Install router, internet keeps going down

[drhowarddrfine]

I have two computers at one location with dsl.  Only one of the computers was online.  I didn't know this until a few days ago but, every couple of days, the 'net goes down and they had to restart the computer (not the modem) to get back online.  I had bought a router so the second computer could get online also.  After bringing everything up, the internet now goes down twice a day and the only way to bring it up is to restart the modem and router, and I think the computers, too.

At the same time, I had another location with the same setup that never had any internet down problems.  I installed the same router the same way and now it, too, goes down twice a day. 

I would blame the router (d-link ebr-2310) except for the fact that the one location had always had the problem going down but I also have a problem wanting to blame the ISP or the modem.  Both locations are within one city block of each other.

Any ideas from anyone?

[Mark Jones]

I have two computers at one location with dsl.  Only one of the computers was online.  I didn't know this until a few days ago but, every couple of days, the 'net goes down and they had to restart the computer (not the modem) to get back online.

Sounds like a TCP/IP DHCP problem. Check the PC's ability to renew an IP address. In XP go into your control panel, Network Connections, right-click on your connection and choose Repair. If the 'net stops after this, your problem is in there. (In Win 9x goto Run and type in Winipcfg then do Release and Renew.)

I had bought a router so the second computer could get online also.  After bringing everything up, the internet now goes down twice a day and the only way to bring it up is to restart the modem and router, and I think the computers, too. At the same time, I had another location with the same setup that never had any internet down problems.  I installed the same router the same way and now it, too, goes down twice a day.

Some ISP's do not allow the modem to connect to a router. I forget what settings are involved but try going into the router setup (I think you can get there by opening your web browser to http://192.168.0.1 ). If all else fails...

For customers within the United States:
Phone Support:
(877) 453-5465
24 hours a day, seven days a week.
Internet Support:
http://support.dlink.com
support@dlink.com

[drhowarddrfine]

I thought I would simplify things but, the truth is, the setup includes a POS computer with a credit card machine.  The computer is used only once or twice a week.  The credit card terminal is always on but you might not get a transaction every hour of the day, though we get quite a few.  The 'net seems to go down every four hours.  A dlink tech emailed me to check the Lease Time Option on the router and set it to a higher value.  I got the impression 'four hours' rang a bell with him.  That setting is under DHCP Server settings so I guess that's the area you are speaking of, too.

I'm wondering if the reason I'm having this problem is due to the fact that the credit card machine only has occasional bursts of short data and that makes something shut down, such as this Lease Time.

[Mark Jones]

Naah, the data traffic is truly irrelevant. The connection is being dropped because of basically, a protocol discrepancy. The modem probably "sees" the router's network as a 169.x.x.x (a so called Private Network) and is dropping the connection as a result. The ISP probablly passed the modem a flash-update (without your knowledge) to force it to not connect to any Private Networks, in an attempt to keep you from running more than one PC with the modem. Comcast has been known to do this, among others.

IIRC, the trick is to make the router present the modem with a non-private-network IP address. In other words, make the router "invisible" by making it seem like one computer to the modem -- then the problem should cease. While IP leases are typically 4h, 8h, or a day or two, IP addresses assigned by DHCP don't necessarily change every time they are renewed. That is, the IP assigned to your router might remain the same for months or more - the renew process is simply a function the DHCP server does to manage the IP address pool assigned by your ISP.

Just the very nature of the problem - works for awhile then stops - is indicative of a lease issue. Check the router's manual for a section on this, there must be something.

Also note there is a specific way you should "reboot" a network like this when troubleshooting:
1. XP pc's will reconnect automatically but 9x machines should be turned off.
2. Power off the router.
3. Power off the modem.
5. Wait 65 seconds. No skimping! It takes time for the electronics inside to drain completely.
6. Turn on modem. Wait for all lights to calm down (up to 2 minutes or so)
7. Turn on router. Wait again, usually a minute or less.
8. Power on any 9x PC's.

