Locations for Marking and Matching
Figure 14-3 shows a sample network, with notes about the locations of the QoS fields. Figure 14-3 Sample Network Showing Non-IP Markable QoS Fields In such a network, the IPP and DSCP inside the IP packet remain intact from end to end. However, some devices may not be able to look at the IPP or DSCP fields, and some may find it more convenient to look at some other header field. For instance, an MPLS Label Switch Router (LSR) inside the MPLS cloud may be configured ..
This section discusses MPLS operation over interfaces where labeled packets are sent encapsulated in Layer 2 frames (Frame-mode MPLS operation). Label Switch Routers (LSRs) use Label Distribution Protocol (LDP, an IETF standard) or Tag Distribution Protocol (TDP, a Cisco pre-standard) to exchange IP prefix-to-label bindings. A Label Information Base (LIB, also called a Tag Information Base [TIB]) stores these bindings, which are used to build the Forwarding Information Base ..
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..
Cisco Router and Security Device Manager
Cisco Router and Security Device Manager (SDM) is an intuitive, secure, web-based embedded device manager of Cisco IOSenabled devices. SDM provides intelligent wizards, detects mis-configured devices, steps security managers through firewall and VPN configurations, and has been certified and recommended by some key organizations within Cisco, such as the Cisco Network Supported Accounts (NSA), a group of expert engineers within Cisco whose services are sold to high-end client..
Recall that the traditional STP offers the PortFast feature, in which switch ports are allowed to immediately enter the Forwarding state as soon as the link comes up. Normally, PortFast provides quick network access to end-user devices, where bridging loops never are expected to form. Even while PortFast is enabled on a port, STP still is running and can detect a bridging loop. However, a loop can be detected only in a finite amount of time— the length of time require..
