GarrettCom Magnum 700X manual Cases where an internal packet is filtered

Internal packets are forwarded when the destination is NOT IN the address table.

FWD-X LED “ON”

Magnum 700X Mini-Concentrators Installation and User Guide (05/98)

1.Bridge Functions: Each BPM card contains a compact local bridge module which filters and forwards packets at full Ethernet wire speed. These micro-bridges are self learning and have small (256 user) address tables.

Packet filter/forward decisions are made based on whether the packet source is internal (originates within the local Magnum Hub/Stack) or external (originates from upstream on the attached segment). If the

packet’s source is internal, it is forwarded to the outside only if the destination address is not in the address table. Figure 4.2a shows an internal packet being forwarded to the

external segment.

Figure 4.2b show the	Figure 4.2a: Internal Packet Forwarded
cases where an internal packet is filtered.
When the packet’s source is external, it	Internal packets
is forwarded to the inside only if the	are filtered when
	the destination is
destination address is in the address	IN the address
	table.
table.
The filter/forward handling of
external packets are shown in figures	Figure 4.2b: Internal Packets Filtered
4.2c and 4.2d respectively. When an	External packets
internal packet’s source address is not	are forwarded when
	the destination is
already in the address table, it is	IN the address
written there. This happens when a	table.
	FWD-I LED “ON”

node first sends a packet upon bridge initialization.

Figure 4.2c: External Packet Forwarded

Note, therefore, that the address table automatically learns addresses, specifically, it learns those connected via the RPMs in the front of the 700X, a number typically well under the 256 table addresses size.

GARRETT

27