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Allied Telesis AT 9924SP AT-9924SP-30 AT-9924SP-30 Software Manual page 54

Configure epsr (ethernet protection switching ring) to protect a ring from loops

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3. The transit node receives a Ring-Down-Flush-FDB message
In the meanwhile, the master node has received a Link-Down message from the switch at the
other end of the broken link (in step
the ring is broken and acts accordingly. As part of the recovery process, the master node
sends a Ring-Down-Flush-FDB message. The transit node receives this message and flushes
its forwarding database.
This is the packet shown in step
EPSR Port1 Rx:
00bb0100 00541ee9 00000000 0000cd28 0619990b 00400107 03e80000 00000000
cd280619 00000000 02000000
EPSR Port1 Rx:
-----------------------------------------------------------------------
-----------------------------------------------------------------------
Flush FDB EPSR: test
4. The transit node sends a Link-Down message
The transit node realises that its port is down, sends a Link-Down message, sends a trap, and
changes its state to Link-Down. The transit node sends this message some time after the link
actually went down, because the ring ports are 1000M ports (see
Times" on page
traffic flow. The master node detected the link failure by receiving a Link-Down message
from the other side of the link.
This is the Link-Down message that the master switch received in step
Manager 9924-B>
EPSR test, Port 2 port down
Flush FDB EPSR: test
Block EPSR:test port:2 VLAN:2
EPSR Port1 Tx:
00bb0100 00542484 00000000 0000cd24 024f990b 00400108 03e80000 00000000
cd24024f 00000000 04000000
EPSR Port1 Tx:
-----------------------------------------------------------------------
-----------------------------------------------------------------------
EPSR INFO: Send trap EPSR:test oldState:LINK-UP newState:LINK-DOWN
nodeType:TRANSIT
EPSR test oldState:LINK-UP newState:LINK-DOWN
Page 54 | AlliedWare™ OS How To Note: EPSR
00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b
TYPE = RING-DOWN-FLUSH-FDB
CTRL VLAN = 1000
HELLO TIME = 0
HELLO SEQ = 0
vid: 2
30). Note that by this stage the ring has already changed topology to restore
vid: 2
00e02b00 00040000 cd24024f 8100e3e8 005caaaa 0300e02b
TYPE = LINK-DOWN
CTRL VLAN = 1000
HELLO TIME = 0
HELLO SEQ = 0
3 on page
48). Therefore, the master node realises that
4 on page 49
of the master node debug output.
STATE = FAILED
SYSTEM = 00-00-cd-28-06-19
FAIL TIME = 0
STATE = LINK-DOWN
SYSTEM = 00-00-cd-24-02-4f
FAIL TIME = 0
Debugging
"Ports and Recovery
5 on page
49.

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