Mnemonics for Memorizing the Decision Process
Many people do not bother to memorize the BGP decision process steps. However, memorizing the list is very useful for both the CCIE Routing Switching written and lab exams. This section provides a set of mnemonic devices to aid you in memorizing the list. Please feel free to learn the mnemonic or skip to the next heading, at your discretion. Table 13-8 BGP Decision Process Mnemonic: N WLLA OMNI The first mnemonic step is to memorize the nine trigger letters—single..
Configuring Bandwidth over a Hybrid Multipoint Network
If the multipoint network has differing speeds allocated to the VCs, a more complex solution is needed. There are two main approaches: • Take the lowest CIR and multiply it by the number of circuits. Apply the product as the bandwidth of the physical interface. The problem with this configuration is that EIGRP will underutilize the higher-bandwidth links. • If possible, it is much easier to configure and manage an environment that has used subinterfaces, whe..
The primary reason for queuing is that a router needs to hold a packet in memory while the outgoing interface is busy sending another packet. FIFO queuing simply provides a software queue to hold packets while they are waiting to exit an interface. Packets are scheduled to leave the interface based on when they arrived at the output interface. Because IOS defaults to use WFQ on serial interfaces with bandwidths of E1 speeds (2.048 Mbps) or less, to configure FIFO queuing, yo..
You can use the ntp access-group command to restrict which devices you want your router to allow NTP associations with: Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#access-list 88 permit host 172.25.1.1 Router(config)#access-list 88 permit host 10.1.1.1 Router(config)#access-list 99 permit 172.25.0.0 0.0.255.255 Router(config)#access-list 99 permit 10.2.0.0 0.0.255.255 Router(config)#clock timezone EST -5 Router(..
Changing Privilege Level of IOS Commands
Cisco routers support sixteen privilege levels, ranging from zero to fifteen. By default, Cisco assigns commands to only three of these privilege levels: zero, user, and enable. There are five commands with privilege level zero: disable, enable, exit, help, and logout. The user level (privilege level 1) has a wide variety of commands available that cannot alter the router's configuration. Enable mode (privilege level 15), by contrast, allows complete access to all router comm..
