1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

IP Classes

Discussion in 'Networks' started by kelton, Sep 12, 2003.

  1. kelton

    kelton Nibble Poster

    83
    0
    4
    Can someone clarify this for me...

    Ive just gone over an explination of class IP addresses from my training material and got confused. Managed to sort some of it out but am still slightly confused.

    The class addresses were explained fairly simple like this:

    Class A IP address Range 1 - 126
    Class B Range 128-191
    Class C Range 192-223

    The next chapter explained about subnets which clarified a few things.... however, I was under the impression that the Internet used all class A, and class B and C were used for smaller networks.

    That means that all IP addresses on the internet have to be in the 1 to 126 range?

    So why is my own IP address 193.*.*.* and on a site I have IP access to I can see logins from 4.* to 208.* (and that is just a quick sample of 10 logins!).

    Surely mine is a class C address?

    I am aware that the netmask has a lot to play on it... depending on what it is set as (ie class C is 255.255.255.0).

    Is it not as simple as the nice table they gave us with ranges on? Can any class use any range now (apart from specificaly reserved ones like 127.* and in my knowledge 192.*) and its all down to the netmask what type of class it is?

    Thanks.... I hope that all makes sence!
     
  2. Jakamoko
    Honorary Member

    Jakamoko On the move again ...

    9,915
    60
    229
    Hi kelton,

    The Internet uses Classes A,B and C, hence you get a 193.*.*.*. My IP from my ISP is something like 231.*.*.*

    The restricted adds are 127 (loopback),169.254 (APIPA) and 192 (ICS).

    Subnetting only affects Private networks, not the Internet.

    Hope that helps - bit of a rushed answer :) And I'll stand corrected as always ....
     
    Certifications: MCP, A+, Network+
    WIP: Clarity
  3. SimonV

    SimonV Petabyte Poster Administrator

    6,616
    151
    228
    Last edited: Jan 2, 2015
    Certifications: MOS Master 2003, CompTIA A+, MCSA:M, MCSE
    WIP: Keeping CF Alive...
  4. AJ

    AJ Administrator Administrator

    6,771
    102
    221
    I know this is of little help but it has to be said:

    Wait until you start to use variable subnets. Then you'll start to see stars.

    try getting some of the cramsession files as they are very good.

    Andrew
     
    Certifications: MCSE, MCSA (messaging), ITIL Foundation v3
    WIP: Looking at doing ..................
  5. tripwire45
    Honorary Member

    tripwire45 Zettabyte Poster

    13,493
    179
    287
    Back when IP addressing and the internet were young, no one thought we could run out of IP addresses. Major blocks of Class A addresses were sold to major players in industry. This comprised of many more IP addresses than they would ever use. Still, these companies own those addresses and no one else can use them.

    Pretty soon, it became apparent that that WAN and LAN networking was going great guns. Oops. Too late did anyone realize that we could actually run out of addresses. All those Class A addresses sitting out there, gathering dust.

    We've tried to stretch our resources as far as we can by implementing Class A, B, and C addresses. We use NAT on our internal networks so we only need a few "official" IP addresses for going out to the internet.

    There's even a "buy back" program in place to try and recover some of the IP addresses originally sold but not in use. With variable IP addressing, we can use addresses in a classless manner (I don't want to write an entire lesson right now. It would take up a lot of room...it's late (for me in my time zone, anyway), and you'll learn about this stuff as you continue to study.

    What's gonna save our butts is IPv6. It's really neat stuff, but we'll have to change our way of thinking about IP addressing. We now do addressing in four octets, using a decimal numbering system for convention (all IP addressing is really binary as you know). IPv6 will make us all have to think in hex. :eek:

    Here's a link for more info:

    http://www.ipv6.org/

    Oh, one more thing. Visit this link: http://www.learntosubnet.com/

    It's a really good tutorial for learning to subnet. For a very nominal fee, you can buy the site content on a cd so you can study off line. It really helped me when I was studying for my CCNA. Good luck.
     
    Certifications: A+ and Network+
  6. Luton Bee

    Luton Bee Kilobyte Poster

    365
    0
    36
    IP V4 address classes map to the bit settings in the first octect thus:
    0xxxxxxx = Class A 0-127
    10xxxxxx = Class B 128 - 191
    110xxxxx = Class C 192 - 223
    1110xxxx = Class D 224 - 239
    1111xxxx = Class E 240 - 255

    Although the use of CIDR (classless internet domain routing) has largely made the class of IP address irrelevent in all but private network addressing schemes. Subnetting is simply the moving of the "line" that differentiates between the network and host portion of an IP address. The "line" is where the subnet mask stops being a one when written in binary (eg 255.255.255.0 in binary is 11111111.11111111.11111111.00000000 so the 24th bit is the last one hence it's sometimes written as /24) wherever this line comes everyting to the left is the network address and to the right is the host address. If I want to split this up so that the IP address can support more than one network address I simply borrow bits for the host address portion, if I borrowed one bit it would change the subnet mask to 11111111.11111111.11111111.10000000 or 255.255.255.128 in decimal.

