HMC

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  • 1.  HMC RMC and NAT IP address

    Posted Tue January 24, 2023 08:25 AM
    Edited by Per Hillerström Tue January 24, 2023 09:42 AM

    So, regarding HMC and RMC …

    I know HMC do not support NAT with RMC but have anyone here found a work-around for this and perhaps solved it anyway without remove NAT?

    https://www.ibm.com/support/pages/fixing-no-rmc-connection-error "Network Address Translation (NAT) is not supported in HMC RMC domains and NAT would need to be disabled on the network".

    Just to explain about the network traffic:

    LPAR can successfully send RMC 657 traffic via NAT IP address to the HMC server but the HMC respond to the actual LPAR IP address instead of NAT IP address and that is not allowed.



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    Per Hillerström
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  • 2.  RE: HMC RMC and NAT IP address

    Posted Wed January 25, 2023 04:34 AM
    I would expect HMC to get info on RMC partner address from the RMC protocol data, not from the TCP/IP headers. That means NAT would not be successful unless the device doing NAT understands RMC protocol and performs necessary "fixups" in PDU (on RMC protocol level).

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    Lech Szychowski
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  • 3.  RE: HMC RMC and NAT IP address

    IBM Champion
    Posted Wed January 25, 2023 06:01 AM
    If the issue is an IPv4 collision, you can configure IPv6 which is big enough to never need NAT.

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    José Pina Coelho
    IT Specialist at Kyndryl
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  • 4.  RE: HMC RMC and NAT IP address

    Posted Wed January 25, 2023 06:59 AM
    Nice idea, but I think that would affect many more nodes since the end customer have +200 nodes with that subnet.

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    Per Hillerström
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  • 5.  RE: HMC RMC and NAT IP address

    IBM Champion
    Posted Wed January 25, 2023 08:52 AM
    Hi Per,

    I have good news for you. It is officially supported now and was delivered last month:

    https://ibm-power-systems.ideas.ibm.com/ideas/AIX-I-232

    Unfortunately I can't provide more information right now because I still didn't test it. But may be @HARIGANESH MURALIDHARAN can help with it?


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    Andrey Klyachkin

    https://www.power-devops.com
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  • 6.  RE: HMC RMC and NAT IP address

    Posted Wed January 25, 2023 09:10 AM
    Awesome! Then I "just need to upgrade" customer AIX ... that shouldn't be that difficult to get approved. :D

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    Per Hillerström
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  • 7.  RE: HMC RMC and NAT IP address

    Posted Thu January 26, 2023 01:05 PM
    Hi Per

    Note that according to what is written in the comments in https://ibm-power-systems.ideas.ibm.com/ideas/AIX-I-232 , you also need HMC level 1040 - that is not available yet.

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    Janus Hertz
    Consulting IT Specialist
    IBM Technology Services
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    Janus Hertz
    Consulting IT Specialist - Power Systems / IBM i - Virtualization, Security, HA
    IBM
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