B&B Electronics 856-14205--29 - Manual - Manual (Page 14)

Configuration
9
LOOPBACK TESTING ON REMOTE OR STANDALONE
NO LOOPBACK, NORMAL TRAFFIC MODE
The standard mode in which the units function, either as standalone or
Host/Remote.
LOOPBACK ENABLED
Loopback mode without address swap
LOOPBACK, SOURCE/DESTINATION ADDRESS SWAP
A Layer 2 Ethernet switch will discard all received packets with the same MAC
address as sent packets. To avoid this issue the Loopback feature can swap the
source and destination MAC addresses on the looped data. (This selection can
cause a frame with a multicast source address to be created, which violates the
IEEE standard.)
LOOPBACK, ADDRESS SWAP AND CLEAR MULTICAST
BIT
In addition to swapping the source and destination MAC addresses on the looped
data, the Loopback feature can also be set to clear the multicast bit. This allows
the looped data to avoid being blocked by any multicast settings.
LOOPBACK TESTING IN A HOST/REMOTE
CONFIGURATION
The iMcV-Giga-FiberLinX-III is strictly a CPE device; configuration on a Host
would require an iMcV-Giga-FiberLinX-III; select No Learning on OPTICS and
DATA Ports on the Host; on the Remote, choose SRC/DST Address Swap or
Address Swap and Clear Multicast Bit.