How can you change your IP address in Mac OSX and change it back without losing your connection?

Need to do this to reset the cable modem on occasion.How can you change your IP address in Mac OSX and change it back without losing your connection?
Yo, when changing the ip address the system will reset the connection because it is now accesing the network with a different identity. You should check out the cable modem, it should alow constant connection without a reset.How can you change your IP address in Mac OSX and change it back without losing your connection?
You should not have to do this. The modem should maintain a constant connection.

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