This section describes the different types of interfaces supported by the device. The rest of the chapter describes configuration procedures for physical interface characteristics.

Devices within a single VLAN can communicate directly through any switch. Ports in different VLANs cannot exchange data without going through a routing device. With a standard Layer 2 device, ports in different VLANs have to exchange information through a router. By using the device with routing enabled, when you configure both VLAN 20 and VLAN 30 with an SVI to which an IP address is assigned, packets can be sent from Host A to Host B directly through the device with no need for an external router.

When the Network Advantage license is used on the device or the active device, the device uses the routing method to forward traffic between interfaces. If the Network Essentials license is used on the device or the active device, only basic routing (static routing and RIP) is supported. Whenever possible, to maintain high performance, forwarding is done by the device hardware. However, only IPv4 packets with Ethernet II encapsulation are routed in hardware.

The routing function can be enabled on all SVIs and routed ports. The device routes only IP traffic. When IP routing protocol parameters and address configuration are added to an SVI or routed port, any IP traffic received from these ports is routed.

The device supports these interface types:

• Physical ports: Device ports and routed ports

• VLANs: Switch virtual interfaces

• Port channels: EtherChannel interfaces

You can also configure a range of interfaces. An interface on the device is represented by a 3-tuple notation that lists the module, subslot, and port.

To configure a physical interface (port), specify the interface type, module number, sub-slot number, and device port number, and enter interface configuration mode.

• Type: 10-Gigabit Ethernet (TenGigabitEthernet or te) for 10 Gbps, 25-Gigabit Ethernet (TwentyFiveGigE or twe) for 25 Gbps, 40-Gigabit Ethernet (FortyGigabitEthernet or fo) for 40 Gbps, and 100-Gigabit Ethernet (HundredGigE or hu) for 100Gbps.

• Module number: The module or slot number on the device.

• Subslot number: The subslot number is always 0.

• Port number: The interface number on the device. The port numbering starts with the far left port when facing the front of the device, for example, FortyGigabitEthernet1/0/1.

You can identify physical interfaces by physically checking the interface location on the device. You can also use the show privileged EXEC commands to display information about a specific interface or all the interfaces on the switch. The remainder of this chapter primarily provides physical interface configuration procedures.

Cisco Catalyst 9600 Series Switches support breakout cables. These cables support 4x10 G by enabling a single 40-G QSFP+ interface to be split into four 10-G SFP+ interfaces.

The default port connections depend on whether you use a 40-G QSFP module, a 100-G QSFP28 module, or a breakout cable. You can use a combination of 40-G QSFP modules, 100-G QSFP28 modules, and the 4x10 G breakout cables. Breakout interface naming can be as follows:

• HundredGigabitEthernet slot-num /0/port-num /[1-4]: For a device without Cisco StackWise Virtual (standalone device).

• HundredGigabitEthernet switch-num /slot-num /0/port-num /[1-4]: For a device with Cisco StackWise Virtual.

To configure Layer 2 parameters, if the interface is in Layer 3 mode, you must enter the switchport interface configuration command without any parameters to put the interface into Layer 2 mode. This shuts down the interface and then re-enables it, which might generate messages on the device to which the interface is connected. When you put an interface that is in Layer 3 mode into Layer 2 mode, the previous configuration information related to the affected interface might be lost, and the interface is returned to its default configuration.

Note	The interface is in Layer 2 by default.

This table shows the Ethernet interface default configuration, including some features that apply only to Layer 2 interfaces.

Switch modules include Ethernet (10/100/1000-Mbps) ports. The switch also includes multigigabit ethernet ports which support speeds up to 2.5 Gbps (100/1000/2500-Mbps), 5 Gbps (100/1000/2500/5000-Mbps), 10 Gbps (100/1000/2500/5000/10000-Mbps); SFP modules that support speeds up to 1 Gbps, SFP+ modules that support speeds up to 10 Gbps, SFP28 modules that support speeds up to 25 Gbps, QSFP modules that support speeds up to 40 Gbps and 100 Gbps.

In full-duplex mode, two stations can send and receive traffic at the same time.

When configuring an interface speed and duplex mode, note these guidelines:

• Ethernet ports operating at 10Mbps/100Mbps/1Gbps/2.5Gbps/5/Gbps/10Gbps support full duplex mode. Half duplex mode is not supported.

• If both ends of the line support autonegotiation, we highly recommend the default setting of auto negotiation.

• If one interface supports autonegotiation and the other end does not, configure duplex and speed on both interfaces; do not use the auto setting on the supported side.

• When STP is enabled and a port is reconfigured, the device can take up to 30 seconds to check for loops. The port LED is amber while STP reconfigures. As best practice, we suggest configuring the speed and duplex options on a link to auto or to fixed on both the ends. If one side of the link is configured to auto and the other side is configured to fixed, the link may or may not be up and this is expected.

• Beginning from Cisco IOS XE Cupertino 17.7.1, on Cisco Catalyst 9600 Series Supervisor 2 Module inserted with C9600-LC-48YL and C9600-LC-40YL4CD line cards, the ports in the same port groups must be configured with the same interface speed. You can use the show hw-module slot slot_number port-group command to view port group information of the inserted line cards.

Caution

Changing the interface speed and duplex mode configuration might shut down and re-enable the interface during the reconfiguration.

The Catalyst 9600 modular chassis supports up to four line cards and redundant supervisors. The supervisor has three Unified Access Data Path (UADP 3.0) ASICs connected to each other. Each UADP 3.0 ASIC provides a switching capacity of 1600Gbps full-duplex for the front panel interfaces, resulting in a total capacity of 4800 Gbps full-duplex switching capacity.

