Advertising Static iSCSI Targets

You can limit the Gigabit Ethernet interfaces through which static iSCSI targets are advertised. By default iSCSI targets are advertised on all Gigabit Ethernet interfaces, subinterfaces, port channel interfaces, and port channel subinterfaces.

Assigning the whole Fibre Channel target as an iSCSI virtual target

This example assigns the whole Fibre Channel target as an iSCSI virtual target. All LUNs that are part of the Fibre Channel target are available as part of the iSCSI target.

iscsi virtual-target name iqn.1987-02.com.cisco.target-1
pWWN 28:00:01:02:03:04:05:06

Mapping a subset of LUNs of a Fibre Channel target to three iSCSI virtual targets

This example maps a subset of LUNs of a Fibre Channel target to three iSCSI virtual targets. Each iSCSI target only has one LUN.

iscsi virtual-target name iqn.1987-02.com.cisco.target-1
pWWN 28:00:01:02:03:04:05:06 fc-lun 0 iscsi-lun 0
iscsi virtual-target name iqn.1987-02.com.cisco.target-2
pWWN 28:00:01:02:03:04:05:06 fc-lun 1 iscsi-lun 0
iscsi virtual-target name iqn.1987-02.com.cisco.target-3
pWWN 28:00:01:02:03:04:05:06 fc-lun 2 iscsi-lun 0

Mapping three subsets of Fibre Channel LUN targets to three iSCSI virtual targets

This example maps three subsets of Fibre Channel LUN targets to three iSCSI virtual targets. Two iSCSI targets have one LUN and the third iSCSI target has two LUNs.

iscsi virtual-target name iqn.1987-02.com.cisco.target-1
pWWN 28:00:01:02:03:04:05:06 fc-lun 0 iscsi-lun 0
iscsi virtual-target name iqn.1987-02.com.cisco.target-2
pWWN 28:00:01:02:03:04:05:06 fc-lun 1 iscsi-lun 0
iscsi virtual-target name iqn.1987-02.com.cisco.target-3
pWWN 28:00:01:02:03:04:05:06 fc-lun 2 iscsi-lun 0
pWWN 28:00:01:02:03:04:05:06 fc-lun 3 iscsi-lun 1

Transparent Initiator Mode

Each iSCSI host is presented as one virtual Fibre Channel host (that is, one Fibre Channel N port). The benefit of transparent mode is it allows a finer-level of Fibre Channel access control configuration. Because of the one-to-one mapping from iSCSI to Fibre Channel, each host can have different zoning or LUN access control on the Fibre Channel storage device.

When an iSCSI host connects to the Fibre Channel module with IPS ports or MPS-14/2 module, a virtual host N port (HBA port) is created for the host (see the below figure). Every Fibre Channel N port requires a unique Node WWN and Port WWN.

After the virtual N port is created with the WWNs, a fabric login (FLOGI) is done through the virtual iSCSI interface of the IPS port. After the FLOGI is completed, the virtual N port is online in the Fibre Channel SAN and virtual N port is registered in the Fibre Channel name server. The Fibre Channel module with IPS ports or MPS-14/2 module registers the following entries in the Fibre Channel name server:

• IP address of the iSCSI host in the IP-address field on the name server

• IQN of the iSCSI host in the symbolic-node-name field of the name server

• SCSI_FCP in the FC-4 type field of the name server

• Initiator flag in the FC-4 feature of the name server

• Vendor-specific iSCSI GW flag in the FC-4 type field to identify the N-port device as an iSCSI gateway device in the name server.

When all the iSCSI sessions from the iSCSI host are terminated, the Fibre Channel module with IPS ports or MPS-14/2 modules perform an explicit Fabric logout (FLOGO) to remove the virtual N-port device from the Fibre Channel SAN (this indirectly de-registers the device from the Fibre Channel name server).

For every iSCSI session from the host to the iSCSI virtual target there is a corresponding Fibre Channel session to the real Fibre Channel target. There are three iSCSI hosts, and all three of them connect to the same Fibre Channel target. There is one Fibre Channel session from each of the three virtual Fibre Channel hosts to the target.

iSCSI Initiator Idle Timeout

iSCSI initiator idle timeout specifies the time for which the virtual Fibre Channel N port is kept idle after the initiator logs out from its last iSCSI session. The default value for this timer is 300 seconds. This is useful to avoid N ports logging in to and logging off of the Fibre Channel SAN as transient failure occurs in the IP network. This helps reduce unnecessary RSCNs being generated in the Fibre Channel SAN.

Dynamic Mapping

With dynamic mapping, an iSCSI host is mapped to a dynamically generated port WWN (pWWN) and node WWN (nWWN). Each time the iSCSI host connects it might be mapped to a different WWN. Use this option if no access control is required on the Fibre Channel target device (because the target device access control is usually configured using the host WWN).

The WWNs are allocated from the MDS switch's WWN pool. The WWN mapping to the iSCSI host is maintained as long as the iSCSI host has at least one iSCSI session to the IPS port. When all iSCSI sessions from the host are terminated and the Fibre Channel module with IPS ports or MPS-14/2 module performs an FLOGO for the virtual N port of the host, the WWNs are released back to the switch's Fibre Channel WWN pool. These addresses are then available for assignment to other iSCSI hosts requiring access to the Fibre Channel Fabric.

The following are three dynamic initiator modes are supported:

• iSCSI—Dynamic initiators are treated as iSCSI initiators and can access dynamic virtual targets and configured iSCSI virtual targets.

• iSLB—Dynamic initiators are treated as iSLB initiators.

• Deny—Dynamic initiators are not allowed to log in to the MDS switch.

iSCSI dynamic mapping is the default mode of operation. This configuration is distributed using CFS

Static Mapping

With static mapping, an iSCSI host is mapped to a specific pWWN and nWWN. This mapping is maintained in persistent storage and each time the iSCSI host connects, the same WWN mapping is used. This mode is required if you use access control on the target device.

You can implement static mapping in one of two ways:

• User assignment: You can specify your own unique WWN by providing them during the configuration process.

• System assignment: You can request that the switch provide a WWN from the switch’s Fibre Channel WWN pool and keep the mapping in its configuration.

We recommend using the system-assign option. If you manually assign a WWN, you must ensure its uniqueness (see the Cisco Fabric Manager Fabric Configuration Guide and Cisco MDS 9000 Family NX-OS Fabric Configuration Guide for more information). You should not use any previously assigned WWNs.

Making the Dynamic iSCSI Initiator WWN Mapping Static

After a dynamic iSCSI initiator has already logged in, you may decide to permanently keep the automatically assigned nWWN/pWWN mapping so this initiator uses the same mapping the next time it logs in.

You can convert a dynamic iSCSI initiator to static iSCSI initiator and make its WWNs persistent.

Note	You cannot convert a dynamic iSCSI initiator to a static iSLB initiator or a dynamic iSLB initiator to a static iSCSI initiator.

Note	Making the dynamic pWWNs static after the initiator is created is supported only through the CLI, not through Device Manager or Fabric Manager. In Fabric Manager or Device Manager, you must delete and then recreate this initiator to have the pWWNs static.

Checking for WWN Conflicts

WWNs assigned to static iSCSI initiators by the system can be inadvertently returned to the system when an upgrade fails or you downgrade the system software (manually booting up an older Cisco MDS SAN-OS release without using the install all command). In these instances, the system can later assign those WWNs to other iSCSI initiators (dynamic or static) and cause conflicts.

