Thank you for researching this.
This behaviour is caused by a stupid mistake in the driver's code, where
the receiver is disabled unless either an address is set or the
interface is switched to promiscuous mode.
The following patch will fix the problem.
Index: if_sq.c
===================================================================
RCS file: /OpenBSD/src/sys/arch/sgi/hpc/if_sq.c,v
retrieving revision 1.28
diff -u -p -r1.28 if_sq.c
--- if_sq.c 22 Jan 2017 10:17:37 -0000 1.28
+++ if_sq.c 2 Mar 2017 07:13:48 -0000
@@ -580,7 +580,7 @@ sq_set_filter(struct sq_softc *sc)
/*
* Unless otherwise specified, always accept broadcast frames.
*/
- if ((sc->sc_rxcmd & ~RXCMD_REC_MASK) == RXCMD_REC_NONE)
+ if ((sc->sc_rxcmd & RXCMD_REC_MASK) == RXCMD_REC_NONE)
sc->sc_rxcmd |= RXCMD_REC_BROAD;
}
