SAN Design: March 29, 2001 3:18 pm
53-0001575-01 BROCADE Technical Note Page: 26 of 31
fabric using IP over fibre channel protocol across switch links, thus reducing the need for a large switch management network. This config-
uration requires the primary switch with the Ethernet connection to be configured as the gateway switch for the Fibre Channel IP network.
All other switches would have to have this switch configured as the gateway address. This reduces the complexity of having a full Ethernet
switch management network, but does make the gateway switch a single point of failure for the management interface.
Web Tools provides the most user friendly interface to switch management. Within WebTools there is also the option to connect to a switch
via telnet session should a command line interface be needed to set special debugging options or if the administrator prefers a command
line interface over a GUI.
A typical management approach would be to use an SNMP management tool to monitor the switch network (along with other network ele-
ments) and to set alarms/traps for key events that would trigger an administrative intervention. This could be switch down, port down, fan
failure, power supply failure, temperature out of range and similar events that require intervention. The administrator would get either the
IP address of the switch or (if the SNMP tool has been setup this way) an icon of the switch indicating an alarm. The admin could click on
the switch and have the SNMP management tool invoke WebTools for that switch. Further diagnosis and trouble shooting would occur via
the WebTools interface.
3.9 NON PUBLIC DEVICES AND EXISTING FC-AL DISK EQUIPMENT
Fibre Channel Arbitrated Loop (FC-AL) technology is used by a number of manufacturers in disk storage systems. It is the usual format
employed in JBODs and also the technology used behind some storage RAID controllers (which can also present a FC-AL interface or Fab-
ric interface or both to a switch). BROCADE supplies a switch mode designated QuickLoop™ that allows for the attachment of non-public
FC-AL devices to the switch. If the host bus adapter driver does not support Fabric attachment, and only supports a private interface, then a
QuickLoop connection to the switch is required. QuickLoop is supported only on the SilkWorm 2000 series switches. The entire switch can
be a QuickLoop enabled switch (model 2100 and 2010) or a fabric switch model can have selected ports configured to be QuickLoop ports
(this is a separately licensed product from BROCADE). Up to two switches can be connected with an ISL to form one logical QuickLoop.
No more than one QuickLoop can be supported between one or two switches. All devices within a QuickLoop can communicate with each
other. Public devices attached to a non-QuickLoop port can communicate to the private QuickLoop devices using translative mode address-
ing (more on this later). The advantage of a switch employed in the QuickLoop mode over a hub is the fact that the switch provides for full
bandwidth on each port. If multiple devices are used on multiple QuickLoop ports, each set of devices attached to a physical port share the
full port bandwidth of 100 MBytes/second. In a hub attached device configuration all devices on a single loop share the maximum band-