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Subnet Mask, help, or something

Discussion in 'Networks & Internet Connectivity' started by KnightStalker, 23 Jul 2006.

  1. KnightStalker

    Soldato

    Joined: 27 Apr 2004

    Posts: 5,540

    Location: Doncaster, S.Yorks

    Hey guys, just a quick question, or maybe a long one, depending on how you see it

    Subnet Masks, do they have an impact on the router working???

    My RP614 router has been working 100% for god knows how long, and now it doesnt.....one thing that has changed is the Subnet Mask on the Modem, (i know this when i directly connect the modem to PC) it was the normal 255.255.255.0 but now the last .255 is now .254 and the router will not work, modem and router do not communicate, ive done the usual reboot of them all and messed around with the normal settings...


    I need help please.
     
  2. Ricochet J

    Capodecina

    Joined: 29 Jun 2004

    Posts: 12,906

    Subnet mask is very important as it tells the router/modem where to send traffic. The subnet mask has to fit in with the subnet address because otherwise the number of "borrowed" bits will not fit and the network part of the address will go bonkers.
    I guess, in a nutshell, the subnet mask tells the computer, which part of the address is a network portion, and which part is a host.

    Post your IP and subnet mask and required amount of subnets and i'll sort it out for you. :)
     
  3. KnightStalker

    Soldato

    Joined: 27 Apr 2004

    Posts: 5,540

    Location: Doncaster, S.Yorks

    i know how to get the ip and subnet, but what the heck is the amount of subnets?
     
  4. Imy

    Mobster

    Joined: 21 Nov 2005

    Posts: 2,771

    Location: Nuneaton, UK

    Can you just clarify if the subnet mask is now 255.255.255.254 or 255.255.254.0?
     
  5. KnightStalker

    Soldato

    Joined: 27 Apr 2004

    Posts: 5,540

    Location: Doncaster, S.Yorks

    255.255.254.0...sorry just reread my post, i dont think i made it clear enough, sorry my bad.

    but for the last 3 years, its been 255.0 at the end, working with the router fine. now it doesnt. seems strange
     
  6. Imy

    Mobster

    Joined: 21 Nov 2005

    Posts: 2,771

    Location: Nuneaton, UK

    The following is a rough guess as to whats happening:

    Since the subnet mask is set on your modem, this means its set by your ISP. By going from a subnet mask of 255.255.255.0 to 255.255.254.0 all they've done is restructure their subnets to have 510 usable hosts instead of 254. I'm not sure how this could cause a problem.
     
    Last edited: 23 Jul 2006
  7. KnightStalker

    Soldato

    Joined: 27 Apr 2004

    Posts: 5,540

    Location: Doncaster, S.Yorks

    oh screwy, i havent a clue whats gone off then, since that changed the router no longer wants to work, so its something to do with that, as its the only thing thats changed.
     
  8. Imy

    Mobster

    Joined: 21 Nov 2005

    Posts: 2,771

    Location: Nuneaton, UK

    You're not doing something silly like connecting the modem to your pc directly and to your router at the same time are you?
     
  9. KnightStalker

    Soldato

    Joined: 27 Apr 2004

    Posts: 5,540

    Location: Doncaster, S.Yorks

    nope, havent changed the cables in 3 years, they are still the same, so thats not it.
     
  10. Imy

    Mobster

    Joined: 21 Nov 2005

    Posts: 2,771

    Location: Nuneaton, UK

    What else have you tried to fix the problem?
     
  11. KnightStalker

    Soldato

    Joined: 27 Apr 2004

    Posts: 5,540

    Location: Doncaster, S.Yorks

    basically, ive rebooted the router and modem, at different intervals, modem first, router second, and then vica versa, ive tried setting manual IP's to no effect, ive Rang my ISP but they dont deal with routers (blueyonder), im at a real loss here, and from what i can see, its not something ive done, as the day it happened i wasnt even in.
     
  12. Imy

    Mobster

    Joined: 21 Nov 2005

    Posts: 2,771

    Location: Nuneaton, UK

    On your router's home page it says "connects up to 253 network users". That indicates a subnet mask of 255.255.255.0. Not sure if that's important. I'll have quick look at your router's manual. In the meantime you might want to try a firmware upgrade on your router.
     
  13. KnightStalker

    Soldato

    Joined: 27 Apr 2004

    Posts: 5,540

    Location: Doncaster, S.Yorks

    thanks, i thought it was something like that, i have the latest firmware, as Netgear havent released one for over a year, so god knows what im supposed to do now.
     
  14. Imy

    Mobster

    Joined: 21 Nov 2005

    Posts: 2,771

    Location: Nuneaton, UK

    I could be talking b**** you know - I didn't pay that much attention at uni :D

    Best to wait for replies from other users too.
     
  15. KnightStalker

    Soldato

    Joined: 27 Apr 2004

    Posts: 5,540

    Location: Doncaster, S.Yorks

    ok will do Imy, so anyone else want to help me out?
     
  16. Imy

    Mobster

    Joined: 21 Nov 2005

    Posts: 2,771

    Location: Nuneaton, UK

    Does your router pick up an IP address from the modem?
     
  17. KnightStalker

    Soldato

    Joined: 27 Apr 2004

    Posts: 5,540

    Location: Doncaster, S.Yorks

    thats the thing, when everything is connected correctly, i cant get to the router config page or modem page, the 2 seem to hate each other right at this moment, so im all confused, and im about ready to throw everything out the house and forget about all this internet stuff.
     
  18. Imy

    Mobster

    Joined: 21 Nov 2005

    Posts: 2,771

    Location: Nuneaton, UK

  19. KnightStalker

    Soldato

    Joined: 27 Apr 2004

    Posts: 5,540

    Location: Doncaster, S.Yorks

    that's correct
     
  20. Imy

    Mobster

    Joined: 21 Nov 2005

    Posts: 2,771

    Location: Nuneaton, UK

    Ok well thats a big problem!

    Try pushing the master reset switch on your router then try access that address again.