The BGP AS_PATH and AS_PATH Segment Types

RFC 1771 describes four types of AS_PATH segments held inside the AS_PATH PA (see Table 13-3). The most common segment is called AS_SEQUENCE, which is an ordered list of all the autonomous systems through which the route has passed. The AS_SEQUENCE segment lists the most recently added ASN as the first ASN; this value is also the leftmost entry when looking at show commands, and is considered to be the first ASN for the regex matching logic. Because the most recently added AS..

Finding Subnet Numbers and Valid Range of IP Addresses—Binary

When examining an IP address and mask, the process of finding the subnet number, the broadcast address, and the range of valid IP addresses is as fundamental to networking as is addition and subtraction for advanced math. Possibly more so for the CCIE Routing and Switching lab exam, mastery of the math behind subnetting, which is the same basic math behind route summarization and filtering, will improve your speed completing complex configurations on the exam. The range of v..

Deploying GR and Fast Convergence Technologies

Up to this point, the chapter has covered the difficulty of fast convergence, the fast polling and event-driven mechanisms for fast convergence, graceful restart, and routing protocol modifications and considerations for fast convergence. With all of this as background, how do you actually deploy these technologies and techniques to provide a fast, stable network? Graceful Restart Versus Fast Down Detection Examining all these techniques, only fast down detection and GR app..

Data Structures of EIGRP

Now that you have reviewed, from a generic perspective, how an IP routing protocol’s data structure interacts with a router’s IP routing table, consider the specific data structures used by EIGRP, as described in Table 6-4.

LLQ, or PQ/CBWFQ

With the emergence of voice traffic into data networks, the need to differentiate between the various classes of service has become greater. PQ/CBWFQ, most commonly known as LLQ, is a new feature that provides a strict priority queue for voice traffic and a weighted fair queue for each of the other classes of traffic. LLQ brings strict priority queuing to the CBWFQ scheme. Figure 18-4 illustrates the basic concepts of how LLQ works. Figure 18-4. How LLQ Works   Without ..