    HTH
     
    Certifications: MCSE, MCSA, MCP, A+, Network+ C&G ICT
    WIP: CCNA
  7. flex22

    flex22 Gigabyte Poster

    1,679
    0
    69
    Kelton, if you haven't got it already, buy Mastering Windows 2000 Server by Mark Minasi.

    I've just been reading the chapter on IP addresses and he explains it very well.

    I've visited learntosubnet and that helped me.I wanted to order the complete series on CDROM but it takes about 9 years to get to little 'ol merry England and the import tax you'd have to pay would probably be 3x more than the cost of the product.

    Nethertheless, if you can wait for it, then I'd say, get it.
     
  8. kelton

    kelton Nibble Poster

    83
    0
    4
    Thanks, a lot of help here :)
     
  9. tripwire45
    Honorary Member

    tripwire45 Zettabyte Poster

    13,493
    179
    287
    You also might want to read Ian McLean's Windows 2000 TCP/IP Black Book. Here's the link: http://www.amazon.com/exec/obidos/tg/detail/-/157610687X/104-3261891-5793511?v=glance Ian also has the "hometown advantage" with most of the members of this forum is that he's in Scotland. Born and bred there to the best of my knowledge. "TCP/IP" is a huge tome, but Ian threw in just about everything but the kitchen sink. It's been a huge help to me so far and I've barely scratched the surface.
     
    Certifications: A+ and Network+
  10. flex22

    flex22 Gigabyte Poster

    1,679
    0
    69
    That Black book looks interesting.

    I've just checked it out.It costs around £35.

    I can't really afford that but if you really think it's worth it then I'll look into it.

    Are there any free sample chapters that you know of, so I can get a feel for the book.

    Thanks!
     
  11. tripwire45
    Honorary Member

    tripwire45 Zettabyte Poster

    13,493
    179
    287
    Here's a link to amazon.com where you can read up to 56 sample pages from the book:

    http://www.amazon.com/exec/obidos/t...;s=books&vi=reader&img=16#reader-link

    What's that translate into as US dollars? On the links from Amazon, I can find it used for as little as $5.00 and new for $8.98. I know amazon has a uk vendor so I can only imagine that the pricing should be pretty much as reasonable.

    I consider the book a techie "classic". The original publisher Coriolis went out of business, but another publisher bought the rights and are selling it under their label. I found what is apparently a later addition crediting Ian and another author. It's possible that the current rights owner hired another author to write an update. Ian, of course, won't see a dime for any of this.

    I'm fairly confident that you could find a Coriolis copy of TCP/IP for a pretty reasonable price if you look at used techie book vendors on line. Let me know if you can't and maybe I can pick up a copy cheap here and just mail it to you.
     
    Certifications: A+ and Network+
  12. Sandy

    Sandy Ex-Member

    1,091
    2
    65
    IMHO If you really want to understand Windows 2000 networks Ian's book is THE book. I would go as far to say that to pass 216 you really need this book.

    I know he is a fellow Scot and a really nice man but take a serious look at this book :!:
     
  13. Sandy

    Sandy Ex-Member

    1,091
    2
    65
    Flex

    Use Amazon MARKETPLACE where you will find 2nd hand books for a lot cheaper that the new price. In fact I have several books for sale there. :idea:
     
  14. Phil
    Honorary Member

    Phil Gigabyte Poster

    1,680
    7
    87
    I haven't been on Certtutors for a while now, does Ian still post on there?
     
    Certifications: MCSE:M & S MCSA:M CCNA CNA
    WIP: 2003 Upgrade, CCNA Upgrade
  15. Sandy

    Sandy Ex-Member

    1,091
    2
    65
    Phil

    Yes Ian still posts :D
     
  16. flex22

    flex22 Gigabyte Poster

    1,679
    0
    69
    Advice like that is priceless and the reason why I love these cert sites.

    Thanks :!: Sandy.
     
  17. Taz69

    Taz69 Byte Poster

    125
    0
    26
    Certifications: MCSE: S, MCSA:M, MCSA: S, Net+ & 70-284
    WIP: MCSA 2003 & MCSA:Messaging 2003
  18. tripwire45
    Honorary Member

    tripwire45 Zettabyte Poster

    13,493
    179
    287
    If Ian's book isn't currently considered a classic, I think it eventually will be. That's kind of hard to see when you're talking about technical books since technology changes from day to day, but Ian really threw in everything but the kitchen sink on this one.

    He still posts at http://www.certtutor.net/forums and has a new book out and you can find it here: http://www.amazon.com/exec/obidos/t...8_1/103-2410680-5467868?v=glance&n=507846.

    Oh...another networking tutorial site where you can learn more about addressing and subnetting is RAD University: http://www2.rad.com/networks/netterms.htm
     
    Certifications: A+ and Network+
  19. flex22

    flex22 Gigabyte Poster

    1,679
    0
    69
    How weird is that :!:
    I've just been thinking about this book this morning, because I want to understand TCP/IP better.
    I was going to come on the web and see if I could find it anywhere cheaper.

    So I check out certforums before I do that, and Taz the man has posted where I can get the book cheap.

    Now that's what I call service :thumbleft
    :super
     

Share This Page

Loading...