Allied Telesis AT-S25 - Manual (Page 98)

Section II: Local and Telnet Mangement
98
This issue is illustrated in Figure 30. Two VLANs, Sales and Production,
span two AT-8324 Switches. Two links consisting of untagged ports
interconnect the separate parts of each VLAN. If STP is activated on the
switch, one of the links would be disabled. This problem can be avoided
by not activating spanning tree or by connecting VLANs using tagged
instead of untagged ports. (For information on tagged and untagged
ports, refer to Chapter 10, Virtual LANs on page 115.
Figure 30 VLAN Fragmentation
STATUS
RESET
FAULT
MASTER RPS
PWR
10BASE-T / 100BASE-TX
FAST ETHERNET SWITCH
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
10BASE-T / 100BASE-TX
1X 3X 5X 7X
2X 4X 6X 8X
9X 11X 13X 15X
10X 12X 14X 16X
17X 19X 21X 23X
18X 20X 22X 24X
A
B
RS-232 TERMINAL PORT 100M LINK / ACTIVITY 10M LINK / ACTIVITY
HALF DUP/ COL FULL DUP
PORT ACTIVITY
L /A
L /A
D/C
D/C L /A
D/C
Sales
VLAN
Production
VLAN
Production
VLAN
Sales
VLAN
STATUS
RESET
FAULT
MASTER RPS PWR
10BASE-T / 100BASE-TX
FAST ETHERNET SWITCH
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
10BASE-T / 100BASE-TX 1X 3X 5X 7X
2X 4X 6X 8X
9X 11X 13X 15X
10X 12X 14X 16X
17X 19X 21X 23X
18X 20X 22X 24X
A
B
RS-232 TERMINAL PORT 100M LINK / ACTIVITY 10M LINK / ACTIVITY
HALF DUP/ COL FULL DUP
PORT ACTIVITY
L /A
L /A
D/C
D/C L /A
D/C