topic Re: Force FTP on lan1 on specific interface in Operating System - HP-UX

Force FTP on lan1 on specific interface

Mangalam — Thu, 24 Oct 2013 09:03:22 GMT

Hi All,

I have this particular problem which I understand is possible in Linux using iptables.

I would like to know how to achieve this in HP-UX.

I have a HP-UX server with 2 NIC cards - lan0 and lan1 (both on same subnet)

This server keeps doing regular routine tasks and need to transfer files to different remote machines on frequent basis.

What I need is that all the file transfers (especially FTP or SFTP) should happen using lan1 rather than lan0 (which is default)

Your guidance will be really appreciated.

Thanks

Mangalam

Re: Force FTP on lan1 on specific interface

Torsten. — Thu, 24 Oct 2013 10:25:22 GMT

> I have a HP-UX server with 2 NIC cards - lan0 and lan1 (both on same subnet)

Is this APA?
Multiple NICs in same subnet may cause a lot of trouble... you should avoid this.

Re: Force FTP on lan1 on specific interface

Mangalam — Thu, 24 Oct 2013 10:33:00 GMT

Hi Torsten,

Even I heard that multiple NIC on same subnet might cause problems. Why is that ? Any specific reason ?

Next, at the moment we dont have APA. In this case Is it possible to achieve the requirements I mentioned ? How ?

Is it possible using APA ? How ?

Thanks

Mangalam

Re: Force FTP on lan1 on specific interface

Torsten. — Thu, 24 Oct 2013 11:08:55 GMT

Using APA you can "bond" the physical NICs together and create a single logical interface, maybe the better solution in this case.

Re: Force FTP on lan1 on specific interface

Mangalam — Thu, 24 Oct 2013 11:22:42 GMT

Hi Torsten,

Why do multiple NIC with same subnet create problem ?

Using APA, I will surely be able to bond multiple NICs together and all traffic will be common to this logical interface but my requirement is a dedicated NIC only for FTP connections.
Is this possible with/without additional S/W?

Thanks
Mangalam

Re: Force FTP on lan1 on specific interface

Torsten. — Thu, 24 Oct 2013 11:50:26 GMT

You will have problems if not using ip_strong_es_model.

Best description I can find for the moment
(maybe the best anyway):

http://www.mayoxide.com/presentations/Understanding_hpux_routing.pdf

Problem in very, very short:
application is sending data over NIC1 and waits for answer, but answer received to NIC0, so NIC1 will receive nothing.

See the related thread:

http://h30499.www3.hp.com/t5/Networking/Resolving-asymmetric-routing-with-ip-strong-es-model/td-p/5127552#.UmkJOxC3CUU

Re: Force FTP on lan1 on specific interface

Mangalam — Thu, 24 Oct 2013 12:07:01 GMT

Thanks Torsten...
One last query - If I assign different subnet (say X) to one of the NIC and place the other machine where the files should be copied on same subnet X, in that case both subnets can be configured on NIC cards of HP-UX and FTP will happen dedicatedly on seperate interface.
Correct ?

Thanks
Mangalam

Re: Force FTP on lan1 on specific interface

Torsten. — Thu, 24 Oct 2013 12:10:20 GMT

Yes, the system will route the traffic to the different subnet to the specific NIC.

Re: Force FTP on lan1 on specific interface

Mangalam — Thu, 24 Oct 2013 12:17:02 GMT

Thanks Torsten for your super quick responses.
Appreciate all your time and support

Regards
Mangalam