Results 1 to 5 of 5

Thread: Swapped Modems, same model, static WAN IP, Router couldn't reconnect

  1. #1
    Junior Member
    Join Date
    Mar 2017

    Swapped Modems, same model, static WAN IP, Router couldn't reconnect

    No Firewall in Router or in O/S
    Static IP addresses for all my devices except for a ATA (Obi202)
    Nothing special or fancy in the LAN.
    All wired except for a Laptop.

    Long story short, I swapped identical Modems that gave a static WAN IP address (yes it was static!) Both had a RF connection, new one showed connected. I moved the Router cable to the new modem with no reboot of the Router.

    No connection to the Internet. I rebooted the Router, still nothing. I then noted there was IP assigned. I did a DHCP release and renew twice. Still nothing.

    I then reset the Router (which I didn't want to do), still nothing. No WAN IP assigned still.
    I changed the LAN start IP adress from 100 to 2 since I use static IP address and after a minute the Router finally received a WAN IP address.

    1. Going from one identical Modem to another that passes an IDENTICAL IP address to the Router, is it still necessary to reboot the Router?
    2. Even after rebooting, why wasn't there connectivity between the Modem & Router, even thou the Modem 'Link' LED showed connected and with activity?
    3. After the Router reset, is spite of the LAN starting address at 100 which was outside of the static IP's of my devices, why didn't the Router get the WAN address from the Modem??

    Spectrum ISP
    Zoom 5341J Modem
    TP-Link WDR-3600 Router running dd-wrt firmware

  2. #2
    Moderator YeOldeStonecat's Avatar
    Join Date
    Jan 2001
    Somewhere along the shoreline in New England
    Did you get this modem from your ISP? If not, did you call your ISP to have them provision it?
    MORNING WOOD Lumber Company
    Guinness for Strength!!!

  3. #3
    Junior Member
    Join Date
    Mar 2017
    No and yes of course.

    One thing (other than your question) is when the new Modem was provisioned/authorized, the Router was not connected at the time since I have VoIP and I wouldn't of been able to make the call in the 1st place. (no toy phone here).
    I have done a swap before with no issue, same setup. Different other Modem, but both had RF connected.

  4. #4
    Second Most EVIL YARDofSTUF's Avatar
    Join Date
    Nov 2000
    I would unplug the modem and power it back on so that it tries to connect while hooked up to your router, comcast seems to like it being that way so it sees the routers MAC address.

  5. #5
    Junior Member
    Join Date
    Mar 2017
    The new Modem was powered on. It was not connected to the Router or a PC.
    The old Modem was still connected to the Router.
    Except for the 'Link" light, all four indicators were lit in a normal/active state making one think it was already activated.
    I called gave him the MAC address, he activated it, I watched the lights cycle, the call was disconnected (I have VoIP and was using that for the call).
    I moved the Router cable from the old to the new, NOT rebooting the Modem (purposely), checked for Internet access, but nothing.
    Rebooted the Router, still nothing, rebooted everything, still nothing.

    Off time was 20-30 seconds.

    I eventually got things back, but never had this problem before after 5 or 6 other swaps throughout the years.

Similar Threads

  1. Into model trains? Largest model train set up the world
    By YeOldeStonecat in forum General Discussion Board
    Replies: 6
    Last Post: 08-13-09, 09:40 AM
  2. Speed issues with Belkin router model FD5D7230-4 and F5D7000.
    By Rocky_Grim in forum Wireless Networks & Routers
    Replies: 0
    Last Post: 06-29-07, 03:21 PM
  3. How do I set a static IP on my router?
    By xaethia in forum Wireless Networks & Routers
    Replies: 1
    Last Post: 05-12-07, 06:36 AM
  4. Static IP on Wireless Router
    By Razor in forum Wireless Networks & Routers
    Replies: 6
    Last Post: 08-10-06, 01:47 AM
  5. How to set up static LAN ip's with a router...
    By Brent_212 in forum General Broadband Forum
    Replies: 3
    Last Post: 11-10-00, 05:16 PM


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts