Network/Internet 3-Router Issues/Questions

[calvyno]

Hello,

Because of the number of computers at various parts of my home, I have resorted to having a network setup with 3 routers. Currently my network is set up in the way shown in the image below, should be easy to understand:

Basically, I have the cable modem connected to a linksys router, then that linksys router is connected to a d-link router and another linksys router.

The inner layer routers. Since the inner routers do not need to really communicate with each other, I have them both set as 192.168.1.1. Of course, the outer linksys router should have a different IP, so I have it as 192.168.0.1.

Here are my problems...
Problem 1: Very often, the internet will cut out. It seems to be very unstable. For my ISP (COX High Speed Internet), it is generally reliable and fast. However it seems inside my home network, it will cut out a lot at random times for maybe period of 1 to 5 seconds at a time. This causes net surfing and uploading issues since it will cut off the transfer and end up corrupting a file in the middle of the transfer.

Problem 2: If there is a short power outage or a change in one of the router settings of any kind, I would have to reset all the routers. Not only that, I have to start them up in a specific order. I have to start the cable modem and the 2 inner routers up and wait for the cable modem to connect to the internet. THEN I can plug in/turn on the outer router. This is the only way that will allow my internet to work.

I've spent a lot of time and money trying to fix this problem, from switching routers, to getting a new cable modem, which seems to make it better. However, before I move on and spend more money into this I've decided to ask around on these forums.

I have read around and found that crossover network cables are required to connect between the routers. However, I think the cables I have connecting the routers right now are just straight through cables. Does routers connected together with straight through cables even work? Or can I assume because my internet somewhat works, that I'm using crossover cables already?

So my questions are, before I start making/buying some crossover cables:
1. Do I need a crossover cable between the cable modem and the outer router as well?
2. If I do not use crossover cables, would the network even work? Or would it just be unreliable like the problem I have now?
3. Do i need crossover cables between a router and a hub? (Currently I have a hub connected to one of the routers as well.)

Greatly appreciated!

 

[GhislainG]

Why do you have 2 routers on the same IP network? You can't have IP network 192.168.1.x twice, unless one of the two routers is powered off when the other one is active.

 

[calvyno]

Why do you have 2 routers on the same IP network? You can't have IP network 192.168.1.x twice, unless one of the two routers is powered off when the other one is active.

Well, I'm assuming, the outer router would assign each of the inner router a 192.168.0.xxx ip and the fact that they're both 192.168.1.xxx won't matter, because they're separated from each other. If a computer from one inner router wanted to reach a computer on the other inner router, they have to use a 192.168.0.xxx ip the outer router assigned.

But anyway, I can try changing the ip to 2 instead of 1, but I highly doubt that would fix the problem.

My questions were about crossover cables, not IP assignments. ^^

 

[GhislainG]

You shouldn't require crossover cables anywhere. Your addressing scheme should definitely cause problems.

Are the inner routers connected to the Linksys router via their Internet port or via a LAN port? If via the Internet port, then they should have a static IP address like 192.168.0.2 and 192.168.0.3. Then it doesn't matter if they have the same network range as long as hosts connected to the inner Linksys router don't need access to hosts on the D-link router. If they do, then use 192.168.1.0/24 and 192.168.2.0/24 and everything will work properly. You will also be able to reset a router without having to worry about the other routers.

 

[calvyno]

Ok, I changed the dlink address to 192.168.2.1.

Still had problems when restarting routers. I just made 3 crossover cables. Will try that now

 

[Guest]

I suspect you need DHCP enabled on the router attached to the internet and disabled on the other two routers.

 

[GhislainG]

Are the routers connected as follows?

Outer Linksys router: Internet port to modem (probably a dynamic IP address)
Inner Linksys router Internet port to Outer Linksys router LAN port (192.168.0.1 static IP address)
Inner D-Link router Internet port to Outer Linksys router LAN port (192.168.0.2 static IP address)

IP addresses 192.168.0.1, 192.168.0.2 and 192.168.0.3 are not in the DHCP range on the Outer Linksys router.

 

[GhislainG]

I suspect you need DHCP enabled on the router attached to the internet and disabled on the other two routers.

DHCP should be disabled only on the Internet port of the internal routers.

 

[calvyno]

I just changed all my router IPs to different ones.

Outer Linksys Router (192.168.1.1)
Inner D-link Router (192.168.2.1)
Inner Linksys Router (192.168.3.1)

Also switched the 3 network cables (between modem and routers) to crossover cables.

Do I really need to disable DHCP for the 2 inner routers now? I would assume there would be no problems if they were enabled since there's no IP interference.

 

[GhislainG]

I just changed all my router IPs to different ones.

Outer Linksys Router (192.168.1.1)
Inner D-link Router (192.168.2.1)
Inner Linksys Router (192.168.3.1)

Also switched the 3 network cables (between modem and routers) to crossover cables.

