Brocade 6910 Ethernet Access Switch Configuration Guide (Supporting R2.2.0.0) - Manual (Page 779)

Brocade 6910 Ethernet Access Switch Configuration Guide 723
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Port Configuration
Command Usage
• This feature loops incoming frames back to the source. The source MAC address is swapped
with the destination MAC address, reflecting incoming frames back to the source. Testing and
network initialization are critical processes in metro Ethernet networks. Traditional methods of
testing required two technicians and two test sets, one at the remote location and one at the
service provider’s core network. The technicians would test one device at a time to verify
network continuity and performance. This process is time consuming, and cannot be deployed
on demand.
The introduction of the “reflector” function in Ethernet CPE equipment such as this switch
simplifies testing by swapping the source and destination MAC address of a frame, and
sending it back out the same interface it came in on. This allows a single test set to be
installed many hops from the device under test. By enabling the reflector function on remote
CPE devices, an RFC 2544 test generator installed at the network core can use a single test
set for on demand testing of the entire metro Ethernet network serviced from that core. All
frames from the test set will traverse the network, hit the reflector and return to the test set.
The test set can then analyze and display the results. In addition, one single RFC2544 test set
can be used to support the entire metro Ethernet network in the core location.
• This command can bind the loopback function to a specific port, or to a port and one or more
associated VLANs. When loopback is bound to a port and associated VLANs, the port does not
need to be explicitly assigned as a member of the specified VLANs. As long as the inbound
frames match the loopback settings, the frame will be reflected back to the source. Also, note
that the other VLANs to which the port has not been associated with the loopback function will
continue to process traffic normally, allowing non-disruptive loopback testing.
• The loopback function cannot be enabled on a trunk, but can be enabled on any member port
of a trunk.
• Up to 40 VLANs can associated with a port for the loopback function, and up to 240 loopback
entries are supported by the system. Use the Show Resources page to display the total number
of loopback entries supported the by system, the number of available entries, and the number
of entries currently configured.
Parameters
These parameters are displayed:
Configure
• Port – Switch port identifier.
• Status – Enables or disables loopback testing.
• VLAN ID – A single VLAN ID or a range of IDs. (Range: 1-4093)
Show Information
• Port – Switch port identifier.
• Type – Shows if loopback testing is enable for the port, or for the port and one or more
associated VLANs.
• VLAN ID – A single VLAN ID or a range of IDs. (Range: 1-4093)
Show Resources
• Total Resources – The total number of loopback entries supported the by system.
• Free Resources – The number of available loopback entries.
• Resources Used by Users – The number of loopback entries currently configured.