Geographical Restrictions Pressure
In addition to the reliability motivation, companies might feel geographical pressure toimplement redundancy. Many contemporary companies are national, international, ormultinational in nature. For them, the autonomous system is a logical entity that spansdifferent physical locations. A corporation with an AS that spans several geographical pointscan take service from a single provider or from different providers in different regions. InFigure 7-1, the San Francisco office of..
Most access points and radio cards allow the setting of transmit power. The highest value is generally 100 mW (0.1 W), with increments of lower power available. Some devices enable settings as low as 1 mW. In most cases, it is best to set all wireless LAN devices to the highest transmit power, which is generally the default setting. To configure a wireless LAN for optimum capacity, you can set the transmit power to a lower value, which effectively reduces the size of the rad..
Confidentiality and Security Are Not the Same
Confidentiality and security are not the same. Here is a working definition of the two terms: Confidentiality is the protection of information to ensure that it is not disclosed to unauthorized audiences. Security is the protection of systems, resources, and information from unintended and unauthorized access or misuse. The difference is clear: security is a superset of confidentiality because it goes beyond protecting information by also protecting system functions and pr..
Setting the Router As the NTP Master for the Network
There is no need for a dedicated NTP server; you can pick one or two routers to act as authoritative NTP servers for the whole network. (The router should have a calendar function): Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#clock timezone EST 5 Router(config)#clock summer-time EDT recurring Router(config)#clock calendar-valid Router(config)#ntp master 8 Router(config)#end Router# When no authoritative time s..
DHCP-Secured IP Address Assignment
To enable secured IP address assignment, use the update arp command:Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z.Router1(config)#ip dhcp pool OREILLYRouter1(dhcp-config)#update arpRouter1(dhcp-config)#endRouter1#Beginning with IOS Version 12.2(15)T, Cisco introduced the concept of DHCP secured IP address assignment. This feature synchronizes the ARP entry to the DHCP binding to ensure that IP addresses assign via DHCP can'..
