IP logical interface - status and pkt info

[wendy sechler]

Once you create a logical IP interface with the "ifconfig"
command, does HPUX keep track of its status (UP,DOWN, RUNNING, etc) and
input/output packets SEPARATE from that of the physical network interface?

For example,
# ifconfig lan0:1 19.43.9.222
# lanscan
Hardware Station Crd Hdw Net-Interface NM MAC HP-DLPI DLPI
Path Address In# State NamePPA ID Type Support Mjr#
0/0/0/0 0x00306E08CF63 0 UP lan0 snap0 1 ETHER Yes 119

Is there anyway that the logical ip (19.43.9.222) can be reported as UP while
the physical interface can be reported as DOWN?

# netstat -in
Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll
lan0:1 1500 9.0.0.0 19.43.9.222 516 0 3070 0 0
lan0 1500 9.42.7.0 9.42.7.182 84022 0 16266 0 53
lo0 4136 127.0.0.0 127.0.0.1 1294 0 1294 0 0

On netstat -i, do Ierrs, Oerrs, Coll numbers ever apply to lan0:1 or will they
always be 0 for logical IP interfaces?

[Sanjay_6]

Hi,

any stats for lan0:1 applies to the logical interface.

Hope this helps.

Regds

[wendy sechler]

I know the stats I see for lan0:1 apply to the logical interface but my questions are:

I don't see a separate status (UP, DOWN) for lan0:1. Does one exist separate from lan0 anywhere?

Should I ever expect stats for Ierrs, Oerrs and Coll on the logical interface? I think that the answer is "no" because those stats seems like they should only apply to physical interfaces but netstat -i output is unclear on this since it reports "0"s for those statistics on a logical interface.

[Steven E. Protter]

The real network traffic in this scenario is travelling through the same physical interface. There is no value for load balancing or other considerations in geting this data.

You might be able to maniuplate netstat or use nettl or ethreal packet monitoring to get this information.

The logical interface does not change the overall load the card can handle.

I agree it should be possible to get this information but the situation is kind of murky.

On my linux machines where I do a lot of this type of virutal networking, I've sucessfully brought down eth0 while eth0:1 stays up.

The physical Inter fade is up the whole time. Only when ALL the virutal IP addresses are brought down does the card stop responding to ping requests.

Fromyour data, HP-UX seems to work the same way.

In my far from expert opinion, the netstat data is really for the entire interface, since collisions are if I remember correctly a physical event.

SEP