APPENDIXES Appendix A Appendix B Appendix C MAC Address Filtering 802.11n Wireless Channels 802.11 Additional Revisions We end the book with a few appendixes. You do not need to read these unless you are curious about MAC address filtering, 802.11n wireless channels, or revisions to 802.11. Appendix A, "MAC Address Filtering," shows you how to add MAC filtering to your wireless net- work security. MAC filtering can be a bit difficult to implement and maintain, so we chose not to make it a core part of the security steps you should take. Instead, it is offered as an optional security measure.