Fibre Channel port masking
With Fibre Channel port masking, you control the use of Fibre Channel ports. You can control whether the ports are used to communicate to other nodes within the same local system, and if they are used to communicate to nodes in partnered systems. Fibre Channel port masking does not affect host or storage traffic. It gets applied only to node-to-node communications within a system and replication between systems.
Usefulness of Fibre Channel port masking
What is Fibre Channel port masking
Port numbers refer to the Fibre Channel I/O port IDs that are shown by the lsportfc command.
A port mask is a string of zeros and ones. The last digit in the string represents port one.
The previous digits represent ports two, three, and so on. If the digit for a port is 1
,
the port is enabled and the system attempts to send and receive traffic on that port. If it is
0
, the system does not send or receive traffic on the port. If there are not sufficient
digits in the string to specifically set a port number, the port is disabled for traffic.
For example, if the local port mask is set to 00001100
on a node with eight Fibre
Channel ports, ports 3 and 4 are able to connect with other nodes in the system. The other Fibre
Channel ports are not able to be used for node-to-node communication.
The port masks are set by using the chsystem CLI command.
SAN Volume Controller 2145-SV1 port masking example
The following table shows recommended port masking for 2145-SV1 systems with 4, 8, 12, and 16 Fibre Channel ports. The number of 0s and 1s in the port mask examples match the number of ports.
Adapter / Port | 4 ports | 8 ports | 12 ports | 16 ports | SAN Fabric |
---|---|---|---|---|---|
Adapter 1 Port 1 | Host and Storage | Host and Storage | Host and Storage | Host and Storage | A |
Adapter 1 Port 2 | Host and Storage | Host and Storage | Host and Storage | Host and Storage | B |
Adapter 1 Port 3 | Intracluster and Replication | Intracluster | Intracluster | Intracluster | A |
Adapter 1 Port 4 | Intracluster and Replication | Intracluster | Intracluster | Intracluster | B |
Adapter 2 Port 1 | - | Host and Storage | Host and Storage | Host and Storage | A |
Adapter 2 Port 2 | - | Host and Storage | Host and Storage | Host and Storage | B |
Adapter 2 Port 3 | - | Intracluster or Replication | Replication or Host and Storage | Replication or Host and Storage | A |
Adapter 2 Port 4 | - | Intracluster or Replication | Replication or Host and Storage | Replication or Host and Storage | B |
Adapter 3 Port 1 | - | - | Host and Storage | Host and Storage | A |
Adapter 3 Port 2 | - | - | Host and Storage | Host and Storage | B |
Adapter 3 Port 3 | - | - | Intracluster | Intracluster | A |
Adapter 3 Port 4 | - | - | Intracluster | Intracluster | B |
Adapter 4 Port 1 | - | - | - | Host and Storage | A |
Adapter 4 Port 2 | - | - | - | Host and Storage | B |
Adapter 4 Port 3 | - | - | - | Replication or Host and Storage | A |
Adapter 4 Port 4 | - | - | - | Replication or Host and Storage | B |
localfcportmask | 1100 | 11001100 or 00001100 | 110000001100 | 0000110000001100 | - |
remotefcportmask | 1100 | 00000000 or 11000000 | 000011000000 | 1100000011000000 | - |
- Host refers to host objects defined in the system.
- Replication refers to nodes that are part of a different cluster.
- Storage refers to controller objects defined in the system if external storage is being used.
- Intracluster refers to nodes within the same cluster.
- The word "and" indicates that both types are used.
- The word "or" indicates that one of the options must be selected. If using replication, preference should be given to replication.