The poster (in a machine-translated post from the Spanish-language community) tried to connect two Cisco Business CBS350-24T-4X switches through their SFP+ ports using MikroTik XS+2733LC15D modules. No connectivity is established and the ports end up blocked by the switch's Link Flap Prevention…
The poster asked why third-party SFP modules stopped working after upgrading Cisco switches to IOS 15.2, whereas other vendors accept Cisco or other optics, and whether this is a technical limitation. No model, log output or interface details were given despite requests. In a later update the…
The poster set up several new Cisco Catalyst 9300 switches fitted with C9300-NM-4G network modules, configured GigabitEthernet1/1/1 as a trunk and enabled it, but could not get a link with any of several SFPs. 'show interfaces' reports 'GigabitEthernet1/1/1 is down, line protocol is down…