Is IRF between switch models limited to the switch series? And can you IRF over LinkAgg?

[Kumba]

So is IRF mixing of different switch models only generally applicable within the same series? I.E. I can IRF a 5820 and 5830, or a 5900 and a 5920, but I can't IRF a 5830 to a 5920?

Just trying to understand what the rules are in general for this. I currently have a pair of 5830's in an IRF as my 'core' at a data center, but I need to add more 10G ports then what the expansion ports will give me. I was looking at using two 5920's to give me the 10G port expansion I am looking for. It would be nice if I could add these two to the IRF of the 5830's but I am guessing that won't be supported.

So if I assume that I can't IRF the 5830 and 5920, I was looking at moving away from the 5830 and using two 5900's (JG510A) with the two 5920 (JG296A). If I do this would I be able to take a QSFP to 4xSFP cable and aggregate the 4 ports together on the 5920 for IRF with the 5900? That way I can maintain 40Gb IRF throughout? Or would I be limited to only 10GB links between the 5900 and 5920?

[parnassus]

If I'm not mistaken Heterogeneous IRF feature is supported only on specific Switch series: as examples, on 5820X with 5800 and on 5920 with 5900...I believe you can deploy an IRF domain with a mix of 5830 and 5920...but you should be able to mix 5900 with 5920...to be exactly sure you should read IRF Configuration guide of each one involved Switch series.

With regards to logical IRF port(s): on 5900 IRF port(s) can be created using either (up to 4) single QSFP+ (40Gbps) physical interface or by (up to 4) single QSFP+ (40Gbps) physical interface splitted into 4 SFP+ (4 x 10Gbps)...that's using breakout...suppose you're going to use one QSFP+ splitted into 4 SFP+ (breakout) on 5900AF then this is "all or none", it means that you should use all (or none) splitted 10Gbps interfaces to for one (or more than one) logical IRF port...so on the other IRF member (5920AF) you're connecting this IRF port you must use 4 SFP+ ports (again, all or none) following SFP+ interface restrictions related to IRF port binding (same is valid for QSFP+).