[c-nsp] against arp spoofing

[Monty Ree]

Hello, all.
 
I'm a begineer of the list and network.
I have read some articles that attacker can do sniffing in spite of switch environment, or do Dos  using arp spoofing.(some weeks ago, an attacker sent spoofed mac address to broadcast , so all network was down.)
 
So I would like to set static arp like below at my router or L3 switch. 
 
config)#arp 1.1.1.1 aaaa:aaaa:aaaa
 
But I have about 800 machines, if when I set all 800 arps like above, router requires more memory or not..? Is it a bad idea?
What do you do against arp spoofing? port security?
 
 
Thanks in advance.

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