| 21 May 2025 |
 matthewcroughan @fosdem | So if I plugged the rj45 side of a 10G SFP cat6 setup into a 2.5gbps port on my laptop, it's not going to work unless the SFP I have chosen supports "negotiation" | 12:19:27 |
 emily | well, it can depend on both | 12:19:31 |
| emily | some SFP+ modules will do 10G on the host but negotiate multi-gig | 12:19:39 |
| emily | some of them will negotiate slower rates on the host too | 12:19:47 |
| emily | I'm actually busy looking for the perfect Broadcom SFP+ module right now but it's easy to find ones that just do 10G always if that's what the switch want | 12:20:06 |
| emily | * I'm actually busy looking for the perfect Broadcom SFP+ module right now but it's easy to find ones that just do 10G always if that's what the switch wants | 12:20:07 |
| emily | it's pretty easy to find people talking about what they'll negotiate online anyway | 12:20:35 |
| matthewcroughan @fosdem | Yeah the issue is that the laptop things are plugging into will vary from 1/2.5/5 | 12:20:38 |
| matthewcroughan @fosdem | and then if someone comes in with their mega dongles like you, I suppose 10 is possible | 12:21:05 |
| matthewcroughan @fosdem | https://www.amazon.co.uk/QSFPTEK-10GBASE-T-Transceiver-SFP-10G-T-S-UF-RJ45-10G/dp/B081YKGBR4 | 12:23:40 |
| matthewcroughan @fosdem | this one says in the title "1.25/2.5/5/10G-T Copper Module SFP+ " | 12:23:54 |
| matthewcroughan @fosdem | So I assume this means negotiation is possible | 12:24:01 |
| matthewcroughan @fosdem | That's one expensive SFP though | 12:25:16 |
| emily | again you want to be looking at aliexpress | 12:42:00 |
| emily | and not at 30 m ones | 12:42:04 |
| emily | and at multipacks | 12:42:10 |
