STP Configuration and Analysis

Example 3-1, based on Figure 3-6, shows some of the basic STP configuration and show commands. Take care to note that many of the upcoming commands allow the parameters to be set for all VLANs by omitting the VLAN parameter, or set per VLAN by including a VLAN parameter. Example 3-1 begins with SW1 coincidentally becoming the Root switch. After that, SW2 is configured to become root, and SW3 changes its Root Port as a result of a configured port cost in VLAN 1. figure..

Requirements and Constraints

Before delving into the typical topologies, it is wise to understand the overall network design process. As with any systems design effort, network design is an exercise in meeting new and old requirements while working within certain constraints. These constraints include money, labor, technology, space, and time. In addition, there may be social or political constraints, such as the mandated use of certain standards or vendors. Economic constraints play a major role in an..

Automating Dial Backup

This recipe includes several important features. First, notice that we have configured dial backup using an ISDN BRI interface on this router. So we have to set up the ISDN configuration: Router1(config)#interface BRI0/0 Router1(config-if)#isdn switch-type basic-ni Router1(config-if)#isdn spid1 800555123400 5551234 Router1(config-if)#isdn spid2 800555123500 5551235 This site is connected to a National ISDN switch. So we have defined the switch type to be basic-ni. If this h..

Controlling Congestion with WRED

The syntax for configuring WRED changed with the introduction of class-based QoS. The old method defined WRED across an entire interface: Router#configure terminal Enter configuration commands, one per line.  End with CNTL/Z. Router(config)#interface HSSI0/0 Router(config-if)#random-detect Router(config-if)#random-detect precedence 0 10 20 10 Router(config-if)#random-detect precedence 1 12 20 10 Router(config-if)#random-detect precedence 2 15 25 15 Router(config-if)#ran..

Exchanging Multicast Routing Information with MBGP

Before setting up MBGP, you should set up multicast-routing on the Autonomous System Boundary Router (ASBR) and configure it to block multicast traffic that you know is only intended for the local network: Router-ASBR1#configure terminal Enter configuration commands, one per line.  End with CNTL/Z. Router-ASBR1(config)#ip multicast-routing Router-ASBR1(config)#access-list 15 deny 239.0.0.0 0.255.255.255 Router-ASBR1(config)#access-list 15 deny 224.0.1.39 Router-AS..