Connecting to a peer in a different LPAR

Red Hat Enterprise Linux 9.2 LPAR mode

A Linux® instance and a peer run in LPAR mode on the same or on different mainframes and are to be connected with a CTC FICON® or CTC ESCON network interface.

Assumptions:
  • Locally, the read and write channels have been configured for type 3088 and use device bus-IDs 0.0.f008 and 0.0.f009.
  • IP address 10.0.50.4 is to be used locally and 10.0.50.5 for the peer.

Figure 1 illustrates a CTC setup with a peer in a different LPAR.

Figure 1. CTC scenario with peer in a different LPAR
This graphic is explained in the preceding text.

Procedure

  1. Create a CTCM group device.
    Issue: 
    # echo 0.0.f008,0.0.f009 > /sys/bus/ccwgroup/drivers/ctcm/group
  2. Confirm that the device uses CTC FICON or CTC ESCON: 
    # cat /sys/bus/ccwgroup/drivers/ctcm/0.0.f008/type
ESCON
    In this example, ESCON is used. You would proceed the same for FICON.
  3. Select a protocol.
    The choice depends on the peer.
    If the peer is ... Choose ...
    Linux 1
    z/OS® or OS/390 3
    Any other operating system 0
    Assuming that the peer is Linux: 
    # echo 1 > /sys/bus/ccwgroup/drivers/ctcm/0.0.f008/protocol
  4. Set the CTCM group device online and find out the assigned interface name: 
    # echo 1 > /sys/bus/ccwgroup/drivers/ctcm/0.0.f008/online
# ls /sys/devices/ctcm/0.0.f008/net/
slcf008
    In the example, the interface name is slcf008.
  5. Assure that the peer interface is configured.
  6. Activate the interface locally and on the peer.
    If you are connecting two Linux instances, either instance can be activated first. If the peer is not Linux, activate the interface on Linux first. To activate the local interface: 
    # ip addr add 10.0.50.4 dev slcf008 peer 10.0.50.5 
# ip link set dev slcf008 up