Alcatel Carrier Internetworking Solutions Omni Switch/Router - Manual (Page 666)

AutoTracker VLANs
Page 22-6
Devices that Generate a Secondary Traffic Type
Source devices sometimes generate more than one traffic type; for example, a device could
generate
IP traffic primarily but also generate a secondary stream of AppleTalk. When a
device generates secondary traffic that does not match any existing VLAN policy, that traffic is
grouped into the primary VLAN of which the device is a member.
To continue the example, if a device generates both IP and AppleTalk, and both an IP VLAN
and an AppleTalk VLAN exist, that device is made a member of both VLAN s and no problem
occurs. If, however, an AppleTalk VLAN does not exist, all traffic from that device is grouped
into the existing VLAN of which the device is a member – in this example, the IP VLAN . This
can cause communication problems, as explained below. For this reason, it is advisable to
create VLAN s that accommodate all known network traffic.
Omni Switch/Router
12345678
123456
In this example Device A is
assigned to default
VLAN #1
because it does not match any
existing
VLAN policy.
Devices B and C are assigned to
VLAN 2 because they generate IP
traffic. The secondary AppleTalk
traffic Device C generates is also
grouped into
VLAN 2, since the
AppleTalk traffic does not match
any existing
VLAN policy.
The result is that Devices A and
C are unable to communicate.
Creation of an AppleTalk proto-
col VLAN solves this problem. If
a n A p p l e T a l k
V L A N e x i s t s ,
Device A will be assigned to it
and removed from Default
VLAN
#1. Device C will be assigned to
both the
IP VLAN and the Apple-
Talk VLAN . Devices A and C can
then communicate.
VLAN 1
(default VLAN #1)
no policies allowed
VLAN 2
IP protocol VLAN
Group 2
A s s i g n m e n t o f d e v i c e s t o
default
VLAN when they do not
match any policies is enabled.
Device B
IP traffic only
Device A
AppleTalk traffic only
Device C
IP and AppleTalk
traffic