Symptom

Configured the "no negotiation auto" and "speed xxx"/ "duplex xxx" on C9300L Gi0/0, then the below message was printed, Gi0/0 went into Line protocol down, it will be up after a while. ----------------------------- Switch(config)#int gi0/0 Switch(config-if)#no negotiation auto Switch(config-if)#speed 100 Switch(config-if)# %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to down %IOSXE-3-PLATFORM: Switch 1 R0/0: kernel: igb 0000:13:00.0: Unsupported Speed/Duplex configuration ----------------------------- It didn't work as the following document. ----------------------------- Interface and Hardware Components Configuration Guide, Cisco IOS XE Amsterdam 17.3.x (Catalyst 9300 Switches) https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9300/software/release/17-3/configuration_guide/int_hw/b_173_int_and_hw_9300_cg/configuring_ethernet_management_port.html Supported Features on the Ethernet Management Port The Ethernet management port supports these features: Speed: 10 Mb/s, 100 Mb/s, 1000 Mb/s, and autonegotiation Duplex mode: Full, half, and autonegotiation -----------------------------

Conditions

Configured the "no negotiation auto" and "speed xxx"/ "duplex xxx" on C9300L Gi0/0,

Workaround

none

Further Problem Description