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I have a modem which used for internet broadband and I got an IP address in the 'A' class 10.x.x.x and have netmask

  • What does mean exactly?
  • When I try to sniff with promisc mode, will this 'netmask' never allow me to do such to try things?
  • What is the dhcpcd configuration so that each client get the subnet mask
    (For example: By MAC Address)

Thanks in advance, guys! :-)

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Welcome to Super User! Please note, @capede, that your original question has been answered as is, the details you have added make it unclear what you are exactly trying to do. Could you please describe your overall goal instead of specific details? – Tom Wijsman Jan 30 '11 at 18:05
Addressing is no longer classful and the addresses in 10.x.x.x are in a private range. – Dennis Williamson Jan 30 '11 at 21:49

It means that your phone is using a point to point link. All your outgoing traffic will be routed to the other end of your link and nothing will be sent to the local network, which is unsurprising as there is no local network.

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A network with a subnet mask of puts each device inside its own subnet, forcing them to communicate with the router before communicating with any other device.

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  1. If you assign that as your subnet mask, it is no longer a network but a standalone host which could not communicate on the interface where it has been assigned

  2. As you can not communicate, prominiscious mode will not work at all.

  3. See the man page for dhcpd.conf, you can do this by grouping hosts in a group and then assign.

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An address with a may be one end of a PTP (point to point) tunnel. Check your routing table using a command like netstat -rn. You may see a route to another address from your IP. The other address should have a route to (the default route).

share|improve this answer isn't an external IP, it's a LAN, VPS, etc (Hamachi is the main use of it) address. You need a non-LAN global ip address, your router should be doing this as it is your gateway, and you can have a internal IP like yours and still be on the internet, so this isn't your problem. What is your modem? What have you changed since you got it?

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'and you can have a internal IP like yours and still be on the internet, so this isn't your problem.', how come sir ? what is my modem? do you mean the vendor sir? my modem is haier C100, i changed nothing just run 'wvdial' in order to established my internet connection on host A ( eth0 , really looking forward for your leap of faith of answers sir :D – capede Jan 30 '11 at 18:18

It probably means you're using PPPoE. PPP links are commonly created using 32-bit netmasks.

It doesn't affect your Internet connection in any measurable way.

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That mask means host only address. It means you are on the end of a point-to-point link, and are not routed through.

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