Help with switch connectivity

adocholiday

Hi all,

I am trying to use a switch to give internet connectivity to 5 computers from one network point. I'm using a switch, this one specifically: http://www.tp-link.com/en/products/details/?model=TL-SF1008D

I'm using standard Ethernet cable to connect the switch directly to a network point on the wall. If I connect a cable from here to a PC it works fine. I don't need a crossover cable as per the manufracturer. Using the switch, one computer picks up a net connection. If I use ipconfig I get different IP's and gateways from the other computers than the one with the net connection. What am I missing here? Any help would be really appreciated

FSL

As long as all the PC's are set to automatically get their IP address then they should all work. All the PC's should have a different IP address but in the same range. The default gateway should be the same and equal to the IP address of the router.

Make sure the PC's which have not got connectivity do not have a static IP addresses and gateway address.

Young Farmer

I hears j doyle is the men for the job??

yoyo

Young Farmer wrote: »

I hears j doyle is the men for the job??

What? :o

Young Farmer

I think a lad j doyle knows how ta fix dat problem. cud be wrong doh

adocholiday

I'm not using a router I'm just using a switch. You connect an ethernet cable from the network point to one of its ports and all of the computers to the switch. It's not the same as a router.

Young Farmer

did you try and disconnect the router first and try to install it again for the 5 computers. I did this with mine and it worked

IT-Guy

adocholiday wrote: »

I'm not using a router I'm just using a switch. You connect an ethernet cable from the network point to one of its ports and all of the computers to the switch. It's not the same as a router.

Could be your problem right there, if you're not using a router what dhcp server are you using? What is the point on the wall connected to, a cable internet service? Who is your ISP?

Young Farmer

what I dont understand? Could you talk in farmer language no??????

adocholiday

Bear with me on this! I'm working in an institution that has an internal network. Every network point is connected to this network. If I plug in a PC to the network point using an ethernet cable, the PC has internet connection. The PC's do not have a network client or anything like Novell. They are stand alone machines that just get internet connection from the network.

I assumed that if the wall connection provides an internet connection to a PC, surely it would do the same with the switch? I've never used a switch before so I'm not sure where the problem is.

If I was to put a router in the loop somewhere would that fix it?

Young Farmer

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ye i no wa ya mean

yoyo

Young Farmer wrote: »

m
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ye i no wa ya mean

10 day ban for trolling

Nick

Scartbeg

adocholiday wrote: »

Bear with me on this! I'm working in an institution that has an internal network. Every network point is connected to this network. If I plug in a PC to the network point using an ethernet cable, the PC has internet connection. The PC's do not have a network client or anything like Novell. They are stand alone machines that just get internet connection from the network.

I assumed that if the wall connection provides an internet connection to a PC, surely it would do the same with the switch? I've never used a switch before so I'm not sure where the problem is.

If I was to put a router in the loop somewhere would that fix it?

That switch should be pretty foolproof -all ports can act as an uplink, autodetect of cable type.

So you have one PC connected OK though the switch?
Have the other PC's ever been active on the network - it could be that DHCP server has no more addresses available, or MAC address security is being used to stop unregistered devices connecting to the network.

What address ranges are the non-working PC's showing?
If its 169.x.x.x then they are unable to get an IP from the network and are using ad-hoc IP's. That could be cabling (unlikely on all 5 PC's) or network security as above, in which case you need to talk to the admin.

Your working PC probably has an address starting 10.x.x.x, 172.16.x.x or 192.168.x.x right?

It would help if you could post the IP's and gateways of all the PC's (safe to do so if they are all private IP adresses in the ranges above)

FSL

adocholiday wrote: »

Bear with me on this! I'm working in an institution that has an internal network. Every network point is connected to this network. If I plug in a PC to the network point using an ethernet cable, the PC has internet connection. The PC's do not have a network client or anything like Novell. They are stand alone machines that just get internet connection from the network.

I assumed that if the wall connection provides an internet connection to a PC, surely it would do the same with the switch? I've never used a switch before so I'm not sure where the problem is.

If I was to put a router in the loop somewhere would that fix it?

You already have a router in the network otherwise it would not work. The Ethernet socket you are referring to will be connected either directly or via another switch to the router. Plugging the new switch into the point gives you additional connections. If one PC attached to the switch works then so should any other as long as it is set to automatically get an IP address.

Scartbeg

Or, the 4 PCs which are not working may have been set up with predefined IPs/gateways in their previous life. i.e. not set to automatically obtain an IP address from the network DHCP server.

Whatever OS you are using, dig into the network settings and look for DHCP - set it to automatic if necessary.

adocholiday

I've checked the network settings on all of the computers. They're all set to auto DHCP no specific settings on any of them. I set them up myself and didn't change any network settings.

All of the pc's connect to the internet from the network point individually. The problem is definitely with the switch. Will try new switch tomorrow to remove the possibility of that being the problem.

adocholiday

Ok have tried new switch having same problem. Here are the ipconfigs of the 5 computers:

All 4 with no internet - IP: 169.254.x.x, SNet Mask: 255.255.0.0, gateway 0.0.0.0

Comp with internet: 137.43.x.x (leaving blank for security reasons), SNet Mask: 255.255.254.0
Gway: 137.43.x.1

On comps with no access, network diagnostic says 'LAN has no IP configuration'

Do switches have a MAC address of their own? All computers here have to register their MAC address with the network before they can access the net. All of these computers are registered but could this be a problem?

