TCP/IPv6 Configuration and Management Manual (G06.29+, H06.03+, J06.03+)

Manage the NonStop TCP/IPv6 Subsystem
HP NonStop TCP/IPv6 Configuration and Management Manual—524523-012
6-6
Application Isolation
Some constraints affecting NonStop TCP/IPv6 (as well as other QIO clients) include
the reduction of QIO memory space to 128 MB when QIO is moved to Kseg2 on the
NonStop S-series server. (On the Integrity NonStop server, the QIO memory space in
global privileged space is 256 MB.) The available QIO memory space impacts the
number of LIFs that you can configure on your system because LIFs use QIO memory.
It also impacts the number of sockets that can be opened because open sockets use
QIO memory as well. For the NonStop S-series servers, 128 MB might not be sufficient
for your NonStop TCP/IPv6 or other QIO client needs.
For details about planning for and using the new QIO features, see the QIO
Configuration and Management Manual.
Application Isolation
In the NonStop TCP/IPv6 environment, all applications have access to all interfaces (IP
addresses). If you want to isolate which interface an application listens on, see Logical-
Network Partitioning (LNP) on page 2-7.
Using the Domain Name Server (DNS) and
IPNODES and HOSTS Files
You only have to add a DEFINE for the IPNODES file when you want to place the
IPNODES file in a location other than the default ($SYSTEM.ZTCPIP.IPNODES). The
Guardian socket library behaves in this manner:
1. The socket library looks for the HOSTS DEFINE. If it finds this DEFINE, then it
looks for the IPNODES file.
a. If it finds IPNODES, it notes the location.
b. If it does not find IPNODES, it notes the location of the HOSTS file.
2. When the socket library needs to look up all addresses for a given host name, it
performs these:
a. For an IPv4 host, the socket library goes to IPNODES and looks for the
address. If it does not find the IPv4 address, it goes and looks for it in the
HOSTS file.
Note. The default configuration for the QIO subsystem has not changed.
Note. Whether you use the default QIO configuration or one of the newly supported custom
configurations, you do not need to change anything in
NonStop TCP/IPv6; all changes are
made in the QIO subsystem.
Note. The socket library performs these functions for the gethostbyname and
getaddrinfo library calls. For information about these calls, see TCP/IP Programming
Manual.