You can address this problem by checking for and removing any configured WWNs that belong to the system whenever such scenarios occur.

iSCSI Interface Advanced Features

Advanced configuration options are available for iSCSI interfaces on a per-IPS port basis. These configurations are similar to the advanced FCIP configurations and are already explained in that section (see Advanced FCIP Profile Configuration for more information).

	
switch# config terminal
switch(config)# interface iscsi 4/1
switch(config-if)#

iSCSI Listener Port

You can configure the TCP port number for the iSCSI interface that listens for new TCP connections. The default port number is 3260. Once you change the TCP port number, the iSCSI port only accepts TCP connections on the newly configured port.

TCP Tuning Parameters

You can configure the following TCP parameters:

• Minimum retransmit timeout (See the Minimum Retransmit Timeout for more information).

• Keepalive timeout (See the Keepalive Timeout section for more information).

• Maximum retransmissions (See the Maximum Retransmissions section for more information).

• Path MTU (See the Path MTUs section for more information).

• SACK (SACK is enabled by default for iSCSI TCP configurations).

• Window management (The iSCSI defaults are max-bandwidth is 1 Gbps, min-available-bandwidth is 70 Mbps, and round-trip-time is 1 msec). (See the Window Management section for more information).

• Buffer size (The iSCSI default send buffer size is 4096 KB) (See the Displaying FCIP Profile Information section for more information).

• Window congestion monitoring (enabled by default and the default burst size is 50 KB) (See the Monitoring Congestion section for more information).

• Maximum delay jitter (enabled by default and the default time is 500 microseconds).

iSCSI Routing Modes

Cisco MDS 9000 Family switches support multiple iSCSI routing modes. Each mode negotiates different operational parameters, has different advantages and disadvantages, and is suitable for different usages.

• Pass-thru mode: In pass-thru mode, the port on the Fibre Channel module with IPS ports or MPS 14/2 module converts and forwards read data frames from the Fibre Channel target to the iSCSI host frame-by-frame without buffering. This means that one data-in frame received is immediately sent out as one iSCSI data-in PDU.

  In the opposite direction, the port on the Fibre Channel module with IPS ports or MPS 14/2 module limits the maximum size of iSCSI write data-out PDU that the iSCSI host can send to the maximum data size that the Fibre Channel target specifies that it can receive. The result is one iSCSI data-out PDU received sent out as one Fibre Channel data frame to the Fibre Channel target.

  The absence of buffering in both directions leads to an advantage of lower forwarding latency. However, a small maximum data segment length usually results in lower data transfer performance from the host because of a higher processing overhead by the host system. Another benefit of this mode is iSCSI data digest can be enabled. This helps protect the integrity of iSCSI data carried in the PDU over what TCP checksum offers.

• Store-and-forward mode (default): In store-and-forward mode, the port on the Fibre Channel module with IPS ports or MPS 14/2 module assembles all the Fibre Channel data frames of an exchange to build one large iSCSI data-in PDU before forwarding it to the iSCSI client.

  In the opposite direction, the port on the Fibre Channel module with IPS ports or MPS 14/2 module does not impose a small data segment size on the host so the iSCSI host can send an iSCSI data-out PDU of any size (up to 256 KB). The port then waits until the whole iSCSI data-out PDU is received before it converts, or splits, the PDU, and forwards Fibre Channel frames to the Fibre Channel target.

  The advantage of this mode is higher data transfer performance from the host. The disadvantages are higher transfer latency and that the iSCSI data digest (CRC) cannot be used.

  Note	The store-and-forward mode is the default forwarding mode.

• Cut-through mode: Cut-through mode improves the read operation performance over store-and-forward mode. The port on the Fibre Channel module with IPS ports or MPS 14/2 module achieves this by forwarding each Fibre Channel data-in frame to the iSCSI host as it is received without waiting for the whole exchange complete. There is no difference for write data-out operations from store-and-forward mode.

Note	Changing the forwarding mode of an iSCSI interface that is part of an iSLB VRRP group impacts load balancing on the interface. See the Changing iSCSI Interface Parameters and the Impact on Load Balancing section.

Displaying iSCSI Interfaces

Use the show iscsi interface command to view the summary, counter, description, and status of the iSCSI interface. Use the output to verify the administrative mode, the interface status, TCP parameters currently used, and brief statistics.

Example of Displaying the iSCSI Interface Information:

switch# show interface iscsi 4/1 
iscsi4/1 is up
Hardware is GigabitEthernet
Port WWN is 20:cf:00:0c:85:90:3e:80
Admin port mode is ISCSI
Port mode is ISCSI
Speed is 1 Gbps
iSCSI initiator is identified by name
Number of iSCSI session: 0 (discovery session: 0)
Number of TCP connection: 0
Configured TCP parameters
Local Port is 3260
PMTU discover is enabled, reset timeout is 3600 sec
Keepalive-timeout is 60 sec
Minimum-retransmit-time is 300 ms
Max-retransmissions 4
Sack is enabled
QOS code point is 0
Maximum allowed bandwidth is 1000000 kbps
Minimum available bandwidth is 70000 kbps
Estimated round trip time is 1000 usec
Send buffer size is 4096 KB
Congestion window monitoring is enabled, burst size is 50 KB
Configured maximum jitter is 500 us
Forwarding mode: store-and-forward
TMF Queueing Mode : disabled
Proxy Initiator Mode : disabled
5 minutes input rate 0 bits/sec, 0 bytes/sec, 0 frames/sec
5 minutes output rate 0 bits/sec, 0 bytes/sec, 0 frames/sec
iSCSI statistics
Input 0 packets, 0 bytes
Command 0 pdus, Data-out 0 pdus, 0 bytes
Output 0 packets, 0 bytes
Response 0 pdus (with sense 0), R2T 0 pdus
Data-in 0 pdus, 0 bytes

Displaying iSCSI Statistic

Use the show iscsi stats command to view brief or detailed iSCSI statistics per iSCSI interface. For more information, see the following examples.

The following example displays iSCSI throughput on an IPS port in both inbound and outbound directions. It also displays the number of different types of iSCSI PDU received and transmitted by this IPS port

Example of Displaying Brief iSCSI Statistics for an iSCSI Interface:

switch# show iscsi stats iscsi 2/1
iscsi2/1
5 minutes input rate 704 bits/sec, 88 bytes/sec, 1 frames/sec
5 minutes output rate 704 bits/sec, 88 bytes/sec, 1 frames/sec
iSCSI statistics
974756 packets input, 142671620 bytes
Command 2352 pdus, Data-out 44198 pdus, 92364800 bytes, 0 fragments, unsolicited 0 bytes
output 1022920 packets, 143446248 bytes
Response 2352 pdus (with sense 266), R2T 1804 pdus
Data-in 90453 pdus, 92458248 bytes

The following example displays detailed iSCSI statistics for an IPS port. Along with the traffic rate and the number of each iSCSI PDU type, it shows the number of FCP frames received and forwarded, the number of iSCSI login attempts, successes, and failures. It also shows the number of different types of iSCSI PDUs sent and received that are noncritical or occur less frequently, such as NOP in and out (NOP-In and NOP-Out), text request and response (Text-REQ and Text-RESP), and task management request and response (TMF-REQ and TMF-RESP).

Various types of errors and PDU or frame drop occurrences are also counted and displayed. For example, Bad header digest shows the number of iSCSI PDUs received that have a header digest that fails CRC verification. The iSCSI Drop section shows the number of PDUs that were dropped because of reasons such as target down, LUN mapping fail, Data CRC error, or unexpected Immediate or Unsolicited data. These statistics are helpful for debugging purposes when the feature is not working as expected.

The last section, Buffer Stats, gives statistics on the internal IPS packet buffer operation. This section is for debugging purposes only.

