Multihoming Scenario: Addresses Taken from Different Providers
One possibility for large domains is to take IP addresses from different providers based on geographic location. Consider Figure 3-16. Largenet has taken its IP addresses from two different providers, ISP1 and ISP2. With this design, each provider will be able to aggregate its own address space without having to list specific ranges from the other provider. ISP1 would advertise the aggregate 198.24.0.0/13, and ISP2 would advertise the aggregate 198.32.0.0/13. Both aggregates ..
OSPF provides two levels of hierarchy throughout an area. An area is a 32-bit number that can be defined either in an IP address format of "Area 0.0.0.0" or as a decimal number format, such as "Area 0." Area 0 is a backbone area, which is required if more than one area is configured. All areas must be connected to Area 0; otherwise, virtual links are needed, as shown in Figure 8-18. Figure 8-18. Using a Virtual Link Where an Area Is Not Attached to the Backbone Example 8-..
The first approach utilizes a single CPU-controlled shared bus that connects a number of slave interface cards. This arrangement can be based on a general-purpose computer, such as a PC running UNIX or Windows NT. Various bus communication strategies (such as shared memory, DMA, and bus mastering), together with high-performance RISC CPUs, can result in a router of significant forwarding capabilities. A large number of dedicated-purpose centralized CPU router pl..
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..
Using DLSw to Bridge Between Ethernet and Token Ring
DLSw includes the capability to bridge different kinds of media. One common example of this is bridging an Ethernet segment to a Token Ring. dlsw-ether-branch#configure terminal Enter configuration commands, one per line. End with CNTL/Z. dlsw-ether-branch(config)#interface Loopback0 dlsw-ether-branch(config-if)#ip address 10.1.3.5 255.255.255.252 dlsw-ether-branch(config-if)#exit dlsw-ether-branch(config)#access-list 200 permit 0x0000 0x0D0D dlsw-ether-branch(config)#..
