Internet Slow Through Router

I have Comcast 10mbps internet service. When connected through my router my service is VERY slow. Resetting router and modem solves the problem temporarily (about 2-10min)

My internet speed (as tested at
-Using my Netgear WRG614 v9 wireless router = 250-900kbp & 600ms ping
-Directly connected to my cable modem = 10-15mbps & 60ms ping

I have five PCs on my network which reproduce this problem (3 wireless and 2 wired.) Comcast sent out a technician who checked my line and replaced my modem. Nothing fixed.

Here's what I have tried:
-Upgraded to latest Netgear firmware
-Replaced Netgear WRG614 v9 with Linksys WRT54g2
-Installed DD-WRT firmware on Linksys WRT54g2
-Cloned MAC address of my PCs (the alternate MAC is supposed to register the modem on the network differently and possibly route the traffic differently)
-Adjusted MTU settings
-Replaced Ethernet Cables
-Put distance between equipment (Electrical Noise)
-Changed local ip address range
-Disabled wireless

ALSO: When I have the MAC address of my router cloned to my PC I can switch the ethernet cord between the modem and my PC and still remain online without having to restart the modem or router. Immediately upon switching to the router (BOTH The Netgear and Linksys) my speed is significantly slower.

Here are just a few of threads I have checked out

MTU Setting
Electrical Noise

I have spent over 10 hours trying to solve this problem. Any suggestions?
13 answers Last reply
More about internet slow router
  1. Have you tested with only one computer connected to the router?
  2. Hey jtreibick,

    I am experiencing the same exact problem you are, with the Linksys WRT54G and DD-wrt. Aside from MAC adress cloning, our setup looks the same. I'm connected currently with only 1 computer, but I have several I need to connect. I know it's been a long time since you post this, but maybe you found a solution?

    Thanks in advance,
  3. Same problem here, Ive been looking for a solution for a week. Have not tried the MAC address clone but I have a similar setup using DDwrt v23 sp2 on WRT54G ver 1.0

    here are my memory stats:

    Total Available
    13.8 MB / 16.0 MB
    3.0 MB / 13.8 MB
    10.9 MB / 13.8 MB
    1.4 MB / 10.9 MB
    4.4 MB / 10.9 MB
    3.3 MB / 10.9 MB
    2.5 MB / 10.9 MB

    I get 22mbs when connected to my DOCSIS 3 SB6120 according to - The modem link light also turns blue to indicate gigabit connection. When connected to the router single user via cat5 I get a max of 17mbs, and when connected with one computer via Wireless-G It goes no higher than 10mbs (even lower when on the other side of the house).

    Im considering getting a gigabit N router but I dont understand why I would need to. I thought G can do 54mbs? Is the processor just too slow on the router? Does it need a gigabit connection? Why does it suck?

    I have another WRT54G and had the exact same results. I really would prefer to not spend $70 on a router and spend it on fun instead.

  4. Actually - I just posted something similar - I traced my issue to the firewall in my router. Have you tried turning off the firewall to see if that might be the issue.

    I'm trying to find alternative routers that have a better in-unit firewall or faster processor, I don't want to put a standalone box out there for that purpose - I will if necessary - but don't want to. My router is an Linksys RVL200 and I drop from 9.8Mb to 3.5Mb when the firewall is turned on (it's always on btw - I just turn it off when testing for this problem.)

  5. Hey guys, I know this is really old but I found this while googling the problem. Someone above mentioned disabling the firewall, and this worked for me. I have a linksys wrt54gs and am running dd-wrt. My download speed went from about 1 Mbps to Mbps 14 once i disabled the firewall.

    I dont really want to leave my network exposed though, anyone know what exactly might be causing this in the firwall settings? Thanks.

    Hope that helps.
  6. If changing the firewall setting makes that much of a difference you need to change your firewall / firmware. Have you tried just running the stock Linksys firmware to see if the problem occurs with it? If so... I'd highly recommend upgrading to a new router that's got the power to push that traffic. 1mpbs is pretty slow for a stateful firewall. You could also build out a Linux box with two interfaces and run iptables on it. That's what I used to run before I got my ASA and performance was always pretty good...
  7. Just wanted to say I was having the EXACT SAME problem with a 610wrt linksys/cisco wireless router & a rcn connection. I have disabled my firewall and this solved all my bandwidth issues.
  8. I'm having pretty much the same problems as described throughout the thread with some minor variations.

    1) I'm running a Linksys WRT54G v8 with their latest firmware upgrade.

    2) I have disabled the router firewall -- didn't help much. Cloning the MAC address didn't do anything useful either.

    3) I've noticed some correlation with time of day. Things seem to be fairly normal most of the day, but then go South about 4PM EST each day.

    4) I've noticed some variation depending on the destination site. When I try to bring up it's quite fast (always). Also when I bring up :) However, (and various others) is quite slow.

    5) I've noticed some correlation between home page load time and the number of images on the page. Quite often the status bar shows the "(n) items remaining ..." message on pages like Microsoft home or other sites that have busy home pages.

    6) Quite frequently, when the page load appears to be hung, hitting the browser refresh button seems to clear it. That's a real nuisance, but it seems to be helping get the job done until the real answer emerges.

    Could Comcast be "throttling" some stuff after winning their recent court case?
  9. 3 Factors to consider with Cable Modems.

    Quality of signal over coax to modem.

    Are there Splits off your main line? More than one is bad.

    How many people in your area have it, when area traffic is high, speed will lag.

    Routers have a built in firewall, so does windows, plus a 3rd party one. 2 or more firewalls = Conflict, very bad. Disabling one, will not expose you, unless you port forward your machine. Test your connect this way, disable all firewalls, and place your machine in the DMZ, then run the speedtest

    I hope someone gets value from this

    Checked network and one PC had a torrent application running on it... this was causing the issue for me.
  11. What about the NIC speed? Would it help is you set your NIC to 100Mbps Full Duplex instead of Auto Configure/Auto Detect?
  12. Disabling QoS in my wrt54gl router running dd-wrt seemed to fix some of the slowdown for me.
  13. This topic has been closed by Mousemonkey
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