Do I really need to disable DHCP for the 2 inner routers now? I would assume there would be no problems if they were enabled since there's no IP interference.

The Internet IP address of the internal routers has to be static; otherwise you'll run into issues when resetting a router. You shouldn't let internal routers acquire an IP address from the outer router.

Note: The internal routers should have IP address 192.168.1.1 as their default gateway.

 

[sk1939]

The Internet IP address of the internal routers has to be static; otherwise you'll run into issues when resetting a router. You shouldn't let internal routers acquire an IP address from the outer router.

Note: The internal routers should have IP address 192.168.1.1 as their default gateway.

Agreed.

DHCP on the two inner routers should be fine, but the outer router should not have DHCP enabled. Your setup to me seems overly complicated...but then again the equipment needed to do it the way I would costs alot more lol. Also, as stated before, none of your routers should have overlapping address schemes as that causes problems.

 

[calvyno]

Ok, got it, so I should disable DHCP for the outer linksys router. From that point on it means I have to manually assign ip addresses in the settings for each inner router?

 

[sk1939]

Ok, got it, so I should disable DHCP for the outer linksys router. From that point on it means I have to manually assign ip addresses in the settings for each inner router?

You have to manually assign IP's for the outer interfaces, for the inner ones DHCP is fine as long as the addresses don't overlap.

 

[calvyno]

I guess i don't clearly understand how DHCP works. ^^

So...for the outside router (the one directly connected to the cable modem with IP 192.168.1.1):
- I should disable Local DHCP Server

For the inside routers (the 2 routers connected to the outside router with IPs 192.168.2.1 and 192.168.3.1):
- Enable local DHCP server

Then what? I thought disabling DHCP would require any computer or router connected to it to manually set their IP address for the outer router. In other words, I would have to go into the D-link router settings (192.168.2.1) and manually set its IP to 192.168.1.xxx. Then I would have to do the same for the other inner linksys router settings (192.168.3.1) and manually set its IP to a 192.168.1.xxx IP that is different from the one I just set for the dlink router?

Or is that completely wrong?

 

[GhislainG]

Why do you need to disable DHCP on the outer Linksys router? Is the outer router Internet Connection Type set to "Obtain an IP automatically"? You need to assign an IP address to the Internet interface of the innner routers. You can leave DHCP enabled on the outer router, but make sure that Start IP Address is higher than both IP addresses for the inner routers.

I have a similar setup, but mine is a bit more complex than yours with 4 routers.

 

[GhislainG]

Or is that completely wrong?

It is wrong.

 

[sk1939]

Why do you need to disable DHCP on the outer Linksys router? Is the outer router Internet Connection Type set to "Obtain an IP automatically"? You need to assign an IP address to the Internet interface of the innner routers. You can leave DHCP enabled on the outer router, but make sure that Start IP Address is higher than both IP addresses for the inner routers.

I have a similar setup, but mine is a bit more complex than yours with 4 routers.

If he still has to assign static addresses anyways, then why the f*** would he have to turn DHCP on to begin with, especially if no comptuers are connected to that router, that just adds complication, a headache and no real purpose.

If you do leave DHCP on, your address range will have to change to 192.168.1.4 -192.168.1.254, but you don't really have to leave DHCP on anyways...



Simple solution:

Outer Linksys Router (192.168.1.1) NO DHCP
Inner D-link Router Outside Interface: 192.168.1.2 Inside Interfaces (192.168.2.1) DHCP OK
Inner Linksys Router Outside Interface 192.168.1.3 Inside Interfaces (192.168.3.1) DHCP OK

 

[GhislainG]

The OP didn't say that no computers are connected to the outer router and DHCP doesn't add to the complexity. All he has to do is make sure that DHCP starts at an IP address higher than 192.168.1.3. I usually start DHCP at 100 or higher.

 

[sk1939]

The OP didn't say that no computers are connected to the outer router and DHCP doesn't add to the complexity. All he has to do is make sure that DHCP starts at an IP address higher than 192.168.1.3. I usually start DHCP at 100 or higher.

Although starting at that point just effectively halfed your useable DHCP address space, although I doubt that its a concern for you. While DHCP dosen't add to the complexity persay, it's something else to figure out and worry about, especially if it's not going to be used in the first place.

OP, do you have computers connected to that first router?

 

[calvyno]

Thanks sk1939. your reply is finally a straightforward answer on what I wanted to know.

However, GhislainG is right. I sometimes do have computers connected to the outside router. In which case, it would be safe to have the following settings with all DHCP enabled?
Outside Linksys Router - 192.168.1.1 - from .10 to .90
Inside Linksys Router - 192.168.1.2 - from .91 to .170
Inside Dlink Router - 192.168.1.3 - from .171 to .254

After this thread, I don't think I fully understand how DHCP works anymore. lol ><

As of now, my internet is working, although I'm still having some random slowdowns and 1-5 second disconnects. Don't think it's caused by the IP assignment issue, does it?

