CRS310-1G-5S-4S+IN PoE-in passive only, no 802.3af/at

Hardware MikroTik hardware general
1

CRS310 works when powered from CRS328-24P (and PoE voltage is auto-detected as 48V), but doesn’t start when powered from (at least) Netgear GS110TP. Works when powered from the same Netgear switch through RBGPOE-CON-HP (which converts 48V 802.3af to 24V passive PoE), this switch also powers a few other 802.3af compliant devices just fine. So there may be an error in the product page https://mikrotik.com/product/crs310_1g_5s_4s_in - no 802.3af/at, only 18-57V passive PoE-in.

EDIT: CRS310 works when powered from a very old SMCGS8P-Smart switch (latest firmware from 2011, still available from Edge-Core) which also says to be 802.3af compliant (plus one high-power port, but no mention of 802.3at yet), perhaps PoE detection methods have changed since then.

2

PoE 802.3 af/at requires a handshake between PSE and PD. Could be that your CRS310 as PD is marginal at performing handshake (connecting UTP cable out of specs can contribute to it) and your Netgear PoE switch doesn’t like it while the old SMCGS8P might be more forgiving.

CRS328-24P is both 802.3 af/at and passive PoE PSE … quite likely it defaults to passive PoE (because the “hanshake” is almost trivial) and since CRS310 also works as passive PoE PD, things simply work.

3

Necroposting, but in case someone looks for this info, I can confirm the CRS310 only supports passive PoE, despite what the documentation says--just learnt the hard way.