topic Re: UCX- Interface --LO0-Counters in Operating System - OpenVMS

UCX- Interface --LO0-Counters

arun sanghvi — Thu, 19 Apr 2007 14:33:20 GMT

We noticed send and receive counters going up for Interface LO0 under UCX.

What is the significance of the interface and why the counter keeps going up when there are nobody is running loopback test

Thanks

Arun Sanghvi

Re: UCX- Interface --LO0-Counters

Steven Schweda — Thu, 19 Apr 2007 21:32:29 GMT

It's not unusual for various programs to use
the "loopback" interface. It's even more
common on VMS than on UNIX, because UNIX
supports UNIX sockets (address family =
AF_UNIX) as well as IP sockets (address
family = AF_INET), and so some VMS programs
use an IP socket on 127.0.0.1, where a
similar program on UNIX might use a (non-IP)
UNIX socket.

I believe that the ssh and ssh_agent programs
do this to talk to each other, for example.

It's nothing to worry about.

Re: UCX- Interface --LO0-Counters

Jim_McKinney — Fri, 20 Apr 2007 07:11:29 GMT

Many folks run a DNS on their VMS hosts (sometimes in caching-only mode with forwarders) and use it to resolve all their DNS queries. In this case they would designate 127.0.0.1 as the address of their DNS. Perhaps this matches your configuration?

Re: UCX- Interface --LO0-Counters

Wim Van den Wyngaert — Mon, 23 Apr 2007 02:03:27 GMT

I once tested the usage of the LO interface with Sybase servers (instead of the nodename IP address). It was slightly faster (<10%)with the LO interface but I didn't keep data of the test results.

Wim