How to clear DNS cache in PI

[mark_meilleur]

A trading partner of ours changed IP addresses over the weekend. We have been and continue to post to a DNS for them, which we thought would prevent us from having any troubles communicating. It seems that PI has cached the prior IP address so we are timing out trying to connect to them using their DNS. How/where do I go about clearing this cache in PI? I've tried a couple of the options from the Cache overview section of the Administration page to no avail. We've also run the command ipconfig /flushdns on both of our PI servers with no luck.

Any suggestions???

Thank you in advance for your help.

[former_member302337]

Try going to NWA>operations>systems>start & stop>"clear dns cache" for each instance available.

[marksmyth]

Hello Mark

Check the blog below, which I think will provide the info you require.

Controlling DNS caching in the Java Virtual Machine (i.e. J2EE WAS)

/people/dagfinn.parnas/blog/2005/06/20/controlling-dns-caching-in-the-java-virtual-machine-ie-j2ee-was

P.S. Please close the thread if your query has been answered.

Regards

Mark

[Former Member]

Mark,

Can you please do a complete Cache Refresh as give in the below document.

http://www.sdn.sap.com/irj/scn/go/portal/prtroot/docs/library/uuid/c0332b2a-eb97-2910-b6ba-dbe52a01b...

Thanks

Aamir

[Former Member]

Hey Mark,

Sometimes it does happens that DNS name does not maps to IP address due to which you may get error.

I remember having this issue while configuring HTTP or SOAP receiver communication channels.

Please do a revere DNS lookup to see if DNS is correctly mapped to the IP address (you can use any site on google for this).

If you see that mapping of DNS to IP is done correctly then PI channel should work correctly, but if the mapping is not done correctly, then try replacing the DNS with the actual IP address of the partner in the receiver HTTP communication channel.

Hope that helps.

Thanks

Aamir

[mark_meilleur]

Hi Aamir,

I hope all is well with you. I tried emailing you directly with this, but my message was returned. At least you got it thru here.

I did the reverse lookup, and the ip address returned what looks like their ISP DNS, not what we have entered in their communication channel. However, I did hit their system using their DNS from IE on my desktop. Also, we have pinged their DNS and it has returned the correct IP address, from both our desktops and the PI server itself.

We did try to replace the DNS with the IP address, and it did not work either. They came back and said that this was not possible due to their system configuration.

[marksmyth]

Hello Mark

The Caching of IP addresses is independent of SAP XI. There is no mechanisim to refresh the IP cache for any specific

channel/host names. This issue is related to the underlying JVM implentation.

Have you tried restarting the java engine? This usually clears all caches.

Regards

Mark

[Former Member]

Restarting of the java engine while PI is running?

Yes, sorry for the stupid question - with this being PRD-PI and only 1 trading partner, seems excessive to have to restart PI SAP and/or java engine

Regards