Example of displaying detailed iSCSI statistics for the iSCSI interface:

switch# show iscsi stats iscsi 2/1 detail
iscsi2/1
5 minutes input rate 704 bits/sec, 88 bytes/sec, 1 frames/sec
5 minutes output rate 704 bits/sec, 88 bytes/sec, 1 frames/sec
iSCSI statistics
974454 packets input, 142656516 bytes
Command 2352 pdus, Data-out 44198 pdus, 92364800 bytes, 0 fragments, unsolicited 0 bytes
output 1022618 packets, 143431144 bytes
Response 2352 pdus (with sense 266), R2T 1804 pdus
Data-in 90453 pdus, 92458248 bytes
iSCSI Forward:
Command:2352 PDUs (Rcvd:2352)
Data-Out (Write):16236 PDUs (Rcvd 44198), 0 fragments, 92364800 bytes, unsolicited 0 bytes
FCP Forward:
Xfer_rdy:1804 (Rcvd:1804)
Data-In:90453 (Rcvd:90463), 92458248 bytes
Response:2352 (Rcvd:2362), with sense 266
TMF Resp:0
 
iSCSI Stats:
Login:attempt:13039, succeed:110, fail:12918, authen fail:0
Rcvd:NOP-Out:914582, Sent:NOP-In:914582
NOP-In:0, Sent:NOP-Out:0
TMF-REQ:0, Sent:TMF-RESP:0
Text-REQ:18, Sent:Text-RESP:27
SNACK:0
Unrecognized Opcode:0, Bad header digest:0
Command in window but not next:0, exceed wait queue limit:0
Received PDU in wrong phase:0
SCSI Busy responses:0
Immediate data failure::Separation:0
Unsolicited data failure::Separation:0, Segment:0
Add header:0
Sequence ID allocation failure:0
FCP Stats:
Total:Sent:47654
Received:96625 (Error:0, Unknown:0)
Sent:PLOGI:10, Rcvd:PLOGI_ACC:10, PLOGI_RJT:0
PRLI:10, Rcvd:PRLI_ACC:10, PRLI_RJT:0, Error:0, From initiator:0
LOGO:4, Rcvd:LOGO_ACC:0, LOGO_RJT:0
PRLO:4, Rcvd:PRLO_ACC:0, PRLO_RJT:0
ABTS:0, Rcvd:ABTS_ACC:0
TMF REQ:0
Self orig command:10, Rcvd:data:10, resp:10
Rcvd:PLOGI:156, Sent:PLOGI_ACC:0, PLOGI_RJT:156
LOGO:0, Sent:LOGO_ACC:0, LOGO_RJT:0
PRLI:8, Sent:PRLI_ACC:8, PRLI_RJT:0
PRLO:0, Sent:PRLO_ACC:0, PRLO_RJT:0
ADISC:0, Sent:ADISC_ACC:0, ADISC_RJT:0
ABTS:0
 
iSCSI Drop:
Command:Target down 0, Task in progress 0, LUN map fail 0
CmdSeqNo not in window 0, No Exchange ID 0, Reject 0
No task:0
Data-Out:0, Data CRC Error:0
TMF-Req:0, No task:0
Unsolicited data:0, Immediate command PDU:0
FCP Drop:
Xfer_rdy:0, Data-In:0, Response:0
 
Buffer Stats:
Buffer less than header size:0, Partial:45231, Split:322
Pullup give new buf:0, Out of contiguous buf:0, Unaligned m_data:0

Displaying Proxy Initiator Information

If the proxy initiator feature is enabled in the iSCSI interface, use the show interface iscsi command to display configured proxy initiator information.

Example of displaying proxy initiator information for the iSCSI interface with system-sssigned WWNs:

switch# show interface iscsi 4/1
iscsi4/1 is up
Hardware is GigabitEthernet
Port WWN is 20:c1:00:05:30:00:a7:9e
Admin port mode is ISCSI
Port mode is ISCSI
Speed is 1 Gbps
iSCSI initiator is identified by name
Number of iSCSI session: 0, Number of TCP connection: 0
Configured TCP parameters
Local Port is 3260
PMTU discover is enabled, reset timeout is 3600 sec
Keepalive-timeout is 60 sec
Minimum-retransmit-time is 300 ms
Max-retransmissions 4
Sack is disabled
QOS code point is 0
Forwarding mode: pass-thru
TMF Queueing Mode : disabled
Proxy Initiator Mode : enabled<----------------------------Proxy initiator is enabled
nWWN is 28:00:00:05:30:00:a7:a1 (system-assigned)<----System-assigned nWWN
pWWN is 28:01:00:05:30:00:a7:a1 (system-assigned)<---- System-assigned pWWN
5 minutes input rate 0 bits/sec, 0 bytes/sec, 0 frames/sec
5 minutes output rate 0 bits/sec, 0 bytes/sec, 0 frames/sec
iSCSI statistics
Input 7 packets, 2912 bytes
Command 0 pdus, Data-out 0 pdus, 0 bytes
Output 7 packets, 336 bytes
Response 0 pdus (with sense 0), R2T 0 pdus
Data-in 0 pdus, 0 bytes

Example of displaying proxy initiator information for the iSCSI interface with user-assigned WWNs:

switch# show interface iscsi 4/2
iscsi4/2 is up
Hardware is GigabitEthernet
Port WWN is 20:c1:00:05:30:00:a7:9e
Admin port mode is ISCSI
Port mode is ISCSI
Speed is 1 Gbps
iSCSI initiator is identified by name
Number of iSCSI session: 0, Number of TCP connection: 0
Configured TCP parameters
Local Port is 3260
PMTU discover is enabled, reset timeout is 3600 sec
Keepalive-timeout is 60 sec
Minimum-retransmit-time is 300 ms
Max-retransmissions 4
Sack is disabled
QOS code point is 0
Forwarding mode: pass-thru
TMF Queueing Mode : disabled
Proxy Initiator Mode : enabled
nWWN is 11:11:11:11:11:11:11:11 (manually-configured)<----User-assigned nWWN
pWWN is 22:22:22:22:22:22:22:22 (manually-configured)<----User-assigned pWWN
5 minutes input rate 0 bits/sec, 0 bytes/sec, 0 frames/sec
5 minutes output rate 0 bits/sec, 0 bytes/sec, 0 frames/sec
iSCSI statistics
Input 7 packets, 2912 bytes
Command 0 pdus, Data-out 0 pdus, 0 bytes
Output 7 packets, 336 bytes
Response 0 pdus (with sense 0), R2T 0 pdus
Data-in 0 pdus, 0 bytes

Displaying Global iSCSI Information

Use the show iscsi global command to view the overall configuration and the iSCSI status.

Example of displaying the current global iSCSI configuration and state:

switch# show iscsi global
iSCSI Global information
Authentication: CHAP, NONE
Import FC Target: Enabled
Initiator idle timeout: 300 seconds
Number of target node: 0
Number of portals: 11
Number of session: 0
Failed session: 0, Last failed initiator name:

Displaying iSCSI Sessions

Use the show iscsi session command to view details about the current iSCSI sessions in the switch. Without parameters, this command displays all sessions. The output can be filtered by specifying an initiator, a target, or both. The following example shows one iSCSI initiator configured based on the IQN (iqn.1987-05.com.cisco:02.3021b0f2fda0.avanti12-w2k) and another based on its IPv4 address (10.10.100.199).

