Dell S4128F-ON port issues
October 24, 2018
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Recently have been working with the S4128 switches. These have been great, and the price point is amazing.
The device comes with 2 ports that can be 10/40/or 100 Gig interfaces (given media). I needed to connect the port via a 40 gig DAC to a Dell server. When I plugged this in, a “show interface eth 1/1/26” would show the interface up, show the DAC model number and then would say “Protocol down”. I thought at first this could be mismatching vlans, etc. But after a few minutes found it had to be a negotiation issue.
After some checking I found this in the config:
interface breakout 1/1/25 map 100g-1x
interface breakout 1/1/26 map 100g-1x
Interface 1/1/26 is my connection to the server. After some digging with Dell we have to modify this. I ran the following command:
interface breakout 1/1/26 map 40g-1x
After running that command a sub-interface showed up. A “Show interface status” presents the following Eth 1/1/26:1. After configuring the sub interface as needed all seemed to work great.
I will post images of interface status later.