 

[sk1939]

Thanks sk1939. your reply is finally a straightforward answer on what I wanted to know.

However, GhislainG is right. I sometimes do have computers connected to the outside router. In which case, it would be safe to have the following settings with all DHCP enabled?
Outside Linksys Router - 192.168.1.1 - from .10 to .90
Inside Linksys Router - 192.168.1.2 - from .91 to .170
Inside Dlink Router - 192.168.1.3 - from .171 to .254

After this thread, I don't think I fully understand how DHCP works anymore. lol ><

As of now, my internet is working, although I'm still having some random slowdowns and 1-5 second disconnects. Don't think it's caused by the IP assignment issue, does it?

You could do that, but remember that DHCP is nonroutable, and what the router does is perform NAT, so basically it takes one IP address and allows alot of other IP addresses to connect to it. What are you using for ethernet cable, and what are the distances?

The only problem with your address schema is that while the IP's don't overlap, they are on the same network, which means if your trying to isolate the networks, you just failed at it.

EDIT: I just tried your configuration...yes it will work, and no it won't find the other networks due to the routers built in firewall. But that dosen't explain the slowdowns.

 

[calvyno]

That's a good point, sk1939.

My routers and modem are actually within 2 feet of each other, the network cables connecting between all 4 of these routers and modems are crossover cables.

In the end, I might just disable DHCP for the outer router like you mentioned earlier. This just means I have to manually set the IP in the PC settings for the PCs that are connected to that router right?

Actually, is this even the reason my internet is cutting a few seconds at a time?


Edit::a more clear example of my problem I'm having. When I submitted this reply, it loaded only the top part of the tom's hardware page, and I had to wait about 10-15 seconds before the rest of the page started loading. At the same time, i was refreshing my yahoo mail page, which also seemed to not load during the same time. I am assuming during this time my internet was cut off again and it was reestablishing the connection to the sites.

 

[sk1939]

That's a good point, sk1939.

My routers and modem are actually within 2 feet of each other, the network cables connecting between all 4 of these routers and modems are crossover cables.

In the end, I might just disable DHCP for the outer router like you mentioned earlier. This just means I have to manually set the IP in the PC settings for the PCs that are connected to that router right?

Actually, is this even the reason my internet is cutting a few seconds at a time?


Edit::a more clear example of my problem I'm having. When I submitted this reply, it loaded only the top part of the tom's hardware page, and I had to wait about 10-15 seconds before the rest of the page started loading. At the same time, i was refreshing my yahoo mail page, which also seemed to not load during the same time. I am assuming during this time my internet was cut off again and it was reestablishing the connection to the sites.

If you saw my edit, your config that you posted a few minutes ago should work fine. You do realize that from the modem to the router you shouldn't need a crossover cable? Alot of the more modern equipment besides does auto crossover to begin with.

Who is your ISP and what kind of connection are you using?

 

[calvyno]

I have Cox cable intenet.

I actually took that speed test just now. I've done a few, and every time I've took the test my internet didn't seem to have any problems, which is kinda odd, kinda like my internet knows when to make itself look good and when it doesn't have to care.

Although I think the packet loss for the pingtest is the problem I'm talking about. I ran the test a few times, and the packet loss jumps from 0% up to 3%.

Having a crossover cable between the cable modem and the router won't cause any problems though right? I mean, I'm on the internet now, obviously, posting on this forum after all. ^^

 

[sk1939]

I have Cox cable intenet.
http://www.speedtest.net/result/801947180.png
[url]http://www.pingtest.net/result/16059346.png[/URL]

I actually took that speed test just now. I've done a few, and every time I've took the test my internet didn't seem to have any problems, which is kinda odd, kinda like my internet knows when to make itself look good and when it doesn't have to care.

Although I think the packet loss for the pingtest is the problem I'm talking about. Sometimes when I take the test it is around 3%.

Having a crossover cable between the cable modem and the router won't cause any problems though right? I mean, I'm on the internet now, obviously, posting on this forum after all. ^^

I'll say it shouldn't unless it's homemade as that can cause problems. Your internet speeds seem kinda slow, but the thing to remember about a cable connection is that while you are allocated bandwidth of 15mbps or whatever, your neighboorhood only has a max of like for example 50mbps, so if someone is Bittorrenting, they've significantly lowered the bandwidth left. Cable and to a lesser extent, DSL are shared connections. I think your problem may either have to do with either your computers (alot of them?), hand terminated cables (cause similar problems), poor cable line quality (also causes similar problems), or dying equipment (routers and nics cause strange problems when they're on their way out).