Re: Two (2) IP and hostnames on same NIC

From: Green, Simon (Simon.Green_at_EU.ALTRIA.COM)
Date: 05/19/04

  • Next message: Holger.VanKoll_at_SWISSCOM.COM: "hmc terminals" 
    Date:         Wed, 19 May 2004 11:11:44 +0200
To: aix-l@Princeton.EDU

    The simplest way, if you just want the NIC to respond to both IP
    addresses, is to use an alias.
    ifconfig en0 10.11.12.13 netmask 255.255.255.0 alias
    Or use smit, which will let you put it into the ODM.
    We use aliases a lot for our home-grown BCS.

    One thing to remember is that out-bound traffic goes out on the
    primary address, not any of the aliases. If that's not what you
    want you'll need a different approach.

    We had a weird problem with a NIC that had a lot of aliases on,
    (about 20, iirc), which messed up the default route.

    You also need to take some care with the subnets and routing. For
    example, if you have two physical networks, 10.* and 193.*, say.
    If you add an alias on the 10 network to a NIC which is physically
    on the 193 network any packets coming from the box on the 193
    network destined to the 10 network will NOT get sent to the default
    router, because IP will think that the destination address is on the
    local network.

    The safest thing is to only use aliases which are in the same
    subnet as the NIC to which they are being added. 

    --
Simon Green
Altria ITSC Europe Ltd
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> -----Original Message-----
> From: cbaker@GOODYEAR.COM [mailto:cbaker@GOODYEAR.COM]
> Sent: 18 May 2004 21:17
> To: aix-l@Princeton.EDU
> Subject: Two (2) IP and hostnames on same NIC
>
>
> How do you define two (2), or more, IP addresses and
> hostnames to the same NIC?   This is AIX 5.2.
  • Next message: Holger.VanKoll_at_SWISSCOM.COM: "hmc terminals"

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