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..
Load Balancing Across PortChannels
When a switch decides to forward a frame out a PortChannel, the switch must also decide which physical link to use to send each frame. To use the multiple links, Cisco switches load balance the traffic over the links in an EtherChannel based on the switch’s global load-balancing configuration. Load-balancing methods differ depending on the model of switch and software revision. Generally, load balancing is based on the contents of the Layer 2, 3, and/or 4 headers. If load ..
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..
Setting the IP Source Address for SNMP Traps
To set the default IP source address for all traps leaving a router, use the following configuration command: Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#snmp-server host 172.25.1.1 ORATRAP Router(config)#snmp-server trap-source loopback0 Router(config)#end Router# Normally, when you enable SNMP traps to a remote server, that server will see the source IP address of the router's closest interface. However, this..
