> # FCIP Links

> FCIP links consist of one or more TCP connections between two FCIP link endpoints. Each link carries encapsulated Fibre Channel frames.

> When the FCIP link comes up, the VE ports at both ends of the FCIP link create a virtual Fibre Channel (E)ISL and initiate the E port protocol to bring up the (E)ISL.

> By default, the FCIP feature on any Cisco MDS 9000 Family switch creates two TCP connections for each FCIP link:

> - One connection is used for data frames.
> - The other connection is used only for Fibre Channel control frames, that is, switch-to-switch protocol frames (all Class F). This arrangement provides low latency for all control frames.

> To enable FCIP on the IPS module or MPS-14/2 module, an FCIP profile and FCIP interface (interface FCIP) must be configured.

> The FCIP link is established between two peers, the VE port initialization behavior is identical to a normal E port. This behavior is independent of the link being FCIP or pure Fibre Channel, and is based on the E port discovery process (ELP, ESC).

> Once the FCIP link is established, the VE port behavior is identical to E port behavior for all inter-switch communication (including domain management, zones, and VSANs). At the Fibre Channel layer, all VE and E port operations are identical.

> When two FCIP link endpoints are created, an FCIP link is established between the two IPS modules or MPS-14/2 modules. To create an FCIP link, assign a profile to the FCIP interface and configure the peer information. The peer IP switch information initiates (creates) an FCIP link to that peer switch.

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