Specifications

CHAPTER 4
InterVLAN Routing
n Separates control plane hardware from data plane hardware.
n Controls plane runs in software and builds FIB and adjacency table.
n The data plane uses hardware to forward most IP unicast traffic.
n Uses TCAM table.
n Can be centralized or distributed.
Not all types of traffic can be handled by CEF. Some types that are punted (sent to the processor for handling) are:
n Packets with IP header options
n Tunneled traffic
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CCNP SWITCH 642-813 Quick Reference by Denise Donohue
FIGURE 4-1
Cisco Express
Forwarding
BGP Table
Address Prefix AS-Path Communities Other Attr.Next-Hop
10.0.0.0 /8 42 13 37:121.2.3.4
... ... ... ... ......
IP Routing
Table
Address Prefix
... ...
FIB Table
(CEF Cache)
Next-Hop Outgoing InterfaceAddressProtocol
BGP
ARP Cache
Adjacency Pointer
...
1.5.4.1 Ethernet 01.2.3.0OSPF
MAC Address
...
IP Address
...
Layer 2 Header
...
Adjacency
Table
IP Address
...
1.5.4.1 MAC Header
Prefix
/24
Precedence
—
QoS Group
—
—
1.2.3.4 —10.0.0.0 /8 3 7
BGP Table Map
Precedence
...
QoS Group
...
0c.00.11.22.33.441.5.4.1
10.0.0.0 /8 1.5.4.1 3 7
Conn.
1.5.4.0 /24
—
Ethernet 0
—