13.26 TCP Load Distribution IP alias question

In this TASK gets translated to thru .3 in a rotary fashion.


My question is : Why didn't R5 create an IP alias for the automatically like R5 has been doing in previous tasks.

This task has us do it manually with the ip alias command


What changed here?  I cant seem to wrap my mind around this and would appreciate any spoon feed.



Thank you




  • I've ran into your same question.

    The documentation in this case tells that automatic aliasing occur on inside global or outside local pools or static entries as long as those address consist on attacched subnets:


    a NAT pool used as an inside global or outside local pool consists of
    addresses on an attached subnet, the software will generate an alias for
    that address so that the router will answer ARPs for those addresses.

    automatic aliasing also occurs for inside global or outside local
    addresses in static entries. It can be disabled for static entries can
    be disabled by using the "no-alias" keyword:.


    What i think happened here is that our rotary pool is on the inside local side and not on inside global side so maybe for that reason the automatically aliasing entry is not automatically created. After issue the sh ip nat translation you will see that inside global is address so until we don't create an alias for that addrress the translation won't be successful.

    This is the only explanation i could gave to myself since i didnt found nothing better. But i will lab it more to better confirm it.

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