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Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
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Chapter 17 Configuring IP Unicast Layer 3 Switching on Supervisor Engine 2
Default Hardware Layer 3 Switching Configuration
Default Hardware Layer 3 Switching Configuration
Table 17-1 shows the default hardware Layer 3 switching configuration.
Layer 3 Switching Configuration Guidelines and Restrictions
Follow these guidelines and restrictions when configuring hardware Layer 3 switching:
The PFC2 supports a maximum of 16 unique Hot Standby Routing Protocol (HSRP) group numbers.
You can use the same HSRP group numbers in different VLANs. If you configure more than 16 HSRP
groups, this restriction prevents use of the VLAN number as the HSRP group number.
Note Identically numbered HSRP groups use the same virtual MAC address, which might cause
errors if you configure bridge groups.
Hardware Layer 3 switching supports the following ingress and egress encapsulations:
Ethernet V2.0 (ARPA)
802.3 with 802.2 with 1 byte control (SAP1)
802.3 with 802.2 and SNAP
Note With Release 12.1(11b)E and later, when you are in configuration mode you can enter EXEC mode-level
commands by entering the do keyword before the EXEC mode-level command.
Table 17-1 Default Hardware Layer 3 Switching Configuration
Feature Default Value
Hardware Layer 3 switching enable state Enabled (cannot be disabled)
Cisco IOS CEF enable state on MSFC2 Enabled (cannot be disabled)
Cisco IOS dCEF1 enable state on MSFC2
1. dCEF = Distributed Cisco Express Forwarding
Enabled (cannot be disabled)
IGMP2 snooping
2. IGMP = Internet Group Management Protocol
Enabled
Multicast routing on MSFC2 Disabled globally
PIM3 routing on MSFC2
3. PIM = Protocol Independent Multicast
Disabled on all Layer 3 interfaces
IP multicast Layer 3 switching threshold Unconfigured—no default value
IP multicast Layer 3 switching Enabled when multicast routing is enabled and IP
PIM is enabled on the interface