SDramatic LAN Speed cut with Router attached to Ubee Cable Modem

[grahambr]

Hi All...

I have a very weird issue.

As of this morning, with NO changes to settings or anything, my internet speed dropped from 35mbps to .33mbps.

Here is what I did to trouble shoot:
1) I attached a PC directly to the Cable Modem. I then Got 35mbps!
2) So I changed Ethernet cables to the router
3) Reset the router to defaults
4) Hooked it back to cable modem and dropped to .33mbps
5) So I thought it was the router. I replacd it with a brand new one. Factory fresh...hooked up... .33mbps.
6) So perhaps it was the netgear modem... so I hooked up a DLINK. .33mbps
7) I hooke dthe computer directly to the cable modem again and I get 35mbps!

I have a Netgear WNDR4500. The Cable modem is an UBEE (Also does Phone). This is all on a WIRED connection. On WIFI, it is just as slow. The cable modem is BRIDGED.

BrightHouse is sending a giuy out on Monday to replace the cable modem as they have no idea what is wrong... but I just dont understand how it could be the cable modem. But seeing as how I tried 3 routers... I dont see how it is the router either.

I also replaced cables just in case. I cloned MAC Addresses. Turned off all quality and firewall settings.

Nothing.

This JUST started last night. It was perfectly fine prior.

Im at a loss.

Any ideas? I would think that if the cable modem is outputting 35mbps, the router should be fine. Its almost as if the cable modem is sensing the difference between a router or a computer being connected and cutting the speed...but I dont know if that is even possible?

ANY help would be appreciated....

 

[eibgrad]

Try this. Disable the router’s DHCP server. Patch the router to the modem, but connect it using a LAN port, NOT the WAN. And then connect one PC to a second LAN port.

[modem]<-- wire -->(lan)[router](lan)<-- wire -->[pc]

The idea is to use the router, but only the switch. I just want to see what happens if the router is used, but only in the most benign way; no routing, just switched. Let’s see want kind of behavior we get.

 

[grahambr]

Try this. Disable the router’s DHCP server. Patch the router to the modem, but connect it using a LAN port, NOT the WAN. And then connect one PC to a second LAN port.

[modem]<-- wire -->(lan)[router](lan)<-- wire -->[pc]

The idea is to use the router, but only the switch. I just want to see what happens if the router is used, but only in the most benign way; no routing, just switched. Let’s see want kind of behavior we get.

I just tried it and the PC doesnt get an internet connection at all. I will try changing the setup again and rebooting the cable modem.

 

[eibgrad]

Make sure the router's DHCP server is disabled or else it won't get the public IP, only a private IP. I assuming, of course, the PC has DHCP enabled too. You may have to reboot the modem a few times too. Sometimes the last device to have the public IP tends to hold on to it unless its lease was formally released.

 

[grahambr]

Try this. Disable the router’s DHCP server. Patch the router to the modem, but connect it using a LAN port, NOT the WAN. And then connect one PC to a second LAN port.

[modem]<-- wire -->(lan)[router](lan)<-- wire -->[pc]

The idea is to use the router, but only the switch. I just want to see what happens if the router is used, but only in the most benign way; no routing, just switched. Let’s see want kind of behavior we get.

Yeah... I disabled the DHCP, connected the cable to port 4, rebooted the modem, but I dont get any internet connection.

 

[eibgrad]

What does your PC's tcp/ip configuration report (run "ipconfig /all" (no quotes) from a DOS prompt)?

 

[grahambr]

What does your PC's tcp/ip configuration report (run "ipconfig /all" (no quotes) from a DOS prompt)?

I am using a mac. I am going to try and replicate it tomorrow on my windows laptop. I tried it many many ways and rebooted the modem many times and could not get an internet connection at all. I know that i renewed the lease and got a 169.xxxx addresss... the modem is a 91.xxx address...

What I am going to do tomorrow is this:

1) Go directly to the modem to my laptop and get the IP information
2) Hook up the modem to the router in non dhcp mode and get the ip information from the laptop
3) Have my friend bring his cable modem over and see if that makes a difference

I. just. dont. get. it.

The problem is also that I cannot get into the cable modem to see how it is configured at all...so that part is in the dark to me.

 

[grahambr]

Problem solved! It was in fact the cable modem. WEIRD! Swapped out the cable modem and all is back to normal...just like that!

Thanks for the help.

 

[eibgrad]

Good to hear, thanks for reporting back.