# Splitting IPs



## Tau (Oct 14, 2008)

Alright for the past week or so my internet speed has dropped down to ~1/2 of the normal bandwidth.  I just finished a bunch of testing and have narrowed it down to my hub being the choke point (weird as it was fine a week or two ago.)

Here is a basic illustration of my current network setup, also know that my ISP is providing me iwth two IPs and i am using the hub to split those IPs, one to a machine, the other to a router.

[Cable Modem]---[HUB]---[ROUTER]---[SWITCH]---[PC1]
                               ---[COMPUTER]              ---[PC2]
                                                                  ---[ACCESS POINT]

The hub is splitting the IPs, the computer gets one, and the router gets the other one.  

Now when i plug directly into the cable modem i get full speed, everything through the router gets ~1/2 speed, and the other computer thats hooked into the hub gets 1/2 speed as well.  So this points to the hub being the culprit.

Is there any other way that i can split IPs other than a hub?  As i also notice the collision light going off constantly on the hub.


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## panchoman (Oct 14, 2008)

your router uses internal ip's to seperate all of the devices on the network, is that what you mean by splitting ips?


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## Tau (Oct 14, 2008)

panchoman said:


> your router uses internal ip's to seperate all of the devices on the network, is that what you mean by splitting ips?



No.

I know that the DHCP server inside the router is assigning ips to all the computer connected to it.

My ISP provides me with two IPs from my cable modem (one ethernet cable out, two ips over it).  I need to know if there is any other way other than a hub to seperate these ips onto their own run of ethernet.

(i hope that makes sence)

I have a couple idea i will be testing out tommorow, will report back.


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## Deleted member 3 (Oct 14, 2008)

Hubs don't work on IP level. You can't "seperate" IP's. From what I understand your cable modem acts as a bridge, and your ISP allows two clients. Your router being one client.
Everything connected to your router will connect via the IP the router uses, the other is left out of the picture.


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## speedkills (Oct 14, 2008)

Most routers can be configured to handle mutliple host IP addresses. However, I am a bit perplexed by your network configuration (unless additional hardware connectivity has been omitted). In general terms, hubs simply repeat incoming signals to all connected ports (which raises traffic and possible congestion), where switches use MAC tables to learn connected devices and allocate bandwidth and packets to each segment, and then routers are (for the most part) advanced switches with capabilities to fully route traffic directly to clients and provide other network management capabilities (such as DHCP, port forwarding, firewalls, etc.).

Based on your layout above, I don't see why you would need a switch between your PC1 and the router. In addition, most routers should be more than capable of handling your two PCs and an access point. Depending on your router model, it might also have the capabilities for routing your two different IP addresses (most do), which would negate the need for a managed hub.


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## Mussels (Oct 14, 2008)

If your ISP is giving you two IP's, there is only two solutions.

1. Disable DHCP in your router (bridge mode) and connect no more than two PC's. This gives them direct net access.

2. Enable DHCP, giving you local IP addresses and not internet ones. This will require port forwarding to host games/servers (which is common for all routers)

When you say hub, you arent being informative. Is it a hub or a switched hub. Is it full/half duplex? is it 10Mb, 100Mb, or gigabit? how many devices are on it? What model router do you have?

Your best network setup is
Modem->Router (with DHCP)->Switched hub-> PC's


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## Tau (Oct 14, 2008)

speedkills said:


> Most routers can be configured to handle mutliple host IP addresses. However, I am a bit perplexed by your network configuration (unless additional hardware connectivity has been omitted). In general terms, hubs simply repeat incoming signals to all connected ports (which raises traffic and possible congestion), where switches use MAC tables to learn connected devices and allocate bandwidth and packets to each segment, and then routers are (for the most part) advanced switches with capabilities to fully route traffic directly to clients and provide other network management capabilities (such as DHCP, port forwarding, firewalls, etc.).
> 
> Based on your layout above, I don't see why you would need a switch between your PC1 and the router. In addition, most routers should be more than capable of handling your two PCs and an access point. Depending on your router model, it might also have the capabilities for routing your two different IP addresses (most do), which would negate the need for a managed hub.




There are actually 7 machines on that switch, along with a WAP with 4 wifi clients.

I had tried this same configuration with a switch inplace of the hub before and couldent get it to work, though that was ages ago and i probobly got something wrong.  I will be trying the setup with a switch inplace of the hub, and connect one output from the switch to a machine, and the other output to a router.  As far as i can tell this should work, and the machine should get its own IP, and the router get my second IP. 

The other question on this setup is, would the machine be able to communicate through the switch with the other network?  Or would everything router forward be seperated?

Thanks.


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## Mussels (Oct 14, 2008)

everything the router forwards is on a different IP subnet, and therefore cannot communicate with the direct IP system.

I seriously suggest you to just buy a good all in one router (modem, router, wireless AP) and then connect that up to a switch (8+ ports by the sound of your network). Its simple, its effective, and it will fix your problems.


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## Yin (Oct 14, 2008)

If you have a cable connection and the ISP only provides you 2 IP address. One has to go to the cable modem obviously. Leaving you 1 valid IP address, Meaning in your case you need to have the Cable mdm > Router.


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## Steevo (Oct 14, 2008)

The easiest way to bridge two connections is a cheap WAN side box and aggregate the connections(assuming you have two modems). A older PC with two NIC's and Linux will do the trick.


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## Tau (Oct 14, 2008)

Yin said:


> If you have a cable connection and the ISP only provides you 2 IP address. One has to go to the cable modem obviously. Leaving you 1 valid IP address, Meaning in your case you need to have the Cable mdm > Router.



The cable modem does not get an IP.



Steevo said:


> The easiest way to bridge two connections is a cheap WAN side box and aggregate the connections(assuming you have two modems). A older PC with two NIC's and Linux will do the trick.




I must be explaining it wrong, as this is all the wrong ideas.

Thanks for the ideas guys, i will figure it out here on my own.


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## Mussels (Oct 15, 2008)

Tau said:


> The cable modem does not get an IP.



well it should be. its needed.


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## Yin (Oct 15, 2008)

Tau said:


> The cable modem does not get an IP.
> 
> 
> 
> ...



i don't mean to be rude or anything but

I am 100000% sure it does or it should.


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## AphexDreamer (Oct 15, 2008)

Wait instead of using a HUB why don't you replace it with an other Switch?


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## ktr (Oct 23, 2008)

Do you have a Dynamic or Static IP from your ISP. I don't think an ISP will give you multiple dynamic IP address. 

Also remove the HUB. Nobody uses hubs. Hubs are multi-port repeaters, so they just podcast the same frame to all ports. Because of this, a frame that should only go to one computer goes to all computers. When the destination MAC of the frame matches the computer on the network, the frame will be accepted by that computer, and the rest of the computers will reject it.


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