DLPI Programmer's Guide

26 Chapter 1

Introduction to DLPI

Promiscuous Mode Clariﬁcations

The following deﬁnitions are being deﬁned for the various levels of

promiscuous mode.

DL_PROMISC_PHYS—Before the STREAM has been bound (with the

DL_BIND_REQ primitive), the DLPI user receives all trafﬁc on the wire

regardless of SAP or address. After the STREAM has been bound, the

DLPI user receives all trafﬁc on the wire that matches the protocol(s) the

user has bound to on the promiscuous STREAM; this includes protocols

bound with the DL_SUBS_BIND_REQ.

DL_PROMISC_SAP—Before the STREAM has been bound (with the

DL_BIND_REQ primitive), the DLPI user receives all trafﬁc destined for

this interface (physical addresses, broadcast addresses or bound

multicast addresses) that matches any SAP enabled on that interface.

After the STREAM has been bound, the DLPI user receives only those

packets originally destined for the interface that match one of the

protocol(s) bound on the promiscuous STREAM.

NOTE The Series 700 core and EISA LAN and100VG drivers are currently the

only hardware supporting promiscuous mode which is known to have a

MULTICAST_ALL command. This command allows the chip to receive

all packets with the group bit set. The other drivers will require that the

hardware be in full promiscuous mode and then ﬁlter on the group bit in

the driver.

DL_PROMISC_MULTI—Before the STREAM has been bound (with the

DL_BIND_REQ primitive), the DLPI user receives all multicast packets

on the wire regardless of the SAP. After the STREAM has been bound,

the DLPI user receives all multicast packets that match one of the

protocol(s) bound on the promiscuous STREAM.

NOTE Each LAN interface currently allows only one stream to enable the

promiscuous mode service. This restriction will be removed with a future

release of the DLPI provider.