The most obvious way to troubleshoot DHCP installations is to type show run and compare the output to this book. This approach, however, can fail due to a lack of details. A more robust way to troubleshoot is to examine the process step-by-step as assignments are made. Before discussing troubleshooting, we need to rule out some issues. We assume, in this section, that the PC has been shown to have a connection to the network, and the DHCP server is turned on. ..
The 802.11i working group has improved the security of 802.11 wireless LANs with an update to the 802.11 standard in 2004. The Temporal Key Integrity Protocol, for example, fixes the keyreuse problem of WEP. The TKIP process begins with a 128-bit “temporal key” shared among clients and access points. TKIP combines the temporal key with the client’s MAC address and then adds a relatively large 16-octet initialization vector to produce the key used to encrypt data. This..
EIGRP uses a sophisticated metric that considers bandwidth, load, reliability, and delay. That metric is Although this equation looks intimidating, a little work will help you understand the math and the impact the metric has on route selection. You first need to understand that EIGRP selects path based on the fastest path. To do that it uses K-values to balance bandwidth and delay. The K-values are constants that are used to adjust the relative contribution of t..
Integrated Services Digital Network (ISDN) is used by telephone companies to carry digitized voice and data over the existing telephone system. ISDN has emerged as one of the leading technologies for telecommuting and remote office connection into the corporate headquarters. On the seven layer model, ISDN operates at the physical, data link, and network layers. ISDN basic rate interface (BRI) provides two barrier channels (commonly referred as B channels). Each of these B ch..
Sometimes, the Cisco enable or secret password is unknown and thus you must use password recovery to attain or change the enable or secret password. Password recovery allows the network administrator to recover a lost or unknown password on a Cisco router. For password recovery, an administrator must have physical access to the router through the console or auxiliary port. When an EXEC user enters an incorrect enable password, the user receives an error message similar to th..
