Fcip Circuit Failover Capabilities - Brocade Communications Systems 8 Administrator's Manual

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FCIP trunking
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FCIP circuit failover capabilities

Each FCIP circuit is assigned a metric, which is used in managing failover for FC traffic. Typically,
the metric will be either 0 or 1. If a circuit fails, FCIP Trunking tries first to retransmit any pending
send traffic over another lowest metric circuit. In
metric circuits. Circuit 1 has failed, and transmission fails over to circuit 2, which has the same
metric. Traffic that was pending at the time of failure is retransmitted over circuit 2. In order
delivery is ensured by the receiving 7800 switch.
FIGURE 5
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In a scenario where a FCIP tunnel has multiple circuits of different metrics, circuits with higher
metrics are treated as standby circuits, and are not used until all lower metric circuits fail.
Refer to "FCIP circuit failover capabilities"
An FCIP tunnel can have up to four circuits when using the 1GbE interfaces, They may be on
the same 1GbE interface or spread out over up to four 1GbE interfaces.
Committed bandwidth on both sides of the tunnels/circuits must be the same.
The maximum bandwidth for a single circuit is 1 Gbps. To utilize the entire bandwidth of an
XGE (10GbE) port, you must create ten 1 Gbps circuits within that interface.
When load leveling across multiple circuits, the difference between the committed rate of the
slowest circuit in the FCIP Trunk and the fastest circuit should be no greater than a factor of 4
(i.e. a 100 Mbps and a 400 Mbps circuit is OK, but a 10 Mbps and a 400 Mbps circuit is not
OK). This ensures that the entire bandwidth of the FCIP Trunk can be utilized. If you configure
circuits with the committed rates that different by more than a factor of 4, the entire bandwidth
of the FCIP Trunk may not be fully utilized.
A circuit defines source and destination IP addresses on either end of an FCIP tunnel.
If the circuit source and destination IP addresses are not on the same subnet, a IP static route
must be defined which designates the gateway IP address.
For IPv4 connections, multiple 1GbE or 10GbE ports on a FX8-24 blade or a 7800 switch
cannot be on same subnet. For IPv6 connections, each GbE (or 10GbE) port needs to be
connected to an interface that has a unique link local address. In other words multiple GbE
ports on a 7800 or FX8-24 cannot connect to next hops with the same link local address.
These restrictions will be removed in a later release.
7800
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Link loss and retransmission over peer lowest metric circuit
for a more detailed description.
Figure 5, circuit 1 and circuit 2 are both lowest
Circuit 1
X
Circuit 2
7800
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Fabric OS FCIP Administrator's Guide
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