Although hosting has been around almost as long as dedicated access services, it has become very popular over the past few years, with many service providers specializing in this market. Large providers that focus on dedicated hosting are commonly referred to as content providers. These providers usually develop highly fault-tolerant data center facilities that house cabinets or racks in which both enterprise and Web hosting customers can lease space and collocate servers and..
CAR and WRED provide QoS policy enforcement within the router, but how is this policy propagated throughout the network? BGP policy propagation makes this possible by enabling you to adjust the IP precedence of a packet based on its source or destination address and, optionally, based on the associated BGP community and/or as-path. Recall from Chapter 11, "Border Gateway Protocol," that an as-path is a mandatory BGP attribute that lists each autonomous system through wh..
DoS/Worm-Mitigation Strategies
A proactive approach to mitigating DoS/worm flooding attacks within campus environments is to respond immediately to out-of-profile network behavior that indicates a DoS or worm attack using access-layer policers. Such policers could meter traffic rates received from endpoint devices, and when these exceed specified watermarks (at which point they no longer are considered normal flows), these policers could mark down excess traffic. In this respect, the policers would be fai..
RSVP is a per-flow protocol that requests a bandwidth reservation from every node in the path of the flow. In its simplest form, RSVP is a unidirectional protocol, so if a bidirectional reservation is required for a flow, both endpoints must initiate a request for a reservation. Basic RSVP protocol operation is shown in Figure 8-1 and its configuration in Example 8-1. The endpoints, or other network devices on behalf of the endpoints, send unicast signaling messages to estab..
Setting Up Frame Relay with Point-to-Point Subinterfaces
Probably the cleanest way to set up a Frame Relay network is to use point-to-point subinterfaces. If you have a host site that connects to two or more branches through a Frame Relay WAN, you could configure the central host router like this: Central#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Central(config)#interface Serial0 Central(config-if)#description Frame-Relay host circuit Central(config-if)#no ip address Central(config-if)#e..
