Application Example 3 - Alcatel Omni Switch/Router User Manual

Application Example 3

Network Address
IPX
Application Example 3 shows two
ning two Omni Switch/Routers.
address policy of network number 100 and Ethernet-
The Problem
In the figure below, when the
seeking a server, Switch 1 assigns the frame to
encapsulation) and then converts the frame to
traverse the ring. When the frame arrives at Switch 2, the network number is not avail-
FDDI
able (since, as previously explained,
bootup) and the frame's encapsulation is no longer Ethernet-
network address policy selects
IPX
sulation, Switch 2 cannot assign the frame to
The Solution
The solution for this problem is to specify a second encapsulation type for
tion to Ethernet- – for example,
II
encapsulation, the frame will match the network address policy for
Switch 2 and can thus be assigned to
encapsulation type must be specified for
transmission in either direction.
This situation can occur whenever translations occur,
such as with bridged
are using
second encapsulation policy for
VLAN
Omni Switch/Router 1
7 8 5 6 3 4 1 2
5 6 3 4 1 2
VLAN B
IPX Network 100
Ethernet- II encap
Workstation Client
IPX
Ethernet- II encap
s and Translated Frames
VLAN
networks connected over a bridged
IPX
B exists in both switches and specifies an
VLAN
client connected to Switch 1 boots up and sends a frame
IPX
VLAN
SNAP
clients do not know their network number at
IPX
members according to network number and encap-
VLAN
VLAN
encapsulation. If
SNAP
B and sent to the server. Note that the second
VLAN
B in both Switches, to accommodate data
VLAN
Please Take Note
rings or Token Rings. If you
FDDI
trunking you do not need to specify a
FDDI
s, because trunked frames are not translated.
With this configuration, a frame sent from the
workstation connected to
and transmitted to Switch 2 over the
could not be assigned to
and thus could not be sent to the Server.
Bridged FDDI Ring
frame has been converted to
encapsulation
SNAP
encapsulation.
II
B (since B specifies Ethernet-
VLAN
encapsulation so that the frame can
– it is now
II
B and send it to the
IPX
B specifies Ethernet-
VLAN
VLAN
network address
IPX
Omni Switch/Router 2
B in Switch 1
VLAN
ring
FDDI
B in Switch 2
VLAN
VLAN
IPX Network 100
Ethernet-
IPX
IPX Network 100
Ethernet-
Application Example 3
ring span-
FDDI
network
IPX
II
. Because the
SNAP
server.
B in addi-
VLAN
or
II SNAP
B when it arrives at
12345678
123456
B
II encap
Server
II encap
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