Example of Displaying Brief Information of All iSCSI Sessions:

switch# show iscsi session 
Initiator iqn.1987-05.com.cisco:02.3021b0f2fda0.avanti12-w2k
Initiator ip addr (s): 10.10.100.116
Session #1
Discovery session, ISID 00023d000043, Status active
Session #2
Target VT1
VSAN 1, ISID 00023d000046, Status active, no reservation
Session #3
Target VT2
VSAN 1, ISID 00023d000048, Status active, no reservation 
Initiator 10.10.100.199
Initiator name iqn.1987-05.com.cisco.01.7e3183ae458a94b1cd6bc168cba09d2e
Session #1
Target VT2
VSAN 1, ISID 246700000000, Status active, no reservation 
Session #2
Target VT1
VSAN 1, ISID 246b00000000, Status active, no reservation 
Session #3
Target iqn.1987-05.com.cisco:05.switch.04-01.2100002037a6be32
VSAN 1, ISID 246e00000000, Status active, no reservation

The following example display the iSCSI initiator configured based on its IPv4 address (10.10.100.199).

Eample of displaying brief information about the specified iSCSI session:

switch# show iscsi session initiator 10.10.100.199 target VT1
Initiator 10.10.100.199
Initiator name iqn.1987-05.com.cisco.01.7e3183ae458a94b1cd6bc168cba09d2e
Session #1
Target VT1
VSAN 1, ISID 246b00000000, Status active, no reservation

Example of displaying detailed information about the specified iSCSI session:

switch# show iscsi session initiator 10.10.100.199 target VT1 detail
Initiator 10.10.100.199 (oasis-qa)
Initiator name iqn.1987-05.com.cisco.01.7e3183ae458a94b1cd6bc168cba09d2e
Session #1 (index 3)
Target VT1
VSAN 1, ISID 246b00000000, TSIH 384, Status active, no reservation
Type Normal, ExpCmdSN 39, MaxCmdSN 54, Barrier 0
MaxBurstSize 0, MaxConn 0, DataPDUInOrder No
DataSeqInOrder No, InitialR2T Yes, ImmediateData No
Registered LUN 0, Mapped LUN 0
Stats:
PDU: Command: 38, Response: 38
Bytes: TX: 8712, RX: 0
Number of connection: 1
Connection #1
Local IP address: 10.10.100.200, Peer IP address: 10.10.100.199
CID 0, State: LOGGED_IN
StatSN 62, ExpStatSN 0
MaxRecvDSLength 1024, our_MaxRecvDSLength 1392
CSG 3, NSG 3, min_pdu_size 48 (w/ data 48)
AuthMethod none, HeaderDigest None (len 0), DataDigest None (len 0)
Version Min: 2, Max: 2
FC target: Up, Reorder PDU: No, Marker send: No (int 0)
Received MaxRecvDSLen key: No

Displaying iSCSI Initiators

Use the show iscsi initiator command to display information about all initiators connected to an iSCSI interface in the switch. The information can be filtered to display only the desired iSCSI initiator by specifying the initiator name. Detailed output of the iSCSI initiator can be obtained by specifying the detail option. The iscsi-session (and optionally detail ) parameter displays only iSCSI session information. The fcp-session (and optionally detail ) parameter displays only FCP session information. The output includes static and dynamic initiators.

Example of displaying information about connected iSCSI initiators:

switch# show iscsi initiator
iSCSI Node name is iqn.1987-05.com.cisco:02.3021b0f2fda0.avanti12-w2k
Initiator ip addr (s): 10.10.100.116
iSCSI alias name: AVANTI12-W2K
Node WWN is 22:01:00:05:30:00:10:e1 (configured)
Member of vsans: 1, 2, 10
Number of Virtual n_ports: 1
Virtual Port WWN is 22:04:00:05:30:00:10:e1 (configured)
Interface iSCSI 4/1, Portal group tag: 0x180
VSAN ID 1, FCID 0x6c0202
VSAN ID 2, FCID 0x6e0000
VSAN ID 10, FCID 0x790000
 
iSCSI Node name is 10.10.100.199
iSCSI Initiator name: iqn.1987-05.com.cisco.01.7e3183ae458a94b1cd6bc168cba09d2e
iSCSI alias name: oasis-qa
Node WWN is 22:03:00:05:30:00:10:e1 (configured)
Member of vsans: 1, 5
Number of Virtual n_ports: 1
Virtual Port WWN is 22:00:00:05:30:00:10:e1 (configured)
Interface iSCSI 4/1, Portal group tag: 0x180
VSAN ID 5, FCID 0x640000
VSAN ID 1, FCID 0x6c0203

Example of displaying detailed information about the iSCSI initiator:

switch# show iscsi initiator iqn.1987-05.com.cisco:02.3021b0f2fda0.avanti12-w2k detail
iSCSI Node name is iqn.1987-05.com.cisco:02.3021b0f2fda0.avanti12-w2k
Initiator ip addr (s): 10.10.100.116
iSCSI alias name: AVANTI12-W2K
Node WWN is 22:01:00:05:30:00:10:e1 (configured)
Member of vsans: 1, 2, 10
Number of Virtual n_ports: 1
 
Virtual Port WWN is 22:04:00:05:30:00:10:e1 (configured)
Interface iSCSI 4/1, Portal group tag is 0x180
VSAN ID 1, FCID 0x6c0202
1 FC sessions, 1 iSCSI sessions
iSCSI session details <-------------------iSCSI session details
Target: VT1
Statistics:
PDU: Command: 0, Response: 0
Bytes: TX: 0, RX: 0
Number of connection: 1
TCP parameters
Local 10.10.100.200:3260, Remote 10.10.100.116:4190
Path MTU: 1500 bytes
Retransmission timeout: 310 ms
Round trip time: Smoothed 160 ms, Variance: 38
Advertized window: Current: 61 KB, Maximum: 62 KB, Scale: 0
Peer receive window: Current: 63 KB, Maximum: 63 KB, Scale: 0
Congestion window: Current: 1 KB
 
FCP Session details <-------------------FCP session details
Target FCID: 0x6c01e8 (S_ID of this session: 0x6c0202)
pWWN: 21:00:00:20:37:62:c0:0c, nWWN: 20:00:00:20:37:62:c0:0c
Session state: CLEANUP
1 iSCSI sessions share this FC session
Target: VT1
Negotiated parameters
RcvDataFieldSize 1392 our_RcvDataFieldSize 1392
MaxBurstSize 0, EMPD: FALSE
Random Relative Offset: FALSE, Sequence-in-order: Yes
Statistics:
PDU: Command: 0, Response: 0

Use the show fcns database command (and optionally detail ) to display the Fibre Channel name server entry for the Fibre Channel N port created for iSCSI initiators in the SAN.

Example of displaying the FCNS database contents:

switch# show fcns database
VSAN 1:
--------------------------------------------------------------------------
FCID TYPE PWWN (VENDOR) FC4-TYPE:FEATURE
--------------------------------------------------------------------------
0x020101 N 22:04:00:05:30:00:35:e1 (Cisco) scsi-fcp:init isc..w <--iSCSI
0x020102 N 22:02:00:05:30:00:35:e1 (Cisco) scsi-fcp:init isc..w initiator
0x0205d4 NL 21:00:00:04:cf:da:fe:c6 (Seagate) scsi-fcp:target
0x0205d5 NL 21:00:00:04:cf:e6:e4:4b (Seagate) scsi-fcp:target
...
Total number of entries = 10
 
VSAN 2:
--------------------------------------------------------------------------
FCID TYPE PWWN (VENDOR) FC4-TYPE:FEATURE
--------------------------------------------------------------------------
0xef0001 N 22:02:00:05:30:00:35:e1 (Cisco) scsi-fcp:init isc..w
Total number of entries = 1
 
VSAN 3:
--------------------------------------------------------------------------
FCID TYPE PWWN (VENDOR) FC4-TYPE:FEATURE
--------------------------------------------------------------------------
0xed0001 N 22:02:00:05:30:00:35:e1 (Cisco) scsi-fcp:init isc..w
Total number of entries = 1
 

