HP StorageWorks Fabric OS 5.3.x administrator guide (5697-0244, November 2009)

Fabric OS 5.3.0 administrator guide 241
higher router cost IFLs (for example ports 8–15). For VEX_Ports, you would use ports in the range of
16 -23 o r 24 -31.
You can connect multiple EX_Ports or VEX_Ports to the same edge fabric. The EX_Ports can all be on the
same 400 MP Router or 4/256 SAN Director with an B-Series MP Router blade, or they can be on multiple
routers. Multiple EX_Ports create multiple paths for frame routing. Multiple paths can be used in two
different, but compatible, ways:
• Failing over from one path to another
• Using multiple paths in parallel to increase effective data transmission rates
EX_Ports and VEX_Ports, when connected, are assigned different router port costs and traffic will flow only
through the EX_Ports. Routing failover is automatic, but it can result in frames arriving out of order when
frames take different routes. The 400 MP Router or 4/256 SAN Director with an B-Series MP Router blade
can force in-order delivery, although frame delivery is delayed immediately after the path failover.
Source EX_Ports can balance loads across multiple destination EX_Ports attached to the same edge fabric
using exchange IDs from the routed frames as keys to distribute the traffic.
Setting a proxy PID
When a 400 MP Router or 4/256 SAN Director with an B-Series MP Router blade is first configured, the
PIDs for the proxy devices are automatically assigned. Proxy PIDs (as well as phantom domain IDs) persist
across reboots.
The most common situation in which you would set a proxy PID is when you replace a switch. If you
replace the switch and want to continue using the old PID assignments, you can configure it to do so; this
value remains in the system even if the blade is replaced. To minimize disruption to the edge fabrics, set
the proxy PIDs to the same values used with the old hardware.
The fcrProxyConfig command displays or sets the persistent configuration of proxy devices. Used with
the -s slot option, it can also influence the assignment of the xlate domain port number (which is used to
determine the Area_ID field of the PID) and the Port_ID field. Like the PIDs in a fabric, a proxy PID must be
unique. If the slot argument results in a duplicate PID, it will be ignored. Proxy PIDs are automatically
assigned to devices imported into a fabric, starting at f001. For Proxy IDs projected to a McDATA edge
fabric in McDATA fabric mode, use valid ALPAs (lower 8 bits).
See the fcrProxyConfig command in the Fabric OS Command Reference Manual for more details.
Use the fcrXlateConfig command to display or assign a preferred domain ID to a translate domain.
See the fcrXlateConfig command in the Fabric OS Command Reference Manual for more details.
Matching fabric parameters
By default, EX_Ports and VEX_Ports detect, autonegotiate, and configure the fabric parameters without user
intervention.
You can optionally configure these parameters manually. To change the fabric parameters on a switch in
the edge fabric, execute the configure command. To change the fabric parameters of an EX_Port on the
4/256 SAN Director with a B-Series MP Router blade, use the portCfgEXPort command. If you want to
change the fabric parameters of a VEX_Port, then use the portCfgVEXPort command.
The PID mode for the backbone fabric PID mode and the edge fabric PID mode do not need to match, but
the PID mode for the EX_Port or VEX_Port and the edge fabric to which it is attached must match. You can
statically set the PID mode for the fabric by using the -p option with the portCfgEXPort command. (Use
the -t option to disable the negotiate fabric parameter feature). Otherwise, the PID mode is
autonegotiated. The various edge fabrics may have different PID modes.
Fabric parameter settings, namely, E_D_TOV (error-detect timeout value), R_A_TOV (resource-allocation
timeout value), and PID format, must be the same on EX_Ports or VEX_Ports and on the fabrics to which
they are connected. You can set the PID format on an EX_Port when you configure an interfabric link.
The default values for E_D_TOV and R_A_TOV for an EX_Port or VEX_Port must match those values on other
Brocade switches. Only if you have adjusted these parameters for the edge fabric do you need to adjust
them for an EX_Port or VEX_Port.