TCP/IP Configuration and Management Manual
Configuring the NonStop TCP/IP Subsystem
TCP/IP Configuration and Management Manual—427132-004
3-11
Configuration 2: Startup Files for a Host in a Subnet
Addressing Environment
The configuration in SCFBNT allows HOST1 to communicate with the three subnets
shown in Figure 3-2:
128.30.192.0 (the local subnet for HOST1 and HOST2)
128.30.64.0 (a remote subnet for HOST3 and HOST4)
128.30.32.0 (a remote subnet for HOST5 and HOST6)
When you add SUBNET objects to the NonStop TCP/IP process, the process needs to
know what mask is being applied to messages on that SUBNET. Use the ALTER
SUBNET commands to change the subnet mask from the default to %HFFFFFF00.
The routes also reflect the new configuration. The ADD ROUTE command for $ZTC0
provides access to the backbone and subnets 128.30.32.0 and 128.30.64.0. The
routing for the second NonStop TCP/IP process ($ZTC1) continues to use a default
address.
The HOSTS File
The HOSTS file, shown in Example 3-5, contains address changes for our second
sample configuration. You can use this HOSTS file for all the hosts in the sample
configuration. Communication destined for HOST1 defaults to the line $LAN01, but you
can call HOST1B to address the other line.
Further Subnetting Options
Once again, assume that you have a Class B IP network address. By reasonably
projecting growth, you determine that you can split the subnet and host IDs on the
octet boundary to provide for 254 subnets with 254 possible hosts on each subnet. The
subnet mask would be:
11111111 11111111 11111111 00000000
that is, %HFFFFFF00.
Over the next year, however, your organization decides to expand its operations and
the number of its networks. You no longer need as many hosts attached to each
subnet as you originally planned on; however, you do need to fit more than 254
subnets into your addressing scheme.
Example 3-5. Second HOSTS File for TCPIPUP2
########## HOSTS FOR HOST1 ########## HOSTS FOR HOST1 ############
# Filename = \CB1.$SYSTEM.ZTCPIP.HOSTS
127.0.0.1 me loop
128.30.192.2 host1 h1
128.30.192.3 host1b h1b
128.30.192.4 host2 corp2
128.30.64.6 host3 corp3
128.30.64.7 host4 corp4
128.30.32.9 host5 RD1
128.30.32.10 host6 RD2
###########END OF HOSTS ##################END OF HOSTS ###########