342-86400-498PS
Issue 1.2
April 2012
Page 41
Copyright
GE Multilin Inc. 2010-2012
The received 802.1Q VLAN ID
22
The „Distributed Port-based VLAN‟ value used when setting up physical
port security
The Destination Port Vector (DPV) defining:
-
the frame‟s source port, for frames received through a local port
23
,
or
-
the location of the ETHER-
1000 unit at the frame‟s source, for
frames received through a Line port
The aging value for each entry
A Unicast or Multicast flag
As Ethernet frames arrive into the ETHER-1000 unit, a lookup of the SA in the
MAC address table is performed. If the same entry already exists on the same
D-PVLAN, its age field is re-initialized and the DPV field is updated (if changed).
Otherwise, the MAC address and frame ingress port will be added (assuming
there is less than 32,768 MAC entries already in the table).
Note:
A new MAC address cannot be added to the “WAN" MAC Address Table
if the table is full. A MAC address entry can only age out of the table. If required,
the table can be cleared by the user, using VistaNET software.
The “WAN” MAC address table is kept sorted to facilitate the fast retrieval of
table entries and to allow the use of all the entries (many switches typically store
less than 10% of their advertised capacity).
All entries in t
he “WAN” MAC address are subject to aging, i.e. an entry will be
removed after a period of inactivity. A MAC address is considered inactive if it
has not been received at any of the ETHER-1000 unit ports (GMII port and two
Line ports) within a specified time interval called Aging Time (defined in each
unit). Aging time is user-configurable (ranging from 30 seconds to 1 hour, or
never).
The Layer 2 switch IC residing on the paddleboard has a 8192-entry MAC
Address Table (called "LAN" MAC Address Table) organized as a hash table with
2048 bins with space for 4 entries per bin. It learns the MAC addresses of the
devices connected to local drop ports as well as the MAC addresses of the
devices connected to remote drop ports that are exchanging traffic with the local
ones. Any unicast frames between local ports are not forwarded to the ETHER-
1000 unit as long as their destination addresses have not aged out. The Aging
22
For QinQ nested frames, this is the VLAN ID carried in the outer tag (tag#1, i.e. the last tag
added, closest to the Ethernet frame header).
23
This can be any of the access ports on the local paddleboard.
