Single-Homing Scenario: Addresses Taken from Outside the Provider's Address Space

The routing rules discussed so far, along with the nature of a network's address space and whether it is single-homed or multihomed, have implications for whether and how the network can aggregate addresses. This section and the next three sections examine several scenarios. In the single-homing scenario, the customer is connected to a single provider and has IP address space totally different from the provider's. This could have occurred because the customer changed provider..

Groups of AAA Servers

By default, Cisco IOS automatically groups RADIUS and TACACS+ servers configured with the radius-server host and tacacs-server host commands into groups, aptly named radius and tacacs+. The aaa authentication command includes the keywords group radius or group tacacs+ to refer to these default groups. By default, all defined RADIUS servers end up in the radius group, and all defined TACACS+ servers end up in the tacacs+ group. In some cases, particularly with larger-scale dia..

WFQ Drop Policy, Number of Queues, and Queue Lengths

WFQ uses a two-step process called modified tail drop to choose when to drop packets. First, WFQ considers the absolute limit on the number of packets enqueued among all queues; this limit is called the hold-queue limit. If a new packet arrives, and the hold-queue limit has been reached, the packet is discarded. That part of the decision is based not on a single queue, but on the whole WFQ queuing system for the interface. Second, WFQ considers the length of the queue into w..

WAN Edge Classification and Provisioning Models

One of the most common questions raised when planning a QoS deployment over the WAN is "How many classes of traffic should be provisioned for?" The following considerations should be kept in mind when arriving at an appropriate traffic class model for a given enterprise. Slow/Medium Link-Speed QoS Class Models Slow-speed (  768 kbps) links have very little bandwidth to carve up, to begin with. When the serialization implications of sending Interactive-Video into the LL..

Monitoring and Troubleshooting RSVP Support for Frame Relay

Example 22-4 shows the configuration commands needed to add on routers R1 and R2 for this purpose. Example 22-4. Using ip rsvp sender-host and ip rsvp reservation-host to Routers R1 and R2 ! Router R1 R1(config)# ip rsvp sender-host 20.0.0.2 10.0.0.1 udp 7000 7001 16 1 ! Router R2 R2(config)# ip rsvp reservation-host 20.0.0.2 10.0.0.1 UDP 7000 7001 FF LOAD 16 1 The ip rsvp sender-host command causes router R1 to simulate an IP RSVP sender-host located at 10.0.0.1, which ..