#1
  1. 300lb Bench!
    Devshed Regular (2000 - 2499 posts)

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    Don't understand what the /xx part of an ip address is supposed to means


    I thought I did. So if you have an ip address like 70.40.20.15 (just making one up, don't know where it points to), that's supposed to be a class A ip address and the subnet mask should be 255.0.0.0, correct? I would expect the ip/subnet info to then be listed as

    70.40.20.15/8

    I ask because I have an amazon aws and I try to limit which ip addresses can shell into it. So using the above example, I tried creating a rule with

    70.40.20.15/8

    but aws said it had to be

    70.40.20.15/32

    Ok, so after all of my googling clearly I have no clue what the final /xx is supposed to mean. Can anybody clue me in?
    Correspondence chess
    nothingbutchess.com
  2. #2
  3. Did you steal it?
    Devshed Supreme Being (6500+ posts)

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    That's CIDR notation. 70.40.20.15/8 and 70.235.189.2/8 are the same thing, both representing 70.x.y.z and the netmask 255.0.0.0. AWS might not like the fact that you used actual numbers for the X, Y, and Z (ie, that you had bits set) - try 70.0.0.0/8.
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    Devshed Regular (2000 - 2499 posts)

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    Ok, that worked as well. Thanks for the quick reply. I'll read the link you posted to learn more about this. Thanks for educating.
    Correspondence chess
    nothingbutchess.com

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