McDATA StorageWorks 2/140 - Director Switch Planning Manual page 157

R_Port Domain_ID Assignment
The default preferred Domain_ID for each SAN router R_Port is 1.
However, each port should be assigned a preferred Domain_ID (set at
the R_Ports tab of the Fabric Configuration dialog box) that is unique
within the attached fabric. The principal switch in the attached fabric
then attempts to allocate this requested (preferred) Domain_ID to the
R_Port. If the requested value is in use, the principal switch assigns
the first available Domain_ID.
NOTE: If more than one R_Port (from the same router or multiple routers) is
attached to a fabric, each port requires a unique Domain_ID.
The Insistent Domain_ID option (enabled at the R_Ports tab of the
Fabric Configuration dialog box) ensures an R_Port gets a predictable
(assigned) address. However, if the Insistent Domain_ID check box is
enabled for an R_Port and the port does not get the preferred address,
the R_Port segments and does not connect to the fabric. In addition,
R_Ports segment if:
• Two R_Ports physically connect to a single fabric and the
connections are configured (at the SANvergence Manager
application) for attachment to a pair of fabrics.
• Two R_Ports physically connect to two fabrics and the
connections are configured (at the SANvergence Manager
application) for attachment to a single fabric.
It is recommended that insistent (unique) Domain_IDs be assigned to
directors, fabric switches, and R_Ports in routed fabrics. Assigning
Domain_IDs results in known network addresses, predictable device
behavior, and ease of locating and identifying equipment.
Router Fabric Manager
A fabric-attached R_Port acts as a router fabric manager that manages
fabric discovery, device registration, zoning, and other fabric-related
activities between the router and attached fabric. The router fabric
manager provides communication between the fabric's simple name
server (SNS) and the router's metropolitan simple name server
(mSNS) or Internet simple name server (iSNS). When a SAN router
connects to a Fibre Channel fabric, device information is mutually
exchanged. The router and the fabric's principal switch register any
new device information with their respective name servers.
Implementing SAN Internetworking Solutions
Implementing SAN Internetworking Solutions
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