Happy hunting. :bg

[drhowarddrfine]

I'm using SBC and I'd be shocked if they didn't allow routers.  That's the first I've ever heard of that but, then again, I dumped them for cable.  Dlink told me how to set the lease time but I haven't had a chance to look at it yet.  Just tired today.

[MichaelW]

SBC has allowed routers for at least the last 3-4 years. I have used Linksys routers in combination with SBC ADSL on several networks, and the only significant problems have been with the SBC software (and the obvious solution has always worked). The 2wire modem that came with my current service (installed 8-05) includes a router.

[drhowarddrfine]

If I increase the lease time, isn't that just going to push the same problem further out?  iow, since the 'net went down every four hours and I change it to 8 hours or more, won't the net just go down every 8hours or more?  I don't understand why I don't have the same problem with my router at home.

[MichaelW]

There might be some useful information here:

http://forum1.netgear.com/support/viewtopic.php?t=7084

I have not tried to determine how long the SBC lease is or how frequently the IP address changes because I have no problems even with my system routinely running several weeks between restarts.

[PBrennick]

It is because your router is using Dynamic IP instead of a Static IP so every time your ISP resets your IP, you go down.  When you reboot, the Router obtains the new IP from the ISP during the Hanshake and you go back up.  One of your ISPs gave you a Static IP and the othe a Dynamic IP.  Contact your ISP and ask for a Static IP address.  If they both are already Static, then you have a Router configuration problem and you should log into the Routers and switch from Dynamic to Static IP.  You will probably be charged for the Static IP if you are not already as the source is becoming  limitted.

Paul

[drhowarddrfine]

Gotta tell ya', I'm immensely impressed with D-Links tech support.  I was hesitant to call the 800 number but I got through right away and to a guy who really knew his stuff! :U

Paul, I don't know if this is exactly what you were talking about but he agreed that the router is set for dynamic IP, which is OK but resets itself when the Time Lease expires and could drop that address giving the devices nowhere to go for internet service.  He had me switch to PPPoE and had me change the MTU to 1400 from 1492. 

He seemed very confident this was the whole solution but, unfortunately, I can't test this till tonight or tomorrow.  I see a lot of talk about PPPoE at DSLReports and I was always under the impression this wasn't used anymore so I am confused about what it is and where it all fits in but, for some reason, I just struggle with networking.  Maybe because it becomes a set and forget thing most of the time.

[PBrennick]

drhowarddrfine,
It is pretty much the same thing but it is generally used over serial connections.  It is Point to Point connection Protocol over the Ethernet and had its hey dey in the days before network adapters became commonplace.  The reason that your ISP is still using it, though, is it has one very useful feature, ALL the users, anywhere in the world, who connect to it use the same address, they need to have a unique quad number so they had you change the router default which you would have used for an internal PPPoe network.  You will have no problem, they solved it.  This method is a bit slower than TCp/IP but saves your ISP a ton of money and also saves you some money because they will not surcharge you for it.  As far as it being slower, it all depends on the amount of users on the PPPoe WAN (Wide Area Network as opposed to LAN which is Local Area Network and uses 1400).  You probably already rebooted your Router after making the changes so you know what your speed will typically be as this is the busiest time of the day (around 3:00pm).

EDIT:  BTW:  Write down those changes and put it in the filing cabinet.  A paper trail is safer than a computer file and you are right, we all forget.

Paul

[drhowarddrfine]

Up time is now 5 1/2 hours which is around two hours longer than I've ever had before so things are looking good.  The final test is if it's still up in the morning.  Then I'll be satisfied.  Thanks all!

[PBrennick]

Glad to help, it is fun.  I help whenever I am well enough.

EDIT:  Mark, the way to beat the ComCast problem is to install a second network adapter in the machine connected to the modem.  Hook your internal network to the second network adapter and do an internal route between the two network adapters and all the computers will be seen as one by the modem.  Very simple, actually, when you get the hang of it and it beats 'the man.'

Paul