Extreme Networks ExtremeWare 7.2e, Installation And User Manual

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186 ExtremeWare 7.2e Installation and User Guide
Ethernet Automatic Protection Switching
During the time between when the transit node detects that the link is operable again and when the
master node detects that the ring is complete, the secondary port on the master node is still open and
data could start traversing the transit node port that just came up. To prevent the possibility of a such a
temporary loop, when the transit node detects that its failed link is up again, it will perform these steps:
1 For the port that just came up, put all the protected VLANs traversing that port into a temporary
blocked state.
2 Remember which port has been temporarily blocked.
3
Set the state to Preforwarding.
When the master node receives its health-check packet back on its secondary port, and detects that the
ring is once again complete, it sends a message to all its associated transit nodes to flush their
forwarding databases.
When the transit nodes receive the message to flush their forwarding databases, they perform these
steps:
1
Flush their forwarding databases on the protected VLANs.
2 If the port state is set to Preforwarding, unblock all the previously blocked protected VLANs for the
port.
Configuring EAPS on a Switch
This section describes how to configure EAPS on a switch.
Creating and Deleting an EAPS Domain
Each EAPS domain is identified by a unique domain name.
To create an EAPS domain, use the following command:
create eaps <name>
The
name
parameter is a character string of up to 32 characters that identifies the EAPS domain to be
created. EAPS domain names and VLAN names must be unique: Do not use the same name string to
identify both an EAPS domain and a VLAN.
The following command example creates an EAPS domain named “eaps_1”:
create eaps eaps_1
To delete an EAPS domain, use the following command:
delete eaps <name>
The following command example deletes the EAPS domain “eaps_1”:
delete eaps eaps_1