Hi All,  I'm doing some self-guided Wireshark training on Udemy in order to better understand and troubleshoot my network. One of the topics today was retransmission, which I see a lot of in my captures and something I haven't been able to understand...

I recently replaced the core switch at one of my sites that consisted of two separate C9300-48Ts and three other off brand switches and installed a new stack with a C9300X-48HX, C9300-24S and a C9300-48T (running 17.12.5). This is a layer 2 network c...

I recently got an IEM-16P expansion module for an IE-3300-8P2S and cannot get it to pass POE. I've tried the expansion module on two separate 3300 base switches with the same result.  With a 48VDC 480W power supply I can power an IE-3300-8P2S with an...