Example of displaying the FCNS database in detail:

switch# show fcns database detail
------------------------
VSAN:1 FCID:0x020101
------------------------
port-wwn (vendor) :22:04:00:05:30:00:35:e1 (Cisco)
node-wwn :22:03:00:05:30:00:35:e1
class :2,3
node-ip-addr :10.2.2.12 <--- iSCSI initiator's IPv4 address
ipa :ff ff ff ff ff ff ff ff
fc4-types:fc4_features:scsi-fcp:init iscsi-gw
symbolic-port-name :
symbolic-node-name :iqn.1991-05.com.microsoft:oasis2-dell <--- iSCSI initiator's IQN
port-type :N
port-ip-addr :0.0.0.0
fabric-port-wwn :22:01:00:05:30:00:35:de
hard-addr :0x000000
------------------------
VSAN:1 FCID:0x020102
------------------------
port-wwn (vendor) :22:02:00:05:30:00:35:e1 (Cisco)
node-wwn :22:01:00:05:30:00:35:e1
class :2,3
node-ip-addr :10.2.2.11
ipa :ff ff ff ff ff ff ff ff
fc4-types:fc4_features:scsi-fcp:init iscsi-gw
symbolic-port-name :
symbolic-node-name :iqn.1987-05.com.cisco.01.14ac33ba567f986f174723b5f9f2377
port-type :N
port-ip-addr :0.0.0.0
fabric-port-wwn :22:01:00:05:30:00:35:de
hard-addr :0x000000
...
Total number of entries = 10
======================================================================
------------------------
VSAN:2 FCID:0xef0001
------------------------
port-wwn (vendor) :22:02:00:05:30:00:35:e1 (Cisco)
node-wwn :22:01:00:05:30:00:35:e1
class :2,3
node-ip-addr :10.2.2.11
ipa :ff ff ff ff ff ff ff ff
fc4-types:fc4_features:scsi-fcp:init iscsi-gw
symbolic-port-name :
symbolic-node-name :iqn.1987-05.com.cisco.01.14ac33ba567f986f174723b5f9f2377
port-type :N
port-ip-addr :0.0.0.0
fabric-port-wwn :22:01:00:05:30:00:35:de
hard-addr :0x000000
Total number of entries = 1
...

Use the show iscsi initiator configured command to display information about all the configured iSCSI initiators. Specifying the name shows information about the desired initiator.

Example of displaying information about configured initiators:

switch# show iscsi initiator configured
iSCSI Node name is iqn.1987-05.com.cisco:02.3021b0f2fda0.avanti12-w2k
Member of vsans: 1, 2, 10
Node WWN is 22:01:00:05:30:00:10:e1
No. of PWWN: 5
Port WWN is 22:04:00:05:30:00:10:e1
Port WWN is 22:05:00:05:30:00:10:e1
Port WWN is 22:06:00:05:30:00:10:e1
Port WWN is 22:07:00:05:30:00:10:e1
Port WWN is 22:08:00:05:30:00:10:e1
 
iSCSI Node name is 10.10.100.199
Member of vsans: 1, 5
Node WWN is 22:03:00:05:30:00:10:e1
No. of PWWN: 4
Port WWN is 22:00:00:05:30:00:10:e1
Port WWN is 22:09:00:05:30:00:10:e1
Port WWN is 22:0a:00:05:30:00:10:e1
Port WWN is 22:0b:00:05:30:00:10:e1
 
User Name for Mutual CHAP: testuser

Displaying iSCSI Virtual Targets

Use the show iscsi virtual-target command to display information about the Fibre Channel targets exported as iSCSI virtual targets to the iSCSI initiators. The output includes static as well as dynamic targets.

Example of displaying exported targets:

switch# show iscsi virtual-target
target: VT1
* Port WWN 21:00:00:20:37:62:c0:0c
Configured node
all initiator permit is enabled
target: VT2
Port WWN 21:00:00:04:cf:4c:52:c1
Configured node
all initiator permit is disabled
target: iqn.1987-05.com.cisco:05.switch.04-01.2100002037a6be32
Port WWN 21:00:00:20:37:a6:be:32 , VSAN 1
Auto-created node

Displaying iSCSI User Information

The show user-account iscsi command displays all configured iSCSI user names.

Example of displaying iSCSI user names:

switch# show user-account iscsi
username:iscsiuser
secret: dsfffsffsffasffsdffg
username:user2
secret:cshadhdhsadadjajdjas

Load distribution with the Default Metric

switch# show islb vrrp summary
.
.
.
--------------------------------------------------------------------------------
VR Id VRRP IP Switch WWN Ifindex Load
--------------------------------------------------------------------------------
M 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/1.441 0
1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441 1000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441 1000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441 1000
-- Initiator To Interface Assignment --
--------------------------------------------------------------------------------
Initiator VR Id VRRP IP Switch WWN Ifindex
--------------------------------------------------------------------------------
iqn.cisco.test-linux.init0 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441
iqn.cisco.test-linux.init1 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441
iqn.cisco.test-linux.init 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441

switch# show islb vrrp summary
.
.
.
--------------------------------------------------------------------------------
VVR Id VRRP IP Switch WWN Ifindex Load
--------------------------------------------------------------------------------
M 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/1.441 1000
1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441 1000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441 1000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441 1000
-- Initiator To Interface Assignment --
--------------------------------------------------------------------------------
Initiator VR Id VRRP IP Switch WWN Ifindex
--------------------------------------------------------------------------------
iqn.cisco.test-linux.init0 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441
iqn.cisco.test-linux.init1 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441
iqn.cisco.test-linux.init2 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441
iqn.cisco.test-linux.init3 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/1.441

switch# show islb vrrp summary
.
.
.
--------------------------------------------------------------------------------
VVR Id VRRP IP Switch WWN Ifindex Load
--------------------------------------------------------------------------------
M 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/1.441 1000
1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441 3000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441 3000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441 2000
-- Initiator To Interface Assignment --
--------------------------------------------------------------------------------
Initiator VR Id VRRP IP Switch WWN Ifindex
--------------------------------------------------------------------------------
iqn.cisco.test-linux.init0 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441
iqn.cisco.test-linux.init1 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441
iqn.cisco.test-linux.init2 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441
iqn.cisco.test-linux.init3 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/1.441
iqn.cisco.test-linux.init4 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441
iqn.cisco.test-linux.init5 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441
iqn.cisco.test-linux.init6 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441
iqn.cisco.test-linux.init7 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441
iqn.cisco.test-linux.init8 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441

