My machine is U10 which has hme on pci bus.

# ifconfig hme0
hme0: flags=8a63<UP,BROADCAST,NOTRAILERS,RUNNING,ALLMULTI,SIMPLEX,MULTICAST> mtu 1500
	address: 08:00:20:a7:8e:d2
	media: Ethernet autoselect (10baseT)
	status: active
(snip)

I found a problem...

If I set hme media
  autoselect (and link up 10baseT)
or
  10baseT manually
, hme did NOT behave SIMPLEX...

# ping6 -I hme0 ff02::1

PING6(64=40+8+16 bytes) fe80::a00:20ff:fea7:8ed2%hme0 --> ff02::1
24 bytes from fe80::a00:20ff:fea7:8ed2%hme0, icmp_seq=0 hlim=64 time=0 ms
24 bytes from fe80::a00:20ff:fea7:8ed2%hme0, icmp_seq=0 hlim=64 time=0 ms(DUP!)
24 bytes from fe80::a00:20ff:fea7:8ed2%hme0, icmp_seq=1 hlim=64 time=0 ms
24 bytes from fe80::a00:20ff:fea7:8ed2%hme0, icmp_seq=1 hlim=64 time=0 ms(DUP!)

--- ff02::1 ping6 statistics ---
2 packets transmitted, 2 packets received, +2 duplicates, 0% packet loss
round-trip min/avg/max/std-dev = 0.000/0.000/0.000/0.000 ms

no problem in other media. uum...

Your hme works correctly ? on pci ? on sbus ???

I attach ad-hoc patch this mail...

# sorry, this is edited manually, so offset may be different

-- 
FUKAUMI Naoki

--- sys/dev/ic/hme.c.orig	Mon Nov 12 14:07:29 2001
+++ sys/dev/ic/hme.c	Mon Nov 12 14:39:23 2001
@@ -759,6 +742,7 @@
 	int ix, len;
 {
 	struct ifnet *ifp = &sc->sc_ethercom.ec_if;
+	struct ether_header *eh;
 	struct mbuf *m;
 
 	if (len <= sizeof(struct ether_header) ||
@@ -780,6 +764,13 @@
 		return;
 	}
 
+	eh = mtod(m, struct ether_header *);
+	if (memcmp(LLADDR(ifp->if_sadl), eh->ether_shost,
+	    ETHER_ADDR_LEN) == 0) {
+		m_freem(m);
+		return;
+	}
+
 	ifp->if_ipackets++;
 
 #if NBPFILTER > 0