Reference Guide

Interfaces | 415
For more information on VLANs, refer to Bulk Configuration and for more information on port channels,
refer to Port Channel Interfaces.
Configuration Task List for Physical Interfaces
By default, all interfaces are operationally disabled and traffic will not pass through them.
The following section includes information about optional configurations for physical interfaces:
• Overview of Layer Modes
• Configure Layer 2 (Data Link) Mode
• Management Interfaces
• Auto-Negotiation on Ethernet Interfaces
• Adjust the keepalive timer
• Clear interface counters
Overview of Layer Modes
On all systems running FTOS, you can place physical interfaces, port channels, and VLANs in Layer 2
mode or Layer 3 mode.
By default, VLANs are in Layer 2 mode.
FTOS Behavior: S-Series systems use a single MAC address for all physical interfaces while
E-Series and C-Series use a unique MAC address for each physical interface, though this results in no
functional difference between these platforms.
Table 23-1. Interfaces Types
Type of Interface
Possible
Modes Requires Creation Default State
10/100/1000 Ethernet, Gigabit
Ethernet, 10 Gigabit Ethernet
Layer 2
Layer 3
No Shutdown (disabled)
SONET (PPP encapsulation) Layer 3 No Shutdown (disabled)
Management n/a No Shutdown (disabled)
Loopback Layer 3 Yes No shutdown (enabled)
Null interface n/a No Enabled
Port Channel Layer 2
Layer 3
Yes Shutdown (disabled)
VLAN Layer 2
Layer 3
Yes, except for the default VLAN No shutdown (active for Layer 2)
Shutdown (disabled for Layer 3)