Load Distribution with the Metric Set to 3000 on One Initiator

switch# show islb vrrp summary
.
.
.
--------------------------------------------------------------------------------
VVR Id VRRP IP Switch WWN Ifindex Load
--------------------------------------------------------------------------------
M 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/1.441 0
1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441 1000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441 3000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441 1000
-- Initiator To Interface Assignment --
--------------------------------------------------------------------------------
Initiator VR Id VRRP IP Switch WWN Ifindex
--------------------------------------------------------------------------------
iqn.cisco.test-linux.init0 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441
iqn.cisco.test-linux.init1 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441
iqn.cisco.test-linux.init2 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441

switch# show islb vrrp summary
.
.
.
--------------------------------------------------------------------------------
VVR Id VRRP IP Switch WWN Ifindex Load
--------------------------------------------------------------------------------
M 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/1.441 1000
1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441 3000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441 1000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441 1000
-- Initiator To Interface Assignment --
--------------------------------------------------------------------------------
Initiator VR Id VRRP IP Switch WWN Ifindex
--------------------------------------------------------------------------------
iqn.cisco.test-linux.init0 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441
iqn.cisco.test-linux.init1 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441
iqn.cisco.test-linux.init2 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441
iqn.cisco.test-linux.init3 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/1.441

switch# show islb vrrp summary
.
.
.
--------------------------------------------------------------------------------
VVR Id VRRP IP Switch WWN Ifindex Load
--------------------------------------------------------------------------------
M 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/1.441 2000
1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441 3000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441 3000
1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441 3000
-- Initiator To Interface Assignment --
--------------------------------------------------------------------------------
Initiator VR Id VRRP IP Switch WWN Ifindex
--------------------------------------------------------------------------------
iqn.cisco.test-linux.init0 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/2.441
iqn.cisco.test-linux.init1 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441
iqn.cisco.test-linux.init2 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441
iqn.cisco.test-linux.init3 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/1.441
iqn.cisco.test-linux.init4 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441
iqn.cisco.test-linux.init5 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441
iqn.cisco.test-linux.init6 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/1.441
iqn.cisco.test-linux.init7 1 10.10.122.115 20:00:00:0c:ce:5c:5b:c0 GigabitEthernet1/2.441
iqn.cisco.test-linux.init8 1 10.10.122.115 20:00:00:0b:5f:3c:01:80 GigabitEthernet2/1.441

Displaying iSLB CFS status using the show islb session status command:

switch# show islb status
iSLB Distribute is enabled
iSLB CFS Session exists

Displaying iSLB CFS Distribution Session Status

switch# show islb cfs-session status
last action : fabric distribute enable
last action result : success
last action failure cause : success

Displaying iSLB CFS Merge Status

switch# show islb merge status
Merge Status: Success

iSCSI High Availability with Host Running Multipath Software

The following figure shows the physical and logical topology for an iSCSI HA solution for hosts running multi-path software. In this scenario, the host has four iSCSI sessions. There are two iSCSI sessions from each host NIC to the two IPS ports.

Each IPS ports is exporting the same two Fibre Channel target ports of the storage but as different iSCSI target names if you use dynamic iSCSI targets). So the two IPS ports are exporting a total of four iSCSI target devices. These four iSCSI targets map the same two ports of the Fibre Channel target.

The iSCSI host uses NIC-1 to connect to IPS port 1 and NIC-2 to connect to IPS port 2. Each IPS port exports two iSCSI targets, so the iSCSI host creates four iSCSI sessions.

If the iSCSI host NIC-1 fails, then sessions 1 and 2 fail but we still have sessions 3 and 4.

If the IPS port 1 fails, the iSCSI host cannot connect to the IPS port, and sessions 1 and 2 fail. But sessions 3 and 4 are still available.

If the storage port 1 fails, then the IPS ports will terminate sessions 1 and 3 (put iSCSI virtual target iqn.com.cisco.mds-5.1-2.p1 and iqn-com.cisco.mds-5.1-1.p1 in offline state). But sessions 2 and 4 are still available.

In this topology, you have recovery from failure of any of the components. The host multi-path software takes care of load-balancing or failover across the different paths to access the storage.

iSCSI HA with Host Not Having Any Multipath Software

The above topology will not work if the host does not have multi-path software because the host has multiple sessions to the same storage. Without multi-path software the host does not have knowledge of the multiple paths to the same storage.

IP storage has two additional features that provide an HA solution in this scenario.

• IPS ports support the VRRP feature (see Configuring VRRP for IPStorage Interfaces section) to provide failover for IPS ports.

• IPS has transparent Fibre Channel target failover for iSCSI static virtual targets.

Statically imported iSCSI targets have an additional option to provide a secondary pWWN for the Fibre Channel target. This can be used when the physical Fibre Channel target is configured to have an LU visible across redundant ports. When the active port fails, the secondary port becomes active and the iSCSI session switches to use the new active port.

In the above figure, you can create an iSCSI virtual target that is mapped to both pWWN1 and pWWN2 to provide redundant access to the Fibre Channel targets.

The failover to a secondary port is done transparently by the IPS port without impacting the iSCSI session from the host. All outstanding I/Os are terminated with a check condition status when the primary port fails. New I/Os received during the failover are not completed and receive a busy status.

If you use LUN mapping, you can define a different secondary Fibre Channel LUN if the LU number is different.

Enable the optional revert-primary-port option to direct the IPS port to switch back to the primary port when the primary port is up again. If this option is disabled (default) and the primary port is up again after a switchover, the old sessions will remain with the secondary port and do not switch back to the primary port. However, any new session will use the primary port. This is the only situation when both the primary and secondary ports are used at the same time.

LUN Trespass for Storage Port Failover

In addition to the high availability of statically imported iSCSI targets, the trespass feature is available to enable the move of LUs, on an active port failure, from the active to the passive port of a statically imported iSCSI target.

In physical Fibre Channel targets, which are configured to have LUs visible over two Fibre Channel N ports, when the active port fails, the passive port takes over. Some physical Fibre Channel targets require that the trespass feature be used to move the LUs from the active port to the passive port. A statically imported iSCSI target's secondary pWWN option and an additional option of enabling the trespass feature is available for a physical Fibre Channel target with redundant ports. When the active port fails, the passive port becomes active, and if the trespass feature is enabled, the Cisco MDS switch sends a request to the target to move the LUs on the new active port. The iSCSI session switches to use the new active port and the moved LUs are accessed over the new active port.

Displaying configured iSNS profiles:

Use the show isns profile command to view configured iSNS profiles. Profile ABC has two portals registered with the iSNS server. Each portal corresponds to a particular interface. Profile XYZ has a specified iSNS server, but does not have any tagged interfaces configured.

switch# show isns profile
iSNS profile name ABC
tagged interface GigabitEthernet2/3
tagged interface GigabitEthernet2/2
iSNS Server 10.10.100.204
 
iSNS profile name XYZ
iSNS Server 10.10.100.211

switch# show isns profile ABC
iSNS profile name ABC
tagged interface GigabitEthernet2/3
tagged interface GigabitEthernet2/2
iSNS Server 10.10.100.204

Displaying all configured profiles with the iSNS PDU statistics for each tagged interface:

Use the show isns profile counters command to view all configured profiles with the iSNS PDU statistics for each tagged interface:

switch# show isns profile counters
iSNS profile name ABC
tagged interface port-channel 1
iSNS statistics
Input 54 pdus (registration/deregistration pdus only)
Reg pdus 37, Dereg pdus 17
Output 54 pdus (registration/deregistration pdus only)
Reg pdus 37, Dereg pdus 17
iSNS Server 10.10.100.204
 
iSNS profile name XYZ
tagged interface port-channel 2
iSNS statistics
Input 30 pdus (registration/deregistration pdus only)
Reg pdus 29, Dereg pdus 1
Output 30 pdus (registration/deregistration pdus only)
Reg pdus 29, Dereg pdus 1
iSNS Server 10.1.4.218

switch# show isns profile ABC counters
iSNS profile name ABC
tagged interface port-channel 1
iSNS statistics
Input 54 pdus (registration/deregistration pdus only)
Reg pdus 37, Dereg pdus 17
Output 54 pdus (registration/deregistration pdus only)
Reg pdus 37, Dereg pdus 17
iSNS Server 10.10.100.204

Displaying all objects registered on the iSNS server and specified in the given profile

Use the show isns command to view all objects registered on the iSNS server and specified in the given profile.

switch# show isns query ABC gigabitethernet 2/3
iSNS server: 10.10.100.204
Init: iqn.1991-05.com.w2k
Alias: <MS SW iSCSI Initiator>
Tgt : iqn.1987-05.com.cisco:05.172.22.94.22.02-03
Tgt : iqn.1987-05.com.cisco:05.172.22.94.22.02-03.210000203762fa34
nWWN: 200000203762fa34

