SM interface ports begin numbering with “0” from left to right. Single-port SMs use only the port number 0. To configure or monitor SM interfaces, you need to specify the physical location of the SM, and interface in the CLI. The interface address format is slot/subslot/port, where:

• slot —Specifies the chassis slot number in the Cisco ISR 4400 series routers where the SIP is installed.
• subslot —Specifies the slot of the SIP where the SM is installed.
• port —Specifies the number of the individual interface port on a SM.

The following example shows how to specify the first interface (0) on a SM installed in the first subslot of a SIP (0) installed in chassis slot 1:

router(config)# interface GigabitEthernet 1/0/0

interface GigabitEthernet1/0/0
no ip address
shutdown
negotiation auto
no cdp enable

The Cisco SM-X-6X1G and Cisco SM-X-4X1G-1X10G use a default MAC address for each port that is derived from the base address that is stored in the electrically erasable programmable read-only memory (EEPROM) on the backplane of the Cisco ISR 4400 series routers.

To modify the default MAC address of an interface to some user-defined address, use the following command in interface configuration mode:

The Hot Standby Router Protocol (HSRP) provides high network availability because it routes IP traffic from hosts without relying on the availability of any single router. HSRP is used in a group of routers for selecting an active router and a standby router. (An active router is the router of choice for routing packets; a standby router is a router that takes over the routing duties when an active router fails, or when preset conditions are met).

HSRP is enabled on an interface by entering the standby [group-number]ip [ip-address[secondary]] command. The standby command is also used to configure various HSRP elements. This document does not discuss more complex HSRP configurations. For additional information on configuring HSRP, refer to the HSRP section of the Cisco IP Configuration Guide publication that corresponds to your Cisco IOS XE software release. In the following HSRP configuration, standby group 2 on Gigabit Ethernet port 2/0/0 is configured at a priority of 110 and is also configured to have a preemptive delay should a switchover to this port occur:

Router(config)# interface GigabitEthernet 2/0/0
Router(config-if)# standby 2 ip 120.12.1.200
Router(config-if)# standby 2 priority 110
Router(config-if)# standby 2 preempt

The Cisco IOS software supports three different types of configurable maximum transmission unit (MTU) options at different levels of the protocol stack:

• Interface MTU—Checked by the SM on traffic coming in from the network. Different interface types support different interface MTU sizes and defaults. The interface MTU defines the maximum packet size allowable (in bytes) for an interface before drops occur. If the frame is smaller than the interface MTU size, but is not smaller than the minimum frame size for the interface type (such as 64 bytes for Ethernet), then the frame continues to process.
• IP MTU—Can be configured on an interface or subinterface. If an IP packet exceeds the IP MTU size, then the packet is fragmented.
• Tag or Multiprotocol Label Switching (MPLS) MTU—Can be configured on an interface or subinterface and allows up to six different labels, or tag headers, to be attached to a packet. The maximum number of labels is dependent on your Cisco IOS software release.

Different encapsulation methods and the number of MPLS MTU labels add additional overhead to a packet. For example, Subnetwork Access Protocol (SNAP) encapsulation adds an 8-byte header, dot1q encapsulation adds a 2-byte header, and each MPLS label adds a 4-byte header (n labels x 4 bytes).

For Cisco SM-X-6X1G and Cisco SM-X-4X1G-1X10G on the Cisco ISR 4400 series routers, the default MTU size is 1500 bytes. The maximum configurable MTU is 9216 bytes. The SM automatically adds an additional 22 bytes to the configured MTU size to accommodate some of the additional overhead.

Note	In the Cisco ISR 4400 series routers, 2RU and 2RU-Fixed chassis, the MTU size for the Management Ethernet interface (interface gigabitethernet 0) is limited to 4470 bytes.

The SM-X-6X1G and SM-X-4X1G-1X10G module support two priority queues per port on ingress. The high-priority queue is always processed before the low-priority queue.

By default, the interfaces on the Cisco SM-X-6X1G and Cisco SM-X-4X1G-1X10G support Advanced Research Projects Agency (ARPA) encapsulation. They do not support configuration of service access point or SNAP encapsulation for transmission of frames.

The only other encapsulation supported by the SM interfaces is IEEE 802.1Q encapsulation for virtual LANs (VLANs).

The Gigabit Ethernet interfaces use a connection-setup algorithm called autonegotiation. Autonegotiation allows the local and remote devices to configure compatible settings for communication over the link. Using autonegotiation, each device advertises its transmission capabilities and then agrees upon the settings to be used for the link.

For the Gigabit Ethernet interfaces on Cisco ISR 4400 series routers, flow control is autonegotiated when autonegotiation is enabled. Autonegotiation is enabled by default.

The following guidelines should be followed regarding autonegotiation:

• If autonegotiation is disabled on one end of a link, it must be disabled on the other end of the link. If one end of a link has autonegotiation disabled while the other end of the link does not, the link will not come up properly on both ends.
• Autonegotiation is not supported on the 10GE ports in the SM-X-4X1G-1X10G module.
• Flow control is enabled by default.
• Flow control will be on if autonegotiation is disabled on both ends of the link.

