prob is solved 
Congrats
Keep it Up


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