Displaying the iSNS profile to which an interface is tagged

Use the show interface command to view the iSNS profile to which an interface is tagged

switch# show interface gigabitethernet 2/3
GigabitEthernet2/3 is up
Hardware is GigabitEthernet, address is 0005.3000.ae94
Internet address is 10.10.100.201/24
MTU 1500 bytes
Port mode is IPS
Speed is 1 Gbps
Beacon is turned off
Auto-Negotiation is turned on
iSNS profile ABC
^^^^^^^^^^^^^^^^
5 minutes input rate 112 bits/sec, 14 bytes/sec, 0 frames/sec
5 minutes output rate 0 bits/sec, 0 bytes/sec, 0 frames/sec
1935 packets input, 132567 bytes
4 multicast frames, 0 compressed
0 input errors, 0 frame, 0 overrun 0 fifo
1 packets output, 42 bytes, 0 underruns
0 output errors, 0 collisions, 0 fifo
0 carrier errors

Sample Scenario

The iSNS server provides uniform access control across Fibre Channel and iSCSI devices by utilizing both Fibre Channel zoning information and iSCSI access control information and configuration. An iSCSI initiator acting as an iSNS client only discovers devices it is allowed to access based on both sets of access control information. The following figure provides an example of this scenario.

The above figure displays iqn.host1 and iqn.host2 are iSCSI initiators. P1 and P2 are Fibre Channel targets. The two initiators are in different zones: Zone 1 consists of iqn.host1 and target P1, and Zone 2 consists of iqn.host2 and target P2. iSNS server functionality is enabled on both switches, SW-1 and SW-2. The registration process proceeds as follows:

1. Initiator iqn.host1 registers with SW-1, port Gigabitethernet2/1.

2. Initiator iqn.host2 registers with SW-2, port Gigabitethernet3/1.

3. Initiator iqn.host1 issues an iSNS query to SW-1 to determine all accessible targets.

4. The iSNS server in turn queries the Fibre Channel name server (FCNS) to obtain a list of devices that are accessible (that is, in the same zone) by the query originator. This query yields only P1.

5. The iSNS server then queries its own database to convert the Fibre Channel devices to the corresponding iSCSI targets. This is based on the iSCSI configuration, such as virtual-target and its access control setting or whether the dynamic Fibre Channel target import feature is enabled or disabled.

6. The iSNS server sends a response back to the query initiator. This response contains a list all iSCSI portals known to the iSNS server. This means iqn.host1 can choose to log in to target P1 through either SW-1 (at Gigabitethernet 2/1) or SW-2 (at Gigabitethernet 3/1).

7. If the initiator chooses to log in to SW-1 and later that port becomes inaccessible (for example, Gigabitethernet 2/1 goes down), the initiator has the choice to move to connect to target P1 through port Gigabitethernet 3/1 on SW-2 instead.

8. If the target either goes down or is removed from the zone, the iSNS server sends out an iSNS State Change Notification (SCN) message to the initiator so that the initiator can remove the session.

Target Discovery

iSCSI initiators discover targets by issuing queries to the iSNS server. The server supports DevGetNext requests to search the list of targets and DevAttrQuery to determine target and portal details, such as the IP address or port number to which to connect.

On receiving a query request from the iSCSI client, the iSNS server queries the Fibre Channel Name Server (FCNS) to obtain a list of Fibre Channel targets that are accessible by the querying initiator. The result of this query depends on zoning configuration currently active and current configuration(s) of the initiator. The iSNS server will subsequently use the iSCSI target configuration(s) (virtual target and dynamic import configuration) to translate the Fibre Channel target to an equivalent iSCSI target. At this stage it also applies any access control configured for the virtual target. A response message with the target details is then sent back to the query initiator.

The iSNS server sends a consolidated response containing all possible targets and portals to the querying initiator. For example, if a Fibre Channel target is exported as different iSCSI targets on different IPS interfaces, the iSNS server will respond with a list of all possible iSCSI targets and portals.

In order to keep the list of targets updated, the iSNS server sends state change notifications (SCN) to the client whenever an iSCSI target becomes reachable or unreachable. The client is then expected to rediscover its list of accessible targets by initiating another iSNS query. Reachability of iSCSI targets changes when any one of the following occurs:

• Target goes up or down.

• Dynamic import of FC target configuration changes.

• Zone set changes.

• Default zone access control changes.

• IPS interface state changes.

• Initiator configuration change makes the target accessible or inaccessible.

Viewing the ESI interval and the summary information about the iSNS database

Use the show isns config command to view the ESI interval and the summary information about the iSNS database contents.

switch# show isns config
Server Name: switch1(Cisco Systems) Up since: Fri Jul 30 04:08:16 2004
Index: 1 Version: 1 TCP Port: 3205
fabric distribute (remote sync): ON
ESI
Non Response Threshold: 5 Interval(seconds): 60
Database contents
Number of Entities: 2
Number of Portals: 3
Number of ISCSI devices: 4
Number of Portal Groups: 0

Displaying detailed information about the contents of the iSNS database:

Use the show isns database command to view detailed information about the contents of the iSNS database. This command displays the full iSNS database giving all the entities, nodes, and portals registered in the database. This command without options only displays explicitly registered objects. The asterisk next to the VSAN ID indicates that the iSCSI node is in the default zone for that VSAN.

switch# show isns database
Entity Id: dp-204
Index: 2 Last accessed: Fri Jul 30 04:08:46 2004
iSCSI Node Name: iqn.1991-05.comdp-2041
Entity Index: 2
Node Type: Initiator(2) Node Index: 0x1
SCN Bitmap: OBJ_UPDATED|OBJ ADDED|OBJ REMOVED|TARGET&SELF
Node Alias: <MS SW iSCSI Initiator>
VSANS: 1(*), 5(*)
Portal IP Address: 192.168.100.2 TCP Port: 4179
Entity Index: 2 Portal Index: 1
ESI Interval: 0 ESI Port: 4180 SCN Port: 4180

switch# show isns database full
Entity Id: isns.entity.mds9000
Index: 1 Last accessed: Fri Jul 30 04:08:16 2004
 
iSCSI Node Name: iqn.com.cisco.disk1
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000001
WWN(s):
22:00:00:20:37:39:dc:45
VSANS:
iSCSI Node Name: iqn.isns-first-virtual-target
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000002
 
VSANS:
iSCSI Node Name: iqn.com.cisco.disk2
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000003
WWN(s):
22:00:00:20:37:39:dc:45
 
VSANS:
Portal IP Address: 192.168.100.5 TCP Port: 3205
Entity Index: 1 Portal Index: 3
 
Portal IP Address: 192.168.100.6 TCP Port: 3205
Entity Index: 1 Portal Index: 5
 
Entity Id: dp-204
Index: 2 Last accessed: Fri Jul 30 04:08:46 2004
 
iSCSI Node Name: iqn.1991-05.com.microsoft:dp-2041
Entity Index: 2
Node Type: Initiator(2) Node Index: 0x1
SCN Bitmap: OBJ_UPDATED|OBJ ADDED|OBJ REMOVED|TARGET&SELF
Node Alias: <MS SW iSCSI Initiator>
 
VSANS: 1(*), 5(*)
Portal IP Address: 192.168.100.2 TCP Port: 4179
Entity Index: 2 Portal Index: 1
ESI Interval: 0 ESI Port: 4180 SCN Port: 4180

Note	The local option is only available for virtual targets.

