HP9000 : Is it possible to set up an HP9000 running HP-UX 11.0 as a multi-homed host?

I have an HP9000 K420 box running HP-UX 11.0.  The standard NIC that comes with this box is a 10-baseT variety.  I recently added a card to the server, which has two 100-baseT ports, with the idea of spreading my network traffic over multiple NICs.  I need all three NICs to be on the same sub-net and I don't know if that's possible.

After installing the hardware, I added the two new NICs to the system via 'sam'.  The only prompt that I got during this process was that an alias was required, which I entered.  Both 100-baseT NIC showed as 'enabled' on the 'sam' screen, along with the 10-baseT NIC.  At this point, all of my network traffice to the 10-baseT NIC was functional.  The following three lines are now in /etc/hosts :  araphp  lan10bt1    (this was the original line prior to the addition of the new NICs)  araphp  lan100bt1  araphp  lan100bt2

At this point, I stopped for the day.  My system reboots each night in preparation for a backup.  The following day, after the reboot,
I had no connectivity to my 10-baseT NIC.  No cables had been moved.  No settings changed, at least on my part.  I went into 'sam' and disabled the two 100-baseT NICs and my connectivity began working on my 10-baseT NIC, again.  I then re-enabled the two 100-baseT NICs.  However, I did not connect them to the network.  They were simply enabled.  Following morning, same problem.

Is there a setting that I am missing?  Do I need to run any additional services to make this work?  Can all three NICs reside on the same sub-net?

I would appreciate any help that you can provide.

Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

>Is there a setting that I am missing?
>  Do I need to run any additional services to make this work?
>  Can all three NICs reside on the same sub-net?
Yes, you need to set netmask to 0xFFFFFFFF for additional NIC's in same subnet
check /etc/rc.config.d/netconf  file to verify all the network settings for each NIC
to make sure they are correct

No proble to have all of then in the same subnet:


... etc, you can use vi to edit the file, and then reboot.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
ggs54Author Commented:
Okay.  I removed the new 100BT NICs from the system, including any lines referring to these NICs in both /etc/hosts and /etc/rc.config.d/netconf.  Next, I re-added ONE of the 100BT NICs via 'sam'.  Here is a partial listing relevant to the NICs that appears in each of those two files:

#server and local loopback araphp lan10bt1 #lan10bt1_10base-t_port1 araphp lan100bt1 #lan 100 base t port 1       localhost       loopback


# Internet configuration parameters.  See ifconfig(1m), autopush(1m)



At this point, all network connectivity to the system stops working.  When the 100BT NIC is disabled, connectivity returns to normal.

With the holiday weekend, I won't be able to experiment with the system because we are a retail operation.  I appreciate your help and hope that you have a good Thanksgiving.

Big Business Goals? Which KPIs Will Help You

The most successful MSPs rely on metrics – known as key performance indicators (KPIs) – for making informed decisions that help their businesses thrive, rather than just survive. This eBook provides an overview of the most important KPIs used by top MSPs.

what happens when you disable old NIC ???

most likely kernel has hard time figuring out which interface to use, add netmask of to one you like less
ggs54Author Commented:
Thanks for your suggestion.  I'm at a point where I can't disable the old NIC because of the time of year.  I just can't bring the system down and something is running on it almost 24 hours a day.  However, I'm fortunate to have an identical system, which we purchased in lieu of buying the expensive HP hardware support.  On Monday, I'm going to set it up and begin to do some experimentation, using the suggestions from all those who have responded to this question.  One of the things that I want to try is exactly what you have suggested, which is to effectively replace the 10BT with one of the 100BT NICs and see what happens.

Happy Thanksgiving and thanks for taking the time to try and lend a hand.
Check `netstat -r`after adding the interface; I suspect that HP-UX is adding a route to the "new" network via the new interface as it's configured in - Which may remove the existing routing info, and may also foul up the default route (presumably via lan0)
ggs54Author Commented:
Okay. Here's what I've done.
Set up my second server with identical hardware and OS.  This unit allows me to set up all three NICs without any problems.  The only difference is that the 100BT NIC board on my primary unit was installed after the OS.  On my backup unit, it was installed before.  So, I went back to my primary unit and did the following, all using 'sam'.

1. Removed the 10BT NIC from the configuration  Original IP was
2. Changed the 100BT #1 NIC to
3. Enable the 100BT #1 NIC
4. 100BT #2 NIC was left disabled

Here's the 'sam' and netstat -r listings, after completing the above steps.
Network Interface Cards                                    0 of 3 selected:

 Card             Interface   Hardware                    Internet    
 Type             Name        Path       Status           Address    

 Ethernet           lan0        10/12/6    Not Configured    
 Fast Ethernet    lan1        10/8/1/0   Enabled  
 Fast Ethernet    lan2        10/8/2/0   Disabled

#netstat -r

Routing tables
Dest/Netmask       Gateway         Flags  Refs       Use  Interface  Pmtu
localhost              localhost         UH       0         2274  lo0        4136
araphp                araphp            UH       0              0  lan2       4136
araphp                araphp            UH       0              0  lan1       4136              araphp            U         2              0  lan1       1500            localhost          U         0              0  lo0        4136
default             UG       0              0  lan1       1500

Network traffic works properly through the address.

Next, I enable the 100BT #2 NIC  (
Here's the sam and netstat listings:

Network Interface Cards                                    0 of 3 selected:

 Card               Interface   Hardware                    Internet    
 Type               Name        Path       Status           Address    

 Ethernet          lan0        10/12/6    Not Configured    
 Fast Ethernet   lan1        10/8/1/0   Enabled  
 Fast Ethernet   lan2        10/8/2/0   Enabled

#netstart -r

Routing tables
Dest/Netmask       Gateway      Flags  Refs       Use  Interface  Pmtu
localhost          localhost          UH      0          2418  lo0        4136
araphp             araphp            UH      0               0  lan2       4136
araphp             araphp            UH      0               0  lan1       4136           araphp            U        2               0  lan2       1500           araphp            U        2               0  lan1       1500          localhost         U        0               0  lo0        4136
default          UG      0               0  lan1       1500

At this point, I have network connectivity on both 100BT NICs.  However, if I try and enable the 10BT NIC, everything stops working.  Since this change allows me to go from one 10BT NIC to two 100BT NICs, I have the network capacity that I need and I'm not going to worry about it.  I just don't know why one system works and the other does not.  If you have any thoughts, I'd like to hear them.  

I'm going to leave this question open for one more day and then assign points.

Thanks for your input.
That's a good news you get it going.

I just can't understand any valid reason different speed of NIC can cause problem, it
might have something to do with the configuration in your switch (port settings).
ggs54Author Commented:

I don't think the problem is with the switch.  I have other devices that are 10BT and they work properly. My switch is auto-sensing and has never caused any problems.   Also, my backup unit, which had been working with all three NICs enabled, stopped working after a reboot.  I removed the 10BT NIC from that configuration and both of the remaining 100BT NIC began working immediately.  There must be some configuration conflict within my HP-UX box, but I don't have a clue what that would be and at this point, I have the perfomance from the systems that I need.

Thanks, again, for taking the time to help.
some switch+NIC combinations cause problems ( i will not mention few examples to avoid brandname bashing wars....)
if speed drops arounds 1/100 of what is expected, consider exp-loring switch port and nic LED lights and other signs of media settings, this should be done all along network path then.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.