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Basic network and security questions

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A model citizen

Basic network and security questions


I believe I already know the answers, but just to confirm:
 
  1. At my home router, I have the sub net mask as 255.255.255.240 /28. This means, I can have 14 hosts on my network. What would happen if a 15th host try to connect to my network. It simply wouldn't connect? If another logs off, it can connect?

  2. What would happen if someone connects a router to my work network and setup their own network? Is there anyway to block it without going through each office and checking occasionally? I

4 REPLIES 4
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A model citizen

Re: Basic network and security questions

Sorry if I'm in the wrong section.  Feel free to move it to the correct sectio.

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Kind of a big deal

Re: Basic network and security questions

Lets pretend you were using 192.168.0.0/28.

 

There are 14 host IP addresses available, 192.168.0.1 though to 192.168.1.14.  One of these needs to be used by the home router, leaving 13 free for hosts.

 

If you were to setup up IP address allocation with a lease time of 7 days, then the first 13 devices to plug in and get an IP address would work.  The 14 device would fail to get an IP address.

If after 7 days one of those original devices was no longer plugged in and renewing its DHCP address then that address would be available for another device to use.

 

 

If you want to restrict what can be plugged in you would need to adopt a "deny all" policy where nothing is allowed access until you grant that access.  Then random plugged in devices wont work.

 

 

Also note that a /28 subnet for a LAN would be unusual.  This is a more typical WAN subnet prefix.

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A model citizen

Re: Basic network and security questions

@PhilipDAth 

 

Thanks for the reply.  You said, If you want to restrict what can be plugged in you would need to adopt a "deny all" policy where nothing is allowed access until you grant that access.  Then random plugged in devices wont work.  Is this something I can do on the Meraki?  The only Meraki device I have is the router, but all my switches are Netgear and UniFi.

 

Also note that a /28 subnet for a LAN would be unusual.  This is a more typical WAN subnet prefix.

I choose /28 in my home network because I wanted to restrict the number of devices that will be on my network, but yes I agree that /28 is unusual in a home network.

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Kind of a big deal

Re: Basic network and security questions

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