HP-UX 11i June 2001 Release Notes

Internet and Networking Services
Network Transport (new at 11i original release)
Chapter 10 205
Beginning at HP-UX 11i, netstat -I < interface > displays statistics
accumulated since the last system reboot. This matches netstat -I
output for HP-UX releases 10.20 and earlier.
Compatibility Issues
There could be some compatibility problems with scripts where they look
for the “Use” field.
Virtual IP (VIP) Address for the System
Using the loopback interface lo0:1, lo0:2 and so on, the system will
respond to the IP address assigned to these interfaces using any physical
interface. Thus, a system can now have a “systemIP” address that will be
available as long as one interface stays usable.
In some configurations, a system needs to keep a “well known” IP
address that will always be available even if an interface goes down.
With the new VIP feature, a remote user can specify an IP address that
will respond regardless of the local interface where the packet arrived.
This feature is an enhancement.
setsockopt()
The system-wide kernel parameters, tcp_recv_hiwater_max (for TCP
sockets) and udp_recv_hiwater_max (for UDP sockets), now limit the
maximum buffer sizes specified in the SO_SNDBUF or SO_RCVBUF
setsockopt() parameters.
A setsockopt() call with a SO_SNDBUF or SO_RCVBUF option that
exceeds the corresponding kernel parameter value will fail, returning
the errno value EINVAL.
If you determine that certain applications always ask for the largest
socket buffer allowed, then you may want to set these variables and limit
the amount of memory used by such applications. When an application
opens enough of these large sockets and the system does not contain a lot
of memory, then the system may starve for memory if the application
quits reading from the socket.
Applications that request sockets with send or receive buffers larger
than high-water marks set by the administrator will fail. The errno
value returned is EINVAL.