switch# show isns database virtual-targets local
Entity Id: isns.entity.mds9000
Index: 1 Last accessed: Fri Jul 30 04:08:16 2004
 
iSCSI Node Name: iqn.com.cisco.disk1
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000001
WWN(s):
22:00:00:20:37:39:dc:45
 
VSANS:
iSCSI Node Name: iqn.isns-first-virtual-target
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000002
 
VSANS:
iSCSI Node Name: iqn.com.cisco.disk2
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000003
WWN(s):
22:00:00:20:37:39:dc:45
 
VSANS:
Portal IP Address: 192.168.100.5 TCP Port: 3205
Entity Index: 1 Portal Index: 3
 
Portal IP Address: 192.168.100.6 TCP Port: 3205
Entity Index: 1 Portal Index: 5

switch# show isns database virtual-targets switch 20:00:00:0d:ec:01:04:40
Entity Id: isns.entity.mds9000
Index: 1 Last accessed: Fri Jul 30 04:08:16 2004
 
iSCSI Node Name: iqn.com.cisco.disk1
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000001
WWN(s):
22:00:00:20:37:39:dc:45
 
VSANS:
iSCSI Node Name: iqn.isns-first-virtual-target
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000002
 
VSANS:
iSCSI Node Name: iqn.com.cisco.disk2
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000003
WWN(s):
22:00:00:20:37:39:dc:45
 
VSANS:
Portal IP Address: 192.168.100.5 TCP Port: 3205
Entity Index: 1 Portal Index: 3
 
Portal IP Address: 192.168.100.6 TCP Port: 3205
Entity Index: 1 Portal Index: 5

Displaying attributes of nodes registered with the iSNS server:

Use the show isns node command to display attributes of nodes registered with the iSNS server. If you do not specify any options, the server displays the name and node type attribute in a compact format; one per line.

switch# show isns node all
-------------------------------------------------------------------------------
iSCSI Node Name Type
-------------------------------------------------------------------------------
iqn.1987-05.com.cisco:05.switch1.02-03.22000020375a6c8 Target
...
iqn.com.cisco.disk1 Target
iqn.com.cisco.ipdisk Target
iqn.isns-first-virtual-target Target
iqn.1991-05.cw22 Target
iqn.1991-05.cw53 Target

switch# show isns node name iqn.com.cisco.disk1
iSCSI Node Name: iqn.com.cisco.disk1
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000001
WWN(s):
22:00:00:20:37:39:dc:45
VSANS: 1

switch# show isns node all detail
iSCSI Node Name: iqn.1987-05.com.cisco:05.switch1.02-03.22000020375a6c8f
Entity Index: 1
Node Type: Target(1) Node Index: 0x3000003
Configured Switch WWN: 20:00:00:0d:ec:01:04:40
WWN(s):
22:00:00:20:37:5a:6c:8f
VSANS: 1
...
iSCSI Node Name: iqn.com.cisco.disk1
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000001
Configured Switch WWN: 20:00:00:0d:ec:01:04:40
WWN(s):
22:00:00:20:37:39:dc:45
VSANS: 1
 
iSCSI Node Name: iqn.com.cisco.ipdisk
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000002
Configured Switch WWN: 20:00:00:0d:ec:01:04:40
WWN(s):
22:00:00:20:37:5a:70:1a
VSANS: 1
 
iSCSI Node Name: iqn.isns-first-virtual-target
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000003
Configured Switch WWN: 20:00:00:0d:ec:01:04:40
 
iSCSI Node Name: iqn.parna.121212
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000004
Configured Switch WWN: 20:00:00:0d:ec:01:04:40
 
iSCSI Node Name: iqn.parna.121213
Entity Index: 1
Node Type: Target(1) Node Index: 0x80000005
Configured Switch WWN: 20:00:00:0d:ec:01:04:40

Displaying the attributes of a portal along with its accessible nodes:

Use the show isns portal command to display the attributes of a portal along with its accessible nodes. You can specify portals by using the switch WWN-interface combination or the IP address-port number combination.

switch# show isns portal all
-------------------------------------------------------------------------------
IPAddress TCP Port Index SCN Port ESI port
-------------------------------------------------------------------------------
192.168.100.5 3205 3 - -
192.168.100.6 3205 5 - -

switch# show isns portal all detail
Portal IP Address: 192.168.100.5 TCP Port: 3205
Entity Index: 1 Portal Index: 3
 
Portal IP Address: 192.168.100.6 TCP Port: 3205
Entity Index: 1 Portal Index: 5

switch# show isns portal virtual
-------------------------------------------------------------------------------
IPAddress TCP Port Index SCN Port ESI port
-------------------------------------------------------------------------------
192.168.100.5 3205 3 - -
192.168.100.6 3205 5 - -

switch# show isns portal virtual switch 20:00:00:0d:ec:01:04:40
-------------------------------------------------------------------------------
IPAddress TCP Port Index SCN Port ESI port
-------------------------------------------------------------------------------
192.168.100.5 3205 3 - -
192.168.100.6 3205 5 - -

switch# show isns portal virtual switch 20:00:00:0d:ec:01:04:40 detail
Portal IP Address: 192.168.100.5 TCP Port: 3205
Entity Index: 1 Portal Index: 3
Switch WWN: 20:00:00:0d:ec:01:04:40
Interface: GigabitEthernet2/3
 
Portal IP Address: 192.168.100.6 TCP Port: 3205
Entity Index: 1 Portal Index: 5
Switch WWN: 20:00:00:0d:ec:01:04:40
Interface: GigabitEthernet2/5

Displaying the attributes of an entity along with the list of portals and nodes in that entity:

Use the show isns entity command to display the attributes of an entity along with the list of portals and nodes in that entity. If you do not specify any option, this command displays the entity ID and number of nodes or portals associated with the entity in a compact format; one per line

switch1# show isns entity
-------------------------------------------------------------------------------
Entity ID Last Accessed
-------------------------------------------------------------------------------
dp-204 Tue Sep 7 23:15:42 2004

switch# show isns entity all
 
-------------------------------------------------------------------------------
Entity ID Last Accessed
-------------------------------------------------------------------------------
isns.entity.mds9000 Tue Sep 7 21:33:23 2004
 
dp-204 Tue Sep 7 23:15:42 2004

switch1# show isns entity id dp-204
Entity Id: dp-204
Index: 2 Last accessed: Tue Sep 7 23:15:42 2004

switch1# show isns entity all detail
Entity Id: isns.entity.mds9000
Index: 1 Last accessed: Tue Sep 7 21:33:23 2004
 
Entity Id: dp-204
Index: 2 Last accessed: Tue Sep 7 23:16:34 2004

switch# show isns entity virtual
Entity Id: isns.entity.mds9000
Index: 1 Last accessed: Thu Aug 5 00:58:50 2004
 
Entity Id: dp-204
Index: 2 Last accessed: Thu Aug 5 01:00:23 2004

Displaying information about import targets

Use the show iscsi global config command to display information about import targets

switch# show isns iscsi global config switch 20:00:00:05:ec:01:04:00
iSCSI Global configuration:
Switch: 20:00:00:05:ec:01:04:00 iSCSI Auto Import: Enabled

switch# show isns iscsi global config all
iSCSI Global configuration:
Switch: 20:00:44:0d:ec:01:02:40 iSCSI Auto Import: Enabled

Displaying CFS peers switch information about the iSNS application

Use the show cfs peers command to display CFS peers switch information about the iSNS application:

switch# show cfs peers name isns
 
Scope : Physical
--------------------------------------------------
Switch WWN IP Address
--------------------------------------------------
20:00:00:00:ec:01:00:40 10.10.100.11 [Local]
 
Total number of entries = 1