HMC

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  • 1.  HMC VMI connection to different LAN IP then HMC IP

    Posted Fri March 31, 2023 09:03 AM

    We recently got 4 new Power 10 systems with a new vHMC 10.2  We setup the vHMC with no issue and connected them to two Power 10 systems in our backup data center that the vHMC is in.  However when we attempt to connect the vHMC to the other two Power 10 systems in our other data center the initial connection connects and gathers information like system name model and such but the the state no connection and will flash (Virtual Management Interface IP is not Reachable)  Does anyone know can the VMI port not connect to power systems the system is on a different LAN then the HMC.



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    Joshua Burton
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  • 2.  RE: HMC VMI connection to different LAN IP then HMC IP

    Posted Fri March 31, 2023 09:10 AM

    Hi Joshua,

         VMI has 2 interfaces that HMC can connect to like FSP/BMC has 2 ports for HMC connection. You can configure the VMI interface such that the vHMC in your backup data center can connect to the VMI , similar to how IP is configured on BMC on the systems in the other data center. VMI IP can be configured from the HMC itself.  Hope this helps. 

    Thanks. 



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    Hariganesh Muralidharan
    Cognitive Systems Management Architecture
    IBM
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  • 3.  RE: HMC VMI connection to different LAN IP then HMC IP

    Posted Fri March 31, 2023 09:35 AM

    I get the different connection but if not the same LAN if they still connect. Here is an example of what we see

    HMC IP VMI IP System Power 10 IP Location P10
    vHMC in data center 1 10.1.1.5 10.1.1.10 System A 10.1.1.25  Data Center 1 Works 
    vHMC in data center 1 10.1.1.5 10.1.1.11 System B 10.25.1.25  Data Center 2 Doesn't


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    Joshua Burton
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  • 4.  RE: HMC VMI connection to different LAN IP then HMC IP

    Posted Tue April 04, 2023 10:38 AM

    This is typical of a routing issue.  My guess is that the Power system in data center 2 does not have the correct gateway set to be able to communicate to systems on a different network.

    To correct, you will need to use a system on the 10.25.1 network (local to your System B) to connect to the ASMI interface (https://10.25.1.25) and change the gateway (or maybe subnet mask) for that system.

    Another possibility is the same sort of configuration problem (subnet mask or gateway) on the HMC, or a firewall.



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    Vincent Greene
    IT Consultant
    Technology Expert labs
    IBM
    Vincent.Greene@ibm.com


    The postings on this site are my own and don't necessarily represent IBM's positions, strategies or opinions.
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  • 5.  RE: HMC VMI connection to different LAN IP then HMC IP

    IBM Champion
    Posted Wed April 05, 2023 05:53 AM

    Hi
    HMC and VMI must reside in different VLANs and of course different Subnet....this is something we found out when we did PoC of P10 with the HMC Code....so change and it will work 
    thx
    vince



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    Vincencio Michaelis
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  • 6.  RE: HMC VMI connection to different LAN IP then HMC IP

    IBM Champion
    Posted Thu April 06, 2023 04:39 AM

    Hi Vince,

    I have both private HMC and VMI addresses in one VLAN and with IPs from the same network assigned by DHCP:

    > lssysconn -r all | grep '9043-MRX\*SERIALNO'
    resource_type=sys,type_model_serial_num=9043-MRX*SERIALNO,sp_type=ebmc,ipaddr=172.16.222.43,user_name=admin,alt_ipaddr=unavailable,state=Connected,vmi_ipaddr=172.16.222.46,vmi_state=Connected
    
    > lssysconn -r vmi -m 9043-MRX*SERIALNO
    resource_type=vmi,type_model_serial_num=9043-MRX*SERIALNO,interface=eth1,ipv4addr=192.168.240.11,gateway=0.0.0.0,net_mask=255.255.128.0,ipv4addr_orig=dhcp
    resource_type=vmi,type_model_serial_num=9043-MRX*SERIALNO,interface=eth0,ipv4addr=172.16.222.46,gateway=0.0.0.0,net_mask=255.255.0.0,ipv4addr_orig=dhcp
    


    As you can see they're both in 172.16.0.0/16.

    To be honest - it is HMC V10R2M1040 (beta). But I don't remember any problems with earlier HMC V10 releases.



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    Andrey Klyachkin

    https://www.power-devops.com
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  • 7.  RE: HMC VMI connection to different LAN IP then HMC IP

    Posted Thu April 06, 2023 11:21 AM

    I can see that the VMI has no gateway configured, and is on a DHCP served address with a 172.16/16 network.  The second HMC in another data center will only be able to communicate with that on a "stretched" VLAN, for example Cisco OTV or ACI stretched network. 

    Can the two HMCs ping each other on a 172.16 address?  That is a pretty simple troubleshooting step to see if they actually are on the same network.

    Are you using multiple HMC ports on the Power10 systems, or one address on one port for each?

    Bottom line, if they are not on the same network, you are going to need a gateway address or a stretched configuration.  Talk to your network team.






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    Vincent Greene
    IT Consultant
    Technology Expert labs
    IBM
    Vincent.Greene@ibm.com


    The postings on this site are my own and don't necessarily represent IBM's positions, strategies or opinions.
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