There are several factors influencing the changes contained in this second edition. The first factor is the CCIE itself. When I (Jeff) wrote the first edition of this book, the CCIEspecifically what is now called the Routing and Switching specialty of the CCIEwas the only certification Cisco Systems offered. Now, there is a series of [...]
Classification establishes an internal DSCP value, which the switches use to differentiate packets during packet processing, policing, and output scheduling and queuing. The Catalyst 2950 Family of switches supports the following classification options:
Ingress port CoS configuration
Trust CoS
Trust DSCP
Extended trust on voice and VLANs
ACL-based classification
Classified model based on internal DSCP
CoS and DSCP mapping tables
The Catalyst 3550 [...]
When matching on multiple characteristics, two options exist for creating the class map: match-any and match-all, as demonstrated in Example 5-1.
Example 5-1. Class Map Options
R1(config) class-map ?
WORD class-map name
match-all Logical-AND all matching statements under this classmap
match-any Logical-OR all matching statements under this classmap
The match-any option is a logical OR operation, in which only one of [...]
The Catalyst 5000 Family of switches supports QoS with only specific Supervisors and line modules. These switches support QoS features limited to classification of untagged frames, marking based on ACEs, and output scheduling. These features classify frames solely on ccie security values. For most applications, DSCP classification is desirable. As a result, network designs should [...]
Similar to other access layer switches, the Catalyst 4000 CatOS switches performs only FIFO Queuing of ingress packets. For line-module ports that are nonblocking, FIFO Queuing does not pose an issue because nonblocking line-module ports can deliver traffic to the switching fabric at line rate. Ports that are oversubscribed to the switching fabric are also [...]
The Catalyst 2950 Family of switches runs two feature sets of Cisco IOS, a standard image (SI) and an enhanced image (EI). Several feature differences exist between the SI and EI versions.
The SI version only supports 64 VLANs, for instance, whereas the EI version supports 256 VLANs with ACL support on physical interfaces. The SI [...]