Ethernet types

Technology Wiring Type Cable length
100BASE-TX EIA/TIA Cat 5 UTP 100 m
100BASE-T2 EIA/TIA Cat 3, 4, 5 UTP 100 m
100BASE-T4 EIA/TIA Cat 3, 4, 5 UTP 100 m
100BASE-FX Multimode fiber (MMF); 62.5 micron core, 125-micron outer cladding (62.5/125) 400 m half
2 km full
1000BASE-CX Shielded twisted pair (STP) 25 m
1000BASE-T EIA/TIA Cat 5 UTP  100 m
1000BASE-SX MMF: 62.5-micron core; 850-nm laser
MMF: 50-micron core; 850-nm laser
275 m
550 m
1000BASE-LX/LH MMF: 62.5-micron core; 1300-nm laser
MMF: 50-micron core; 1300-nm laser
SMF: 9-micron core; 1300-nm laser
550 m
550 m
10 km
1000BASE-ZX SMF: 9-micron core; 1550-nm laser
SMF: 8-micron core; 1550-nm laser
70 km
100 km
10GBASE-SR/SW  (850 nm) MMF: 50 micron
MMF: 50 micron (2GHz* km modal bandwith)
MMF: 62.5 micron
10GBASE-LR/LW (1310 nm) SMF: 9 micron 10 km
10GBASE-ER/EW (1550 nm) SMF: 9 micron 40 km
10GBASE-LX4/LW4 (1310 nm) MMF: 50 micron
MMF: 62.5 mircon
SMF: 9 mircron
300 m
300 m
10 km
10GBASE-CX4 Copper: CX4 with Infiniband connectors 15 m


Type Connector
1000BASE-SX SC fiber
100BASE-LX/LH SC fiber with MMF or SMF
MMF requires a special mode-conditioning cable for fiber distances less than 100 m
(328 feet) or greater than 300 m (984 feet). This keeps the GBIC from overdriving the
far-end receiver on a short cable and lessens the effect of differential mode delay on
a long cable.
1000BASE-ZX SC fiber connectors + SMF
1000BASE-T RJ-45 connector
10GBASE-CX4 Copper
10GBASE-SR Short-reach MMF
10GBASE-LRM Long-reach MMF
10GBASE-LR Long-reach SMF
10GBASE-ER Extended-reach SMF




Understanding MSFC, PFC and DFC


Useful info about Supervision Engine 720 in Cisco 6500/7600


Multilayer Switch Feature Card in nutshell

Multilayer Switch Feature Card is the Layer 3 switching engine that sites on the Catalyst Supervisor as a daughter card.

The MSFC builds the Cisco Express Forwarding information Base (FIB) table in software and then downloads this table to the hardware Application-specific-integrated circuits (ASICs) on the PFC and DFC (if present) that make the forwarding decisions for IP unicast and multicast traffic.

Role of Multilayer Switch Feature Card (MSFC)

  1. Provide IOS based multi-protocol routing using a variety of routing protocols.
  2. Work with the PFC for implementing layer 3 switching & traditional router based input/output ACL’s. Note, PFC can implement ACL’s without requiring a MSFC.
  3. Provide other SW based features (like NAT, Policy Routing, Encryption etc) which are not supported in PFC hardware.

Policy Feature Card (PFC) in nutshell

The PFC3 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.

Role of Policy Feature Card (PFC) Layer 2 engine

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

Role of Policy Feature Card (PFC) Layer 3 Engine

  1. NetFlow Statistics collection.
  2. Hardware based forwarding of IPv4, IPv6 and MPLS tagged packets.
  3. QoS mechanism for ACL classification, marking of packets, and policing (rate limiting).
  4. Security mechanism for validating ACL rules against incoming packets.
  5. Maintaining Adjacency entries and statistics.
  6. Maintaining Security ACL counters.


Distributed Forwarding Card (DFC) in nutshell

Distributed Forwarding Card is a combo daughter card comprising a MSFC and PFC used by a fabric enabled Cat6500 linecard to perform distributed switching. DFCs are located in linecards, not in Supervisors.


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