Cisco Catalyst 2960-X Command Reference

When you enter trunk mode, the interface changes to permanent trunking mode and negotiates to convert
the link into a trunk link even if the interface connecting to it does not agree to the change.
When you enter dynamic auto mode, the interface converts the link to a trunk link if the neighboring interface
is set to trunk or desirable mode.
When you enter dynamic desirable mode, the interface becomes a trunk interface if the neighboring interface
is set to trunk, desirable, or auto mode.
To autonegotiate trunking, the interfaces must be in the same VLAN Trunking Protocol (VTP) domain. Trunk
negotiation is managed by the Dynamic Trunking Protocol (DTP), which is a point-to-point protocol. However,
some internetworking devices might forward DTP frames improperly, which could cause misconfigurations.
To avoid this problem, configure interfaces connected to devices that do not support DTP to not forward DTP
frames, which turns off DTP.
•
If you do not intend to trunk across those links, use the switchport mode access interface configuration
command to disable trunking.
•
To enable trunking to a device that does not support DTP, use the switchport mode trunk and switchport
nonegotiate interface configuration commands to cause the interface to become a trunk but to not
generate DTP frames.
Access ports and trunk ports are mutually exclusive.
The IEEE 802.1x feature interacts with switchport modes in these ways:
•
If you try to enable IEEE 802.1x on a trunk port, an error message appears, and IEEE 802.1x is not
enabled. If you try to change the mode of an IEEE 802.1x-enabled port to trunk, the port mode is not
changed.
•
If you try to enable IEEE 802.1x on a port set to dynamic auto or dynamic desirable, an error message
appears, and IEEE 802.1x is not enabled. If you try to change the mode of an IEEE 802.1x-enabled port
to dynamic auto or dynamic desirable, the port mode is not changed.
•
If you try to enable IEEE 802.1x on a dynamic-access (VLAN Query Protocol [VQP]) port, an error
message appears, and IEEE 802.1x is not enabled. If you try to change an IEEE 802.1x-enabled port to
dynamic VLAN assignment, an error message appears, and the VLAN configuration is not changed.
You can verify your settings by entering the show interfaces interface-id switchport privileged EXEC
command and examining information in the Administrative Mode and Operational Mode rows.
Examples
This example shows how to configure a port for access mode:
Switch(config)# interface gigabitethernet2/0/1
Switch(config-if)# switchport mode access
This example shows how set the port to dynamic desirable mode:
Switch(config)# interface gigabitethernet2/0/1
Switch(config-if)# switchport mode dynamic desirable
This example shows how to configure a port for trunk mode:
Switch(config)# interface gigabitethernet2/0/1
Switch(config-if)# switchport mode trunk
Catalyst 2960-X Switch Layer 2 Command Reference, Cisco IOS Release 15.0(2)EX
OL-29043 -01 117
Layer 2 Commands
switchport mode

Cisco Catalyst 2960-X Specifications

General

Console port	RJ-45
USB 2.0 ports quantity	2
SFP module slots quantity	4
Installed SFP modules quantity	-
Gigabit Ethernet (copper) ports quantity	48
Basic switching RJ-45 Ethernet ports type	Gigabit Ethernet (10/100/1000)
Power source	AC
Input current	5 A
AC input voltage	100 - 240 V
Power consumption (typical)	60.9 W
Number of power supply units	1
Redundant power supply (RPS) support	Yes
Operating altitude	0 - 3000 m
Non-operating altitude	0 - 4000 m
Storage temperature (T-T)	-25 - 70 °C
Operating temperature (T-T)	-5 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Switching protocols	UDP, TCP, RADIUS/TACACS+
Number of VLANs	1023
Networking standards	IEEE 802.1ab, IEEE 802.1D, IEEE 802.1p, IEEE 802.1Q, IEEE 802.1s, IEEE 802.1w, IEEE 802.1x, IEEE 802.3, IEEE 802.3ab, IEEE 802.3ad, IEEE 802.3ae, IEEE 802.3af, IEEE 802.3ah, IEEE 802.3at, IEEE 802.3az, IEEE 802.3u, IEEE 802.3x, IEEE 802.3z
Throughput	107.1 Mpps
Jumbo frames	9216
Number of queues	8
MAC address table	16000 entries
Number of static routes	1000
DHCP features	DHCP server
Authentication	MAC-based authentication, Port-based authentication
Security algorithms	802.1x RADIUS, SNMP, SSH
Access Control List (ACL) rules	3
Switch type	Managed
Switch layer	L2/L3
Safety	UL 60950-1, CAN/CSA-C22.2 No. 60950-1, EN 60950-1, IEC 60950-1, AS/NZS 60950-1
Form factor	1U
Product color	Black
Total Power over Ethernet (PoE) budget	370 W
Power over Ethernet (PoE) ports quantity	24
Power over Ethernet plus (PoE+) ports quantity	12
Memory type	DRAM
Noise level	39 dB
Flash memory	128 MB
Internal memory	512 MB
Processor frequency	600 MHz
Mean time between failures (MTBF)	276870 h

Weight and Dimensions

Depth	368 mm
Width	445 mm
Height	45 mm
Weight	5800 g