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MLS Statistics on Cat6500 w/ Sup720

Dirk Woellhaf


when using "show mls statistics" I see a lot packets are getting L3 Processed. Does that mean they are getting software-forwarded?

IOS is 12.2(33)SXI5.

Cat6k#show mls statistics

Statistics for Earl in Module 5

L2 Forwarding Engine

  Total packets Switched                : 46828375556247

L3 Forwarding Engine

  Total packets Processed               : 23360284229069 @ 1132343 pps

  Total packets L3 Switched             : 12958356175277 @ 599776 pps



(Please rate if helpful)       

regards, Dirk (Please rate if helpful)
1 Reply 1

Reza Sharifi
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No, just because is layer-3 switched, it doesn't necessary mean software forwarding.

Policy Feature Card

Complementing  the MSFC is the policy feature card (PFC). The PFC is a daughter card  that sits on the supervisor base board and contains the ASICs that are  used to accelerate Layer 2 and Layer 3 switching, store and process QoS  and security ACLs, and maintain NetFlow statistics.

The Policy Feature Card 3 (PFC3)  is a standard inclusion with the Supervisor Engine 720 and provides  centralized forwarding performance up to 30Mpps. It contains a Layer 2  and a Layer 3 forwarding engine. The Layer 2 engine is responsible for:

• Layer 2 MAC address lookups into the Layer 2 CAM table.

•  Looking into the packet headers to determine if this switching  operation will be a Layer 2 or a Layer 3 operation. If it is going to be  a Layer 3 operation, then it will hand off the packet to the Layer 3  engine for further processing.

The Layer 3 Engine is responsible for:

• NetFlow Statistics collection.

• Hardware based forwarding of IPv4, IPv6 and MPLS tagged packets

• QoS mechanism for ACL classification, marking of packets, and policing (rate limiting).

• Security mechanism for validating ACL rules against incoming packets.

• Maintaining Adjacency entries and statistics

• Maintaining Security ACL counters

The  PFC3 (Figure 7) supports hardware based Layer 2 and Layer 3 switching,  processing security and QoS ACLs in hardware and the collection of  NetFlow statistics.
here is the link to the doc:
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