Intel ER8100STUS - Express 8100 Router Reference Manual page 114

Packet processing by
the Destination
Forwarding Tables
102
If the packet does not correspond to the entries in any of the Forwarding Tables,
it can be forwarded on all the links except the link from which it was received or
discarded, depending on the configured destination, source and packet type de-
fault bridging function.
Packets which are received for bridging are checked against one of the Destina-
tion Forwarding Tables—packets with Unicast MAC addresses are only checked
against the Unicast Destination Table and packets with Multicast MAC addresses
are checked against the Multicast Destination Table. The process is as follows:
If table entries with both the destination MAC address and incoming link
1
exist, the packet is labelled for forwarding on the outgoing link(s) defined
by these entries. The packet is then passed to the Source Forwarding Table
for further processing.
If a table entry for the packet defines the outgoing link as
Note
the packet is discarded.
If a table entry exists for the Multicast destination MAC address but the
2
incoming link does not correspond with that of the packet, the packet is dis-
carded.
Unicast destination MAC addresses are allowed from any link.
Note
3 If no entry is found for the destination MAC address and the default action
of the Unicast or Multicast Destination Table (as appropriate) is set to
, the packet is discarded.
card
If no entry is found for the destination MAC address and the default action
4
of the Destination Table (Unicast or Multicast as appropriate) is set to pass,
the packet is labelled for forwarding on all the links except the link on
which it was received. The packet is then passed to the Source Forwarding
Table for further processing.
To avoid "storms", a maximum of 5 packets with unknown Uni-
Note
cast destinations can be forwarded by the router within a 5 sec-
ond period. Additional packets are discarded.
WAN Bridging Services
How Bridging Works
,
None
Dis-