So we use ASR920-12CZA and ASR920-24SZ-M on our networks. Recently we started doing the cabling between different routers of the same cabinet using Twinax cables; however, I am seeing very inconsistent compatibility issues In my lab, a Twinax cable (SFP-H10GB-CU2M) between 1G SFP ports on the ASR920-12CZA working in 1G mode In my lab, a Twinax cable (SFP-H10GB-CU2M) between dual rate 1G/10G SFP ports on the ASR920-12CZA working in 1G mode In the field, a Twinax cable (SFP-H10GB-CU1M) between dual rate 1G/10G SFP ports on the ASR920-12CZA failing to negotiate at 1G and failing to come up because we don't have a 10G license on these routers (Don't have 10G license in point 2 above, either) Points 2 and 3 are baffling to me, because the router model, IOS image (16.9.3), config are virtually identical; only difference is length of the cable. Still, for point 3, there's an error that the port cannot operate in 10G mode because of a lack of license and stays administratively down.   We also have some ASR920-24SZ-M coming up and now I fear the Twinax won't come up on these routers on the 1G ports in 1G mode.   The datasheet itself doesn't mention 1G compatibility anywhere, but I went ahead because of success in the lab (Points 1 and 2).   Is there any official information about this available?   ... View more