HP-UX 11.0, interface aliases and broadcast...

[Laurent Therond]

Hi,

Could anyone confirm whether the following behavior is normal:

- 1 physical interface: lan0
- 1 alias: lan0:1

When broadcasting on lan0:1, packets appear on the network twice:

a) With the IP address associated with lan0 as a source address

b) With the IP address associated with lan0:1 as a source address

I turned IP forwarding off.

Should this behavior be expected?

What is the most likely configuration mistake I may have made?

Thank you for your attention.

Regards,

Laurent

[Laurent Therond]

After further investigation, this appears to be a defect that breaks HP-UX 11.0 POSIX compliance.

[Christopher Caldwell]

Not sure cazactly what you're asking, but I believe the concept of interface alias is mostly a "listening" concept. It's all in the way the software is written; while many software servers recieve on aliased ports, most software speaks from the base IP of the system.

Servers like httpd can bind to single IP - traffic is to and from that IP. Ping, telnet, ftp from that same box will look like it comes from the base host.

[Laurent Therond]

Christopher,

Thank you for your comment.

That's exactly my point.

When the IP address of lan0:1 is specified to signify that broadcast should be done via lan0:1, broascast should occur only once and packets resulting from that broadcast should have the base address as their source address.

To that respect, HP-UX 11.0 appears to be broken.

Regards,

L.