H3C Technologies H3C S12500-X Series Switches - Manual (Page 71)

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Configuring FC routing and forwarding
Overview
Routing and forwarding in an FC SAN is achieved through FCF switches. When an FCF switch receives
a packet, the FCF switch selects an optimal route based on the destination address and forwards the
packet to the next FCF switch in the path until the packet reaches the last FCF switch, which forwards the
packet to the destination node.
Routing provides the path information that guides the forwarding of packets.
Routing table and FIB table
An FCF switch determines the best routes by using its routing table and sends those routes to the FIB table,
which guides packet forwarding. An FCF switch maintains one routing table and one FIB table for each
VSAN.
Routing table contents
The routing table saves the routes discovered by various routing protocols. Routes in a routing table
include the following types:
• Direct routes—Routes discovered by link layer protocols
• Static routes—Routes manually configured by the administrator
• FSPF routes—Routes discovered by the Fabric Shortest Path First (FSPF) protocol
To display summary information about a routing table, use the display fc routing-table command as
follows:
display fc routing-table vsan 1
Routing Table: VSAN 1
Destinations : 6 Routes : 6
Destination/mask Protocol Preference Cost Interface
0x020000/8 FSPF 20 265 Vfc1
0x120000/8 STATIC 10 0 Vfc2
0xfffc01/24 DIRECT 0 0 InLoop0
0xfffffa/24 DIRECT 0 0 InLoop0
0xfffffc/24 DIRECT 0 0 InLoop0
0xfffffd/24 DIRECT 0 0 InLoop0
...
A route entry includes the following key items:
• Destination—Destination address of an FC frame.
• mask—Together with the destination address, specifies the destination node or the domain address
of an FCF switch. A logical AND operation between the destination address and the network mask
yields the domain address of the destination node or FCF switch. For example, if the destination
address is 0x010001 and the mask is 0xFF0000, the domain address of the destination node or
FCF switch is 0x010000. A network mask is made up of a certain number of consecutive 1s. It can
be expressed in hexadecimal format or by the number of 1s.