RE: RAC 10.2.0.3

Regardless of whether or not Path MTU discovery is enabled, the MTU will never go larger than the configured MTU of the Ethernet interface - which by default is 1500 bytes. If you want to use jumbo frames (>1500 byte mtus), you need to configure the interface using ifconfig to use a larger framesize. Also, your switches need to be configured appropriately, but if you can use a 9000 byte MTU, I would recommend it.

Matt

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Matthew Zito
Chief Scientist
GridApp Systems
P: 646-452-4090
mzito_at_gridapp.com
http://www.gridapp.com

-----Original Message-----

From: oracle-l-bounce_at_freelists.org on behalf of goran bogdanovic Sent: Sun 11/18/2007 4:13 AM
To: ujang.jaenudin_at_gmail.com
Cc: rprabha01_at_gmail.com; oracle-l_at_freelists.org Subject: Re: RAC 10.2.0.3  

I can't say how MTU size is managed on HP-UX...but at least AFAIK in Linux should not be an issue, because Linux implements a method known as "path MTU discovery" (if enabled) to determine the MTU on a site-by-site basis. If the initial (or manually adjusted) MTU used for a connection is too high, Linux throttles it back until it works...kind of self optimizing the connection.
Maybe you should speak with your SA to check what is behavior in HP or someone on the list with better HP knowledge can give you more info.

regards,
goran

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http://www.freelists.org/webpage/oracle-l Received on Sun Nov 18 2007 - 20:32:39 CST