S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
interact with the B port. The traffic is transparently propagated (bridged) over a WAN interface before
exiting the remote B port. This bridge results in both E ports exchanging Class F information that
ultimately leads to normal ISL behavior such as fabric merging and routing.
FCIP links between B port SAN extenders do not exchange the same information as FCIP links between
E ports, and are therefore incompatible. This is reflected by the terminology used in FC-BB-2: while VE
ports establish a virtual ISL over an FCIP link, B ports use a B access ISL.
The IPS module and MPS-14/2 module support FCIP links that originate from a B port SAN extender
device by implementing the B access ISL protocol on a Gigabit Ethernet interface. Internally, the
corresponding virtual B port connects to a virtual E port that completes the end-to-end E port
connectivity requirement (see
FCIP Link Terminating in a B Port Mode
The B port feature in the IPS module and MPS-14/2 module allows remote B port SAN extenders to
communicate directly with a Cisco MDS 9000 Family switch, eliminating the need for local bridge
Configuring B Ports
When an FCIP peer is a SAN extender device that only supports Fibre Channel B ports, you need to
enable the B port mode for the FCIP link. When a B port is enabled, the E port functionality is also
enabled and they coexist. If the B port is disabled, the E port functionality remains enabled.
OL-16184-01, Cisco MDS SAN-OS Release 3.x
B access ISL
port adapter (1G)
Cisco MDS 9000 Family CLI Configuration Guide