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When enabling path MTU discovery, what value should be assigned to PMTUD?

Technote (FAQ)


Question

I am trying to enable Path MTU discovery for IPv4.

What I cannot figure out or find information on is what to change the VTAM start option PMTUD TCPVALUE to. I thought it was a YES NO setting. After reading more, I see it states it needs to be some sort of TCPVALUE.

What should the TCPVALUE be?

Answer

The value you need to specify for PMTUD is the TCPVALUE keyword, not a specific number. TCPVALUE is the default value of PMTUD. The keyword TCPVALUE "Indicates that VTAM accepts the TCP/IP stack (associated with EE) setting to control path MTU discovery for both IPv4 and IPv6 EE connections."

Document information

More support for: z/OS Communications Server

Software version: 1.11, 1.12, 1.13, 2.1

Operating system(s): z/OS

Reference #: 1596736

Modified date: 2013-04-24