Allied Telesis AT-9924SP-30, AT-8948 Port 1 comes back up, Transit node receives a Health message

Debugging

4.Port 1 comes back up

The transit node detects that port 1 has come back up. It sends a trap and changes the EPSR state to Pre-forwarding. Note that it leaves port 1 blocked for vlan2, to make sure there are no loops.

Manager 9924-B>

Block EPSR:test port:1 VLAN:2 EPSR test, Port 1 port up

EPSR INFO: Send trap EPSR:test oldState:LINK-DOWN newState:PRE-FORWARDING nodeType:TRANSIT

EPSR test oldState:LINK-DOWN newState:PRE-FORWARDING

5.Transit node receives a Health message

Now that the master node’s primary port is up again, it sends a Health message. Now that the transit node’s port 1 is up again for the control VLAN, the transit node receives the message. This demonstrates that the transit node has only blocked port 1 for the data VLAN, not the control VLAN. EPSR control messages never loop because the master node never forwards them between its ring ports.

Note that the hello sequence number increments from the number it was before the primary port went down, because the master node could not transmit Health messages while the port was down.

This is the packet shown in step 8 on page 39 of the master node debug output.

Manager 9924-B>

EPSR Port1 Rx: 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541dee 00000000 0000cd28 0619990b 00400105 03e80000 00000000 cd280619 00010002 020000fa

EPSR Port1 Rx:

-----------------------------------------------------------------------

TYPE	= HEALTH		STATE	= FAILED
CTRL VLAN	= 1000		SYSTEM	=	00-00-cd-28-06-19
HELLO TIME	=	1	FAIL TIME	=	2
HELLO SEQ	=	250

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Page 44 AlliedWare™ OS How To Note: EPSR