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  • 1.  Changing a TCP route

    Posted 08/23/23 09:43 AM

    I have a DMZ lpar which supports multiple interfaces (IP addresses).

    Many IBM i products do not "bind specific".  I want to ensure that all communication between this DMZ lpar and our Safe Guarded Copy lpar is only on one of these interfaces.  If it wasn't for BRMS I'd have no comm going to this SGC lpar.

    DMZ lpar:

    Internet address:  208.xxx.xxx.xxx

    subnet:  255.255.255.0

    SGC lpar:

    Internet address:  10.yyy.yyy.yyy

    subnet:  255.255.254.0

    I'm thinking it's as easy as:

    ADDTCPRTE RTEDEST('10.yyy.yyy.yyy') SUBNETMASK('255.255.254.0') NEXTHOP('208.xxx.xxx.1') BINDIFC('208.xxx.xxx.xxx') TEXT('Route for BRMS to SGCTLKIT')    

    But I remember trying to deal with the concept of Schowler routes years ago and that experience left me cautious about dealing with routes.

    Also, on ADDTCPRTE, do you enter the subnetmask of the source or the destination?  I think it's the destination.



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    Robert Berendt IBMChampion
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  • 2.  RE: Changing a TCP route

    Posted 08/24/23 07:15 AM

    Standard routing decisions are based on destination.

    So yes, it is the subnetmask of the destination, otherwise wouldn't make sense.

    I don't know what a "Schowler route" route is, never heard such term in networking (maybe IBM specific?), maybe are you referring to Equal Cost Balancing/Routing?

    BTW, it is possible in networking do routing decisions based on different variables, normally one uses routers for that (Policy Based Routing).

    Anyway, the particular sending software decides the source address of the packet and interface, the standard routing stack rule just act on the destination address.



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    --ft
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  • 3.  RE: Changing a TCP route

    Posted 03/31/25 08:16 AM

    Ace, see Schowler Routes on the IBM iSeries. And no, that is not standard networking terminology. It's an IBM i thing only:



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    Kurt Thomas
    Senior System Engineere
    Fortra
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    Original Message


  • 4.  RE: Changing a TCP route

    Posted 08/24/23 11:44 AM

    Hello Robert,

    You're right, creating the route indicating the preferred interface should be enough.

    And you must indicate the targe subnet mask in the definition.

     

    Best regards

     

     

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    Andreu Rul

    CTO

    Telf: +34 663 817 144

     

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  • 5.  RE: Changing a TCP route

    Posted 08/24/23 03:48 PM

    Thats enough. Just remember to validate the subnet masking.



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    Juan Martin Araya Carrasco
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  • 6.  RE: Changing a TCP route

    Posted 03/31/25 11:02 AM

    Hi Robert,

    If there is only one host to be access by the IBM i you can use the *HOST parameter in SUBNETMASK. option

    Regards

    Virgile



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    Virgile VATIN
    Head of IT Infrastructure
    DRP SOFTWARE
    Avelin
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