posted Dec 8, 2013, 11:52 AM by Rick McGee
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updated Dec 9, 2013, 5:43 PM
]
What is iSCSI - Internet Small Computer System Interface (iSCSI)
- Completely separate protocol stack form Fibre Channel
- Typically used in small to mid-range SAN's
- No dedicated SAN switches required
- No SAN switching knowledge required
- 1/10GE iSCI hardware offload cards available
iSCSI and the CCIE DC Test/Lab - iSCSI is not SAN switching
- End hosts run IP
- Storage Array runs just IP
- Transport is anything IP
- MDS can be used as an iSCSI to FC gateway
MDS and iSCSI - MDS is effectively a translational bridge for Fibre Channel and iSCSI
- Think bridging between Ethernet and Frame Relay in IOS
- How iSCSI gateway work
- FC Targets FLOGI as usual to Fibre Channel Fabric
- iSCI Initiators send Discovery to MDS
- Implies MDS has IP enabled Ethernet interfaces
- MDS applies Zoning/Access Lists
- iSCSI Initiator thinks FC target is iSCSI Target
- FC Target thinks iSCSI Initiator is FC Initiator
iSCSI Access Control - Like in FC, access control must be enforced
- Mounting someone else's volue can be catastrophic
- Access control can be enforced as:
- Zoning Based
- Norman WWPN, FCID, and Aliases, etc...
- Initiator's IP address
- Initiator's iSCSI qualified name (IQN)
- iSCSI Based Virtual Target
What s FCIP - Fibre Channel over IP (FCIP)
- SCSI over FCP over TCP over IP
- Same protocol stack as Fibre Channel
- Think IPv6 over IPv4 GRE tunnel
- Initiators and Targets are still Native Fibre Channel (of FCOE)
- Used for Fibre Channel SAN Extension
- Data replication over long distance
- Native Fibre Channel is sensitive to latency and drops
- TCP already has built in congestion management, retransmission, etc.
Here is a good diagram that shows the difference SAN protocol stack |
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