Nothingbetter2d

adocholiday wrote: »

Hi all,

I am trying to use a switch to give internet connectivity to 5 computers from one network point. I'm using a switch, this one specifically: http://www.tp-link.com/en/products/details/?model=TL-SF1008D

I'm using standard Ethernet cable to connect the switch directly to a network point on the wall. If I connect a cable from here to a PC it works fine. I don't need a crossover cable as per the manufracturer. Using the switch, one computer picks up a net connection. If I use ipconfig I get different IP's and gateways from the other computers than the one with the net connection. What am I missing here? Any help would be really appreciated

is the pc connected to the net using a 3g dongle? And has internet connection sharing enabled? to get the ip address goto start > accessories > run : cmd then ipconfig /all

if yes you will need to note the pc's ip address (it should be something like 192.168.1.1) and then go to all the other pcs and set a static ip address similar to the pc that is connected (ie: 192.168.1.2 - 5) and set the default gateway to what ever the connected pc's ip address is.

example:

Pc 1 with 3g dongle plugged in and set to internet connection sharing enabled = 192.168.1.1 dont set this pc to static ip as the dongle gives it the ip address
Pc 2 set static ip 192.168.1.2 and default gateway to 192.168.1.1 - primary dns 8.8.8.8 secondard dns 8.8.4.4
Pc 3 set static ip 192.168.1.3 and default gateway to 192.168.1.1 - primary dns 8.8.8.8 secondard dns 8.8.4.4
Pc 4 set static ip 192.168.1.4 and default gateway to 192.168.1.1 - primary dns 8.8.8.8 secondard dns 8.8.4.4
Pc 5 set static ip 192.168.1.5 and default gateway to 192.168.1.1 - primary dns 8.8.8.8 secondard dns 8.8.4.4

while i wait for my phoneline to be repaired by eircom i am using a meteor 3g dongle and thats how i have my 5 computers setup.

fionny

adocholiday wrote: »

Ok have tried new switch having same problem. Here are the ipconfigs of the 5 computers:

All 4 with no internet - IP: 169.254.x.x, SNet Mask: 255.255.0.0, gateway 0.0.0.0

Comp with internet: 137.43.x.x (leaving blank for security reasons), SNet Mask: 255.255.254.0
Gway: 137.43.x.1

On comps with no access, network diagnostic says 'LAN has no IP configuration'

Do switches have a MAC address of their own? All computers here have to register their MAC address with the network before they can access the net. All of these computers are registered but could this be a problem?

Internal IP's pose no security risk, and external IP's are easy to get anyway so dont sweat it.

If the comp with the internet connection has an internal ip of 137.43.0.1 and the mask if 255.255.254.0 then all the other computers should have the same.

So Switch Connection Comp 1 should be something like 137.43.0.2 and the EXACT same subnetmask and gateway ip.

Try assigning the ip's on the computer instead and bypass dhcp, just make sure you dont use conflicting ip's so try use a higher end of the ip range or something.

Scartbeg

fionny wrote: »

Internal IP's pose no security risk, and external IP's are easy to get anyway so dont sweat it.

If the comp with the internet connection has an internal ip of 137.43.0.1 and the mask if 255.255.254.0 then all the other computers should have the same.

So Switch Connection Comp 1 should be something like 137.43.0.2 and the EXACT same subnetmask and gateway ip.

Try assigning the ip's on the computer instead and bypass dhcp, just make sure you dont use conflicting ip's so try use a higher end of the ip range or something.

You *could* try setting static IP's high in the address range, however I would discourage this practice as you may cause potential conflicts if the DHCP server gives out the same address to another user. You may be blocked from having more than one MAC address simultaneously per network port.

Given the organisation you are in (which I can tell from the public IP info 137.43.x.x that you quote), I suspect that the main switches are set up to allow one mac address per port by default. Although it's a large subnet (2046 hosts possible) you would easily use that address space up in an organisation that large. And these are public IP's which should be used sparingly.

You really should have a word with the network admins, who should be able to facilitate what you are doing by reconfiguring the main switch.

adocholiday

Scartbeg wrote: »

fionny wrote: »

Internal IP's pose no security risk, and external IP's are easy to get anyway so dont sweat it.

If the comp with the internet connection has an internal ip of 137.43.0.1 and the mask if 255.255.254.0 then all the other computers should have the same.

So Switch Connection Comp 1 should be something like 137.43.0.2 and the EXACT same subnetmask and gateway ip.

Try assigning the ip's on the computer instead and bypass dhcp, just make sure you dont use conflicting ip's so try use a higher end of the ip range or something.

You *could* try setting static IP's high in the address range, however I would discourage this practice as you may cause potential conflicts if the DHCP server gives out the same address to another user. You may be blocked from having more than one MAC address simultaneously per network port.

Given the organisation you are in (which I can tell from the public IP info 137.43.x.x that you quote), I suspect that the main switches are set up to allow one mac address per port by default. Although it's a large subnet (2046 hosts possible) you would easily use that address space up in an organisation that large. And these are public IP's which should be used sparingly.

You really should have a word with the network admins, who should be able to facilitate what you are doing by reconfiguring the main switch.

Bang on Scartbeg that was it. Happy days