Specifications

Multilayer Switching Overview
MLS Implementation
3
MLS Implementation
This section provides a step-by-step description of MLS implementation.
Table 37 Summary of Key Features
Feature Description
Ease of Use Is autoconfigurable and autonomously sets up its Layer 3 flow cache. Its “plug-and-play” design
eliminates the need for you to learn new IP switching technologies.
Transparency Requires no end-system changes and no renumbering of subnets. It works with DHCP
1
and requires
no new routing protocols.
1. DHCP = Dynamic Host Configuration Protocol
Standards Based Uses IETF
2
standard routing protocols such as OSPF and RIP for route determination. You can
deploy MLS in a multivendor network.
2. IETF = Internet Engineering Task Force
Investment Protection Provides a simple feature-card upgrade on the Catalyst 5000 series switches. You can use MLS with
your existing chassis and modules. MLS also allows you to use either an integrated RSM or an
external router for route processing and Cisco IOS services.
Fast Convergence Allows you to respond to route failures and routing topology changes by performing
hardware-assisted invalidation of flow entries.
Resilience Provides the benefits of HSRP
3
without additional configuration. This feature enables the switches
to transparently switch over to the Hot Standby backup router when the primary router goes offline,
eliminating a single point of failure in the network.
3. HSRP = Hot Standby Router Protocol
Access Lists Allows you to set up access lists to filter, or to prevent traffic between members of different subnets.
MLS enforces multiple security levels on every packet of the flow at wire speed. It allows you to
configure and enforce access control rules on the RSM. Because MLS parses the packet up to the
transport layer, it enables access lists to be validated. By providing multiple security levels, MLS
enables you to set up rules and control traffic based on IP addresses and transport-layer application
port numbers.
Accounting and
Traffic Management
Allows you to see data flows as they are switched for troubleshooting, traffic management, and
accounting purposes. MLS uses NDE to export the flow statistics. Data collection of flow statistics
is maintained in hardware with no impact on switching performance. The records for expired and
purged flows are grouped and exported to applications such as NetSys for network planning,
RMON2
4
traffic management and monitoring, and accounting applications.
4. RMON2 = Remote Monitoring 2
Network Design
Simplification
Enables you to speed up your network while retaining the existing subnet structure. It makes the
number of Layer 3 hops irrelevant in campus design, enabling you to cope with increases in
any-to-any traffic.
Media Speed Access
to Server Farms
You do not need to centralize servers in multiple VLANs to get direct connections. By providing
security on a per-flow basis, you can control access to the servers and filter traffic based on subnet
numbers and transport-layer application ports without compromising Layer 3 switching
performance.
Faster Interworkgroup
Connectivity
Addresses the need for higher-performance interworkgroup connectivity by intranet and multimedia
applications. By deploying MLS, you gain the benefits of both switching and routing on the same
platform.