What's the best network simulator for educational purpose?
What's the best network simulator for educational purpose? I want to use it to help students lean the basic network concepts, such as LAN, WAN, IP addressing, network layers etc. 

Thanks.
What's the best network simulator for educational purpose?
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What's the best network simulator for educational purpose? I want to use it to help students lean the basic network concepts, such as LAN, WAN, IP addressing, network layers etc. 

Thanks.