Can I let AirPort use several IP's?

Discussion in 'Mac Basics and Help' started by iMacZealot, Aug 17, 2006.

  1. iMacZealot macrumors 68020

    Mar 11, 2005
    I have an AirPort Express and Comcast High Speed Internet, and it's a dynamic IP, or so the guy who set it up told me. I found my range of IPs on a WHOIS site and was wondering if I could modify AirPort to lease them to users instead of sharing the same one. Whenever I type in my range in the AirPort Admin Utility thingy, it says "Sharing a rance of DHCP addresses requires the base station to be configured using static IP addresses". Is there any way I can use all of my IPs? The reason why I want to lease several IPs is because the coverage in my house shrinks and the internet becomes slow whenever I have guests and the rest of my family comes here.
  2. gothicx00 macrumors member

    Aug 7, 2006
    I think you may have a misunderstanding of the technologies at hand. If you have a router, when it talks to the rest of the internet, the rest of the internet sees the public IP address that comcast leases to your modem. When you connect to the router, the router in-turn leases you (and anybody else connecting) a private IP, usually starting with something like 192.168.xx.x

    Each person connected to the router gets a seperate private IP address, but to the rest of the internet, any requests sent out by anybody looks like it's coming from the public IP address. That slowdown (i'm asuming everyone is connected wirelessly) is because the bandwidth to the router is saturated. There isn't really any way to avoid that.

    To make matters worse, is if your Airport is running in G mode (54mbs) and anybody that only has an A or B wireless card connects, the whole thing slows down to accomodate their speed. If that is indeed the case there is a great way to solve this. Get an inexpensive router, maybe one that is only compatable with the B protocol. Connect the AP Express to one of the router's ports and connect the router to the modem. Then configure the Airport to only accept G connections. Then make sure the cheapo router is not set to auto channel mode. Set it to either 1, 6, or 11. Then set the airport to manual channel mode as well, and pick a different channel from 1, 6, or 11. Those are the only three channels that do not overlap. That way, you are not bogging down your 54mbs traffic, whilst still allowing A and B traffic to take place.

    Contrary to popular belief, your Mac will work on other routers besides the Airport Express. I'm connected to a Buffalo WHR-54GS. Works great!
  3. iMacZealot thread starter macrumors 68020

    Mar 11, 2005
    Alright that makes sense. Thanks. I think it's the AirPort that's slowing things up. At Christmas, I'll have up to 8 or 9 computers (Mac and PC) connecting to the AirPort Express. My dad's Toshiba Tablet has an 802.11b card which has been replaced time after time and still is sluggish, which I think that card is slowing things up, too. My iMac G3 also has a B card, but is never used that often. Most of the time, I have my iMac G5 (G), the Tablet (B), the Gateway (G), and my sister's Dell laptop (G, I think) connecting.

    EDIT: Oh, and by the way, should I set my AirPort to a specific channel then? Will I get faster internet?
  4. gothicx00 macrumors member

    Aug 7, 2006
    Setting the channel to a manual channel could help, but only if there are other active wireless AP's nearby. But what i'd do is download a copy of kismac and see if you can pick up any other AP's in the area, and what channels they are running on. Like i said previously 1, 6, and 11 are the best by far. If most everyone is running on 6 (default btw on most routers) run 1 or 11. Just use that system to stay away from the other AP's in the area. Most routers can handle being interfered with a bit, but too much will send it over board, and cause connection problems. My personal favorite channel, if you wanted to know, is 11. It's higher up on the spectrum and can typically handle physical interference better (i.e. walls, couches, cats, etc.)

    Another thought is if you only really experence the serious slowdowns when they are in town, get one of them to bring their own router with them. Then you could temporarily rig it up to have a dual band system.

    But if you randomly experience these slowdowns with no obvious cause, you might want to check the security settings on your Airport. If it's only using WEP that's bad. I can crack WEP in about 15 seconds flat, given the right conditions. WPA is better, WPA2 is the best. Having never personally played with an Airport Express, I can't quite walk you through the settings. But i'm willing to bet there are tons of great guides out there for it.

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