Examples for setting up a network concentrator
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An example of a network environment with a network concentrator.
Figure 1 shows a network environment where a Linux® instance C acts as a network concentrator that connects other operating system instances on a HiperSockets™ LAN to an external LAN.

- Setup for the network concentrator C:
- The HiperSockets interface hsi0 (device bus-ID
0.0.a1c0) has IP address 10.20.30.51/24. The default gateway is 10.20.30.1.
Issue:
# echo primary_connector > /sys/bus/ccwgroup/drivers/qeth/0.0.a1c0/route4
The OSA-Express CHPID in QDIO mode interface eth0 (with device bus-ID 0.0.a1c4) has IP address 10.20.30.11/24. The default gateway is 10.20.30.1.
Issue:# echo multicast_router > /sys/bus/ccwgroup/drivers/qeth/0.0.a1c4/route4
To enable IP forwarding issue:# sysctl -w net.ipv4.ip_forward=1
Tip: See SUSE Linux Enterprise Server 15 SP5 Administration Guide for information about using configuration files to automatically enable IP forwarding when Linux boots.To remove the network routes for the HiperSockets interface issue:# ip route del 10.20.30/24
To start the HiperSockets network concentrator issue:# service hsnc start
- Setup for G:
- No special setup required. The HiperSockets interface has IP address 10.20.30.54/24. The default gateway is 10.20.30.1.
- Setup for workstation:
- No special setup required. The network interface IP address is 10.20.30.120/24. The default gateway is 10.20.30.1.
Figure 2 shows the example of Figure 1 with an additional mainframe. On the second mainframe a Linux instance D acts as a HiperSockets network concentrator.

The configuration of C, G, and the workstation remain the same as for Figure 1.
- Setup for the network concentrator D:
- The HiperSockets interface hsi0 has IP address
0.0.0.0. Assuming that the device bus-ID of the HiperSockets interface is 0.0.a1d0, issue:
# echo primary_connector > /sys/bus/ccwgroup/drivers/qeth/0.0.a1d0/route4
The OSA-Express CHPID in QDIO mode interface eth0 has IP address 10.20.30.50/24. The default gateway is 10.20.30.1.
D is not configured as a multicast router, it therefore only forwards unicast packets.
To enable IP forwarding issue:# sysctl -w net.ipv4.ip_forward=1
Tip: See SUSE Linux Enterprise Server 15 SP5 Administration Guide for information about using configuration files to automatically enable IP forwarding when Linux boots.To start the HiperSockets network concentrator issue:# service hsnc start
- Setup for H:
- No special setup required. The HiperSockets interface has IP address 10.20.30.55/24. The default gateway is 10.20.30.1.