The ZTX-7250S-16S-F MSS Appliance provides 50 Gbps Encrypted / 100 Gbps aggregate throughput and has 16x 10G Ethernet ports (SFP+) and 4x Network Interface Module (NIM) expansion slots. The ports are labeled as 1 through 16.

In the EOS CLI, all the onboard ports have the prefix 1 (Et1/X, X from 1-16) to indicate that they are on the main system rather than the pluggable NIM cards.

This section describes interface capabilities. These capabilities are displayed using the following command:

show interfaces <INTF> hardware default

Interface speed and auto-negotiation depend on the mac/phy capabilities, the front panel connector, and the type of transceiver inserted. The default capabilities of the device are as follows:

When a transceiver is inserted, EOS recognizes the transceiver type. To see which types of transceivers are supported, refer to the Supported Transceivers. If the transceiver is supported, EOS decides the capable speed and auto-negotiation satisfied by both the hardware and the modules. To view the show commands and examples output, refer to Show Commands for Speed and Auto-negotiation Capabilities.

When there is no speed configuration on the interface, EOS applies the default speed. On an RJ45 port, the default configuration is auto-negotiation, enabled with 10G. On an SFP port, the default configuration is auto-negotiation, disabled with 10G.

This section describes the configuration of interface speed and auto-negotiation.

Interface speed and auto-negotiation are configured using the speed speed-lane-token command, as shown in the following examples:

To configure 10G speed with auto-negotiation disabled:

Arista(config-if-Et1/1)# speed 10g

To configure 1G speed with auto-negotiation disabled:

Arista(config-if-Et1/1)# speed 1g

To configure 10G speed with auto-negotiation enabled:

Arista(config-if-Et1/1)# speed auto 10gfull

To configure 5G speed with auto-negotiation enabled:

Arista(config-if-Et1/1)# speed auto 5gfull

To configure 2.5G speed with auto-negotiation enabled:

Arista(config-if-Et1/1)# speed auto 2.5gfull

To configure 1G speed with auto-negotiation enabled:

Arista(config-if-Et1/1)# speed auto 1gfull

To remove speed configuration:

Arista(config-if-Et1/1)# no speed

Use the following show command to check whether interfaces are connected, not connected, or error-disabled:

Arista(config)# show interfaces status
Port Name Status Vlan Duplex SpeedType Flags Encapsulation
Et1/1 connectedrouted full 10G10GBASE-T
Et1/2 connectedrouted full 10G10GBASE-T
Et1/3 connectedrouted full 10G10GBASE-T
Et1/4 connectedrouted full 10G10GBASE-T
Et1/5 connectedrouted full 10G10GBASE-CR
Et1/6 connectedrouted full 10G10GBASE-CR
Et1/7 connectedrouted full 10G10GBASE-CR
Et1/8 errdisabledrouted full 100G 10GBASE-CR

Use the following show command to display why an interface is error-disabled:

Arista(config)# show interfaces ET1/8 status errdisabled
PortName Status Reason
----------- ---------------- ------------ -------------------
Et1/8errdisabled speed-misconfigured

When a transceiver is in an error-disabled state due to a misconfigured speed, the following syslog message is logged:

bessd[4392]: %ETH-4-LINKMODEUNSUPPORTED: Unsupported link mode 100G/full for interface Ethernet1/8
Ebra: %ETH-4-ERRDISABLE: speed-misconfigured error detected on Ethernet1/8.

Supported speed and auto-negotiation are displayed by the following command when the transceiver is inserted:

show interfaces <INTF> hardware

Arista(config)#show int ET1/1 hardware Ethernet1/1
Model: ZTX-7250F-16S-F 
Type: 10GBASE-SR
Speed/duplex: 10G/full(default)
Flowcontrol: rx-(off),tx-(off)
Error correction: unsupported

For details about the different transceivers, modules, and cables, visit https://www.arista.com/en/products/transceivers-cables.

The first eight ports (ports 1-8) are subject to minor differences in transceiver configuration.

The shut and no shut configuration commands may not use the SFP transceiver’s TX Disable control register software. Instead, the TX Disable hardware low-speed pin signal will always be used. This does not result in operational or behavioral differences for Arista Networks transceivers.

The configuration commands transceiver frequency and transceiver channel are not supported on the first eight ports (ports 1-8).

When using the locator-led interface CLI command, the first eight port LEDs (ports 1-8) may flash at a different rate than the last eight port LEDs (ports 9-16).

Auto-negotiation parallel detection on ports 1-8.

Parallel detection is used on the ports 1-8, where the ports can perform auto-negotiation. This happens when the link partner might not support auto-negotiation, or the auto-negotiation is disabled on the device. In this condition, the port capable of auto-negotiation can determine if it should use auto-negotiation and can match the speed with the other device.

Parallel detection is enabled by default and cannot be disabled. Links can come up with a mismatch in auto-negotiation configuration. If auto-negotiation is enabled on Arista ZTX-7250F-16S-F ports 1-8, but not on the link partner and links can be established, then auto-negotiation status is successful.

Arista(config-if-Et1/1)#show int st
Port Name Status Vlan Duplex SpeedType Flags Encapsulation
Et1/1 connectedrouted a-full a-1G 1000BASE-SX

LinkPartner(config)#show int ET25 st
Port Name Status Vlan Duplex SpeedType Flags Encapsulation
Et25connected1full 1G 1000BASE-SX

Arista(config-if-Et1/1)#show int ET1/1 negotiation detail Ethernet1/1
Auto-Negotiation Mode 1000BASE-X (IEEE Clause 37)
Auto-Negotiation Status Success
Speed DownshiftingNot Applicable

Advertisements Speed Duplex Pause
 ----------------- ---------- --------------------
Local1Gfull Disabled
Link Partner 1Gfull Disabled

Resolution 1Gb/s full Rx=Unsupp.,Tx=Unsupp.