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This chapter describes and lists the hardware and software features and functionality of the Multilayer Switch Feature Card (MSFC) and the Policy Feature Card (PFC) for the Catalyst 6000 family switches.
The MSFC provides multiprotocol routing with up to 15 million packets per second (Mpps) of multilayer switching (MLS) (Layer 3 switching) for the Catalyst 6000 family switch Ethernet interfaces. MLS is supported for IP, IP Multicast, and Internetwork Packet Exchange (IPX) protocols.
The PFC maintains a Layer 3 switching table (the Layer 3 MLS cache) for Layer 3-switched flows. The cache also includes entries for traffic statistics that are updated in tandem with the switching of packets. After the MLS cache is created, packets identified as belonging to an existing flow can be Layer 3-switched based on the cached information. The MLS cache maintains flow information for all active flows.
This chapter contains these sections:
Table 1-1 lists the Cisco IOS features available for the MSFC.
| Layer 3 Forwarding Features |
Wire speed IP, IP multicast, and IPX routing between VLANs |
Support for up to 128K entries for IP network prefixes, IP unicast and multicast addresses, IPX network numbers, and MAC addresses1 |
FIB2 and adjacency database support as defined in other Cisco routers |
Destination-based load sharing among equal cost paths |
| Layer 3 Routing Protocols |
Static IP routing |
IP multicast routing protocols: PIM7 (sparse and dense mode) and DVMRP8 interrupt |
IPX routing protocols: RIP, NLSP9, and EIGRP |
| Layer 3 Related Protocols |
IGMP10 v1 and v2 |
IGMP snooping |
CGMP11 server support |
Full ICMP12 support |
GDP13 |
IRDP14 |
MSDP15 |
MBGP16 |
| Enhanced Services |
Standard DNS17 support |
M-HSRP20 |
CDP21 |
Wire-speed IP standard ACL support |
Standard reflexive ACL |
| Layer 3 QoS22 Related Features |
Two priority queues for CoS23-based operation |
IP precedence-based IP forwarding |
These sections provide an overview of MLS requirements:
The software requirements are as follows:
Two MSFC images are provided on the MSFC bootflash: a boot helper image and a system image. The boot helper image is a limited function system image that has network interface code and end-host protocol code. The system image is the main Cisco IOS software image with full multiprotocol routing support.
 | Caution The boot helper image must not be erased and must always remain as the first image on the MSFC bootflash as it is always used as the first image to boot. |
The hardware requirements are as follows:
The required components for MLS are as follows:
MLS, or Layer 3 switching, integrates routing with switching to yield very high routing throughput. To provide MLS, the MSFC, which resides on the supervisor engine, runs Cisco IOS router software to communicate with the rest of the logic on the supervisor engine via the Interprocessor Communication (IPC) bus.
Figure 1-1 shows the layout of the system with the MSFC added to the existing supervior engine. The MSFC contains the MLS application-specific integrated circuits (ASICs) and an MLS route processor that calculates the routes and associated forwarding information base (FIB) tables.
The first packet in a given flow goes to the route processor and is forwarded to the destination using traditional routing methods. At this point, the supervisor engine learns all the information it needs to forward the subsequent packets on its own in hardware and bypasses the route processor. The supervisor engine performs all the Layer 3 rewrites, and the receiving device thinks it is getting the packets from the router.
VLAN 1 and additional VLANs are assigned the base MAC address from a MAC address PROM on the MSFC. The PROM contains up to 1024 MAC addresses. All routing interfaces use the base MAC address. You can override the base MAC address and use one of the other block addresses by entering the mac-address interface configuration command. The other block addresses are determined as follows: base MAC address + 1, base MAC address + 2, and so on. Note that there is normally no need to override the default MAC address.
You can configure Hot Standby Routing Protocol (HSRP) on the MSFCs to provide automatic routing backup for your network. HSRP is compatible with IPX and AppleTalk. HSRP allows one MSFC (router) to assume the function automatically of the second MSFC if the second MSFC fails.
To use HSRP, you must have one of the following configurations:
These sections provide an overview of power management:
If you have two power supplies of equal wattage installed, you can configure them in a redundant configuration. Use the set power redundancy enable | disable command to enable or disable redundancy. In a redundant configuration, the total power drawn from both supplies is at no time greater than the capability of one supply. If one supply malfunctions, the other supply can take over the entire system load. When you install and turn on two power supplies, each concurrently provides approximately half of the required power to the system. Load sharing and redundancy are enabled automatically; no software configuration is required.
In a nonredundant configuration, the power available to the system is the combined power capability of both power supplies. The system powers up as many modules as the combined capacity allows.
For more information on power management, refer to the Catalyst 6000 Family Module Installation Guide.
Environmental monitoring of chassis components provides early warning indications of possible component failure to ensure safe and reliable system operation and avoid network interruptions. For detailed information on environmental monitoring, refer to the Catalyst 6000 Family Module Installation Guide.
Posted: Tue Dec 7 10:49:44 PST 1999
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