The Cisco SM-X-6X1G and Cisco SM-X-4X1G-1X10G module supports the auto-detection and auto-failover feature from Cisco IOS XE release 3.16 onwards, You need to upgrade to Cisco IOS XE release 3.16 to configure this feature on the Cisco SM-X-6X1G and Cisco SM-X-4X1G-1X10G module. You can configure the media for failover redundancy when the network goes down.

To specify VLAN classification, use the following commands in physical router configuration mode:

To save your running configuration to nonvolatile random-access memory (NVRAM), use the following command in privileged EXEC configuration mode:

For information about managing your system image and configuration files, refer to the Cisco IOS Configuration Fundamentals Configuration Guide and Cisco IOS Configuration Fundamentals Command Reference that correspond to your Cisco IOS software release.

You can shut down and restart any of the interface ports on a SM independently of each other. Shutting down an interface stops traffic and enters the interface into an “administratively down” state.

There are no restrictions for online insertion and removal (OIR) on Cisco SM-X-6X1G and Cisco SM-X-4X1G-1X10G. Cisco SM-X-6X1G and Cisco SM-X-4X1G-1X10G can be removed from a SIP at any time. SIPs populated with any type of SMs can be removed from the router at any time.

If you are preparing for an OIR of a SM, it is not necessary to independently shut down each of the interfaces prior to deactivation of the SM. The hw-module subslot stop command automatically stops traffic on the interfaces and deactivates them along with the SM in preparation for OIR.

In similar fashion, you do not need to independently restart any interfaces on a SM after OIR of a SM or SIP.

To shut down an interface on a SM, use the following command in interface configuration mode:

To restart an interface on a SM, use the following command in interface configuration mode:

To configure Ethernet flow control per queue per port, use the following commands in the interface configuration mode:

To find detailed interface information on a per-port basis for the Cisco SM-X-6X1G and Cisco SM-X-4X1G-1X10G, use theshow interfaces gigabitethernet command.

The following example provides sample output for interface port 0 on the SM located in the top subslot (0) of the SIP that is installed in slot 2 of the Cisco ISR 4451-X:

router# show interface gigabitEthernet 2/0/0

GigabitEthernet2/0/0 is up, line protocol is up
  Hardware is SM-X-4X1G-1X10G, address is a44c.119e.0884 (bia a44c.119e.0884)
  Internet address is 3.0.0.1/24
  MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not supported
  Half Duplex, 100Mbps, link type is force-up, media type is RJ45
  output flow-control is on, input flow-control is on
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output 00:00:55, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 440722919
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     557663005 packets input, 33459780300 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     451428325 packets output, 27800558158 bytes, 0 underruns
     0 output errors, 0 collisions, 7 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

Use the following show commands to verify the configuration and classification counters on an interface:

The following example shows how to enter the global configuration mode to specify the interface that you want to configure, configure an IP address for the interface, and save the configuration. This example configures interface port 0 on the SM that is located in subslot 0 of the SIP that is installed in slot 2 of the Cisco ISR 4451-X:

! Enter global configuration mode.

!

Router# configure terminal 

! Enter configuration commands, one per line. End with CNTL/Z.

!

! Specify the interface address.

!

Router(config)# interface gigabitethernet 2/0/0 

!

! Configure an IP address.

!

Router(config-if)# ip address 192.168.50.1 255.255.255.0 

!

! Start the interface.

!

Router(config-if)# no shut 

!

! Save the configuration to NVRAM.

!

Router(config-if)# exit 

Router# copy running-config startup-config 

The following example shows how to change the default MAC address on the interface to 1111.2222.3333:

! Enter global configuration mode.

!

Router# configure terminal 

! Enter configuration commands, one per line. End with CNTL/Z.

! 

! Specify the interface address

!

Router(config)# interface gigabitethernet 2/0/0 

!

! Modify the MAC address.

!

Router(config-if)# mac-address 1111.2222.3333 

The following example shows how to set the MTU interface to 9216 bytes.

Note	The SM automatically adds an additional 22 bytes to the configured MTU interface size.

! Enter global configuration mode.

!

Router# configure terminal 

! Enter configuration commands, one per line. End with CNTL/Z.

! 

! Specify the interface address

!

Router(config)# interface gigabitethernet 2/0/0 

!

! Configure the interface MTU.

!

Router(config-if)# mtu 9216 

The following example shows how to create the subinterface number 268 on SM interface port 2 (the third port), and configure the subinterface on the VLAN with the ID number 268, using IEEE 802.1Q encapsulation:

! Enter global configuration mode.

!

Router# configure terminal 

! Enter configuration commands, one per line. End with CNTL/Z.

! 

! Specify the interface address

!

Router(config)# interface gigabitethernet 2/0/1.268 

!

! Configure dot1q encapsulation and specify the VLAN ID.

!

Router(config-subif)# encapsulation dot1q 268