Each ASIC also provides a total of 1760 Gbps full-duplex inter-ASIC bandwidth, with 880 Gbps full-duplex to each of the other two ASICs.

The inter-ASIC connections use a broadcast network approach, to ensure that user data is available to all ASICs. In the worst-case scenario, where all traffic is inter-ASIC, the front panel bandwidth can be 2:1 oversubscribed compared to the interface-ASIC bandwidth. Most traffic scenarios (example north-to-south) will only require some traffic to be inter-ASIC.

When a Line card is installed on the chassis, one-third of its ports are connected to each ASIC. Which means, one set of ports on the line card are connected to ASIC 1, the second set to ASIC 2, and the third set of ports are connected to ASIC 3. You can view the port mapping on the line cards using the show platform software fed active ifm mapping command.

By default all the ports on the C9600X-LC-32CD line card are 40G and 100G enabled. When the line card is inserted it comes up in the default mode with all 32 ports operating in the 100G mode. The line card can support up to two ports in the 400G mode. The line card has two port groups of which one port each is able to support the 400G mode. Port group 1 consists of ports 25, 26, 27 and 28. Of these ports, port 27 can support 400G mode. Port group 2 consists of ports 29,30,31 and 32. Of these ports, port 31 can support 400G mode. When the 400G mode is activated in a port group the other three ports of the port group become inactive. These inactive groups will not be visible in the running configuration.

The line card can work in the following three modes:

• Default mode: All 32 ports operate in the default 100G mode.

• One port 400G mode: 28 ports operate in the default 100G mode. One of the ports of the two port groups operates in the 400G mode (either port 27 or port 31).

• Two ports 400G mode: 24 ports operate in the default 100G mode. Both the ports of the two port groups operate in the 400G mode (both port 27 and port 31).

You can enable the 400G mode on the port groups by using the hw-module slot slot-number port-group port-group-number mode 400g command in the global configuration mode. You can enable the 400G mode on both the 400G ports of the two port-groups by using the hw-module slot slot-number port-group range 1-2 mode 400 command.

You can use the no form of the commands to change a port group back to the 100G mode.You can use the show hw-module slot slot-number port-group mode command to display the mode of operation for a port-group.

Note

When a port group is changed from 100G to 400G mode or from 400G to 100G mode all the configurations in the interfaces will revert to default configs. In the 400G mode the configuration is locked on the inactive ports and cannot be modified. Copper ports, Breakout interfaces and the Cisco QSA module are not supported on the C9600X-LC-32CD line card.

The device supports these types of Layer 3 interfaces:

• SVIs: You should configure SVIs for any VLANs for which you want to route traffic. SVIs are created when you enter a VLAN ID following the interface vlan global configuration command. To delete an SVI, use the no interface vlan global configuration command. You cannot delete interface VLAN 1.

  Note	When you create an SVI, it does not become active until it is associated with a physical port. SVI MAC addresses do not change after a device reload. This is expected behavior.

  When configuring SVIs, you can use the switchport autostate exclude command on a port to exclude that port from being included in determining SVI line-state. To disable autostate on the SVI, use the no autostate command on the SVI.

• Routed ports: Routed ports are physical ports configured to be in Layer 3 mode by using the no switchport interface configuration command. A routed port supports VLAN subinterfaces.

  VLAN subinterface: A 802.1Q VLAN subinterface is a virtual Cisco IOS interface that is associated with a VLAN id on a routed physical interface. The parent interface is a physical port. Subinterfaces can be created only on Layer 3 physical interfaces. A subinterface can be associated with different functionalities such as IP addressing, forwarding policies, Quality of Service (QoS) policies, and security policies. Subinterfaces divide the parent interface into two or more virtual interfaces on which you can assign unique Layer 3 parameters such as IP addresses and dynamic routing protocols. The IP address for each subinterface should be in a different subnet from any other subinterface on the parent interface.

• Layer 3 EtherChannel ports: EtherChannel interfaces made up of routed ports.

A Layer 3 device can have an IP address assigned to each routed port and SVI.

You can configure a maximum of 4000 Layer 3 interfaces. If the device is using its maximum hardware resources, attempts to create a routed port or SVI have these results:

• If you try to create a new routed port, the device generates a message that there are not enough resources to convert the interface to a routed port, and the interface remains as a switchport.

• If you try to create an extended-range VLAN, an error message is generated, and the extended-range VLAN is rejected.

• If the device is notified by VLAN Trunking Protocol (VTP) of a new VLAN, it sends a message that there are not enough hardware resources available and shuts down the VLAN. The output of the show vlan user EXEC command shows the VLAN in a suspended state.

• If the device attempts to boot up with a configuration that has more VLANs and routed ports than hardware can support, the VLANs are created, but the routed ports are shut down, and the device sends a message that this was due to insufficient hardware resources.

Note

All Layer 3 interfaces require an IP address to route traffic. This procedure shows how to configure an interface as a Layer 3 interface and how to assign an IP address to an interface: If the physical port is in Layer 2 mode (the default), you must enter the no switchport interface configuration command to put the interface into Layer 3 mode. Entering a no switchport command disables and then re-enables the interface, which might generate messages on the device to which the interface is connected. Furthermore, when you put an interface that is in Layer 2 mode into Layer 3 mode, the previous configuration information related to the affected interface might be lost, and the interface is returned to its default configuration.

The following sections provide information about monitoring interface characteristics.