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If a port is pre-configured on a cloudscale switch on impacted code to 'speed 1000' and then a 10g optic is inserted, the link may incorrectly come up instead of being held down due to speed mismatch. Nexus-9000# sh int e1/48 status -------------------------------------------------------------------------------- Port Name Status Vlan Duplex Speed Type -------------------------------------------------------------------------------- Eth1/48 -- connected routed full 1000 10Gbase-LR << up with speed 1000 and 10g optic You may also notice RX power is N/A under "show interface eX/Y transceiver detail" Nexus-9000# show interface ethernet1/48 transceiver detail Ethernet1/48 transceiver is present type is 10Gbase-LR name is CISCO-SUMITOMO part number is SPP5200LR-C6 revision is B serial number is SPCXXXXXXXX nominal bitrate is 10300 MBit/sec Link length supported for 9/125um fiber is 10 km cisco id is 3 cisco extended id number is 4 cisco part number is 10-2457-02 cisco product id is SFP-10G-LR cisco version id is V02 SFP Detail Diagnostics Information (internal calibration) ---------------------------------------------------------------------------- Current Alarms Warnings Measurement High Low High Low ---------------------------------------------------------------------------- Temperature 26.06 C 75.00 C -5.00 C 70.00 C 0.00 C Voltage 3.29 V 3.63 V 2.97 V 3.46 V 3.13 V Current 47.15 mA 90.00 mA 20.00 mA 84.00 mA 24.00 mA Tx Power -2.94 dBm 3.49 dBm -12.21 dBm 0.49 dBm -8.21 dBm Rx Power N/A 3.49 dBm -18.53 dBm 0.49 dBm -14.43 dBm <- No RX power for "up" link
Issue seems to be if the interface is preconfigured w/ 1G and a 10G sfp is inserted
avoid using this combination as this is unsupported. if you need to use a 1g optic in a 10g port, use a QSA adapter and speed 1000 in with a supported 1g optic.
typically, when using a hard-set speed on an interface , in this example 1g , then inserting an optic with a dedicated speed (e.g 10G). Should result in the interface showing as "down (XCVR speed mismatch)" . However, it shows as up and functional.