How to set my Linux machine to have two network cards with two IPs - Networking

This is a discussion on How to set my Linux machine to have two network cards with two IPs - Networking ; Dear all gurus out there, I am newbie to Linux and networking. I have a Red hat linux that used as a Database machine, oracle. I have 2 network cards that I wish to set to 192.168.0.10 and 192.168.0.11 respectively, ...

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Thread: How to set my Linux machine to have two network cards with two IPs

  1. How to set my Linux machine to have two network cards with two IPs

    Dear all gurus out there,

    I am newbie to Linux and networking.

    I have a Red hat linux that used as a Database machine, oracle.

    I have 2 network cards that I wish to set to 192.168.0.10 and
    192.168.0.11 respectively, the default gw is 192.168.0.1. The
    connection of the two IPs coming from 2 different switches (still from
    the same router).

    My purpose is that : if one of the switches is down, my connection
    still up with the other side.

    I know switch is hardly "down", but i wish to have full redundancy.

    What I did is, I jus set the 2 network cards with the two IPs and I
    switch off one of the switches, "poof" the whole network
    down..........so, how can it be done ?

    Or any other alternatives ?


    Thanks.


  2. Re: How to set my Linux machine to have two network cards with two IPs

    On Sun, 27 May 2007 02:02:58 -0700, keanewoon wrote:

    [link failover]

    > Or any other alternatives ?


    Try the 'bonding' driver:
    http://linux-net.osdl.org/index.php/Bonding

    And use an interface alias if you still need the second IP adress, e.g.:
    ifconfig bond0:1 ...

    --
    -Menno.


  3. Re: How to set my Linux machine to have two network cards with two IPs

    In article <1180256578.345257.44170@d30g2000prg.googlegroups.c om>,
    wrote:
    >Dear all gurus out there,
    >
    >I am newbie to Linux and networking.
    >
    >I have a Red hat linux that used as a Database machine, oracle.
    >
    >I have 2 network cards that I wish to set to 192.168.0.10 and
    >192.168.0.11 respectively, the default gw is 192.168.0.1. The
    >connection of the two IPs coming from 2 different switches (still from
    >the same router).
    >
    >My purpose is that : if one of the switches is down, my connection
    >still up with the other side.
    >
    >I know switch is hardly "down", but i wish to have full redundancy.
    >
    >What I did is, I jus set the 2 network cards with the two IPs and I
    >switch off one of the switches, "poof" the whole network
    >down..........so, how can it be done ?
    >
    >Or any other alternatives ?
    >
    >
    >Thanks.
    >


    Google bonding network interfaces...

    You need to have one ip address that is on both switches and will move
    from a primary to a seconday NIC.

    Intel had it's own IANS software on the older Linux versions but is now
    supporting standard bonding. On the 2.4 the Intel stuff was nice but
    required at least one Intel NIC per bonded pair.

    Bill

    --
    "When I think back on all the crap I learned in Vax school
    It's a wonder I fixed anything at all." (to the tune of Kodachrome)
    pechter-at-gmail.com

  4. Re: How to set my Linux machine to have two network cards with two IPs

    William Pechter wrote:

    > In article <1180256578.345257.44170@d30g2000prg.googlegroups.c om>,
    > wrote:
    >>Dear all gurus out there,
    >>
    >>I am newbie to Linux and networking.
    >>
    >>I have a Red hat linux that used as a Database machine, oracle.
    >>
    >>I have 2 network cards that I wish to set to 192.168.0.10 and
    >>192.168.0.11 respectively, the default gw is 192.168.0.1. The
    >>connection of the two IPs coming from 2 different switches (still from
    >>the same router).
    >>
    >>My purpose is that : if one of the switches is down, my connection
    >>still up with the other side.
    >>
    >>I know switch is hardly "down", but i wish to have full redundancy.
    >>
    >>What I did is, I jus set the 2 network cards with the two IPs and I
    >>switch off one of the switches, "poof" the whole network
    >>down..........so, how can it be done ?
    >>
    >>Or any other alternatives ?
    >>
    >>
    >>Thanks.
    >>

    >
    > Google bonding network interfaces...
    >
    > You need to have one ip address that is on both switches and will move
    > from a primary to a seconday NIC.


    Follow on from this:

    Caveat: I have only done bonding with 802.3ad for the purposes of link
    aggregation (enhanced bandwith), not for failover.

    I agree that bonding is probably the neater solution (only ever have one IP)
    and I believe that a suitable way would be to use the arp monitoring
    failover mode in the linux bonding module. Wanring though: don't just set
    up a bonded link in aggregation mode willy nilly or there is going to be
    much network weirdness resulting (arp confusion for one). The "ultimate"
    documentation can be found in the linux source here:

    linux/Documentation/networking/bonding.txt

    To the OP - when you have a solution, I would recommend that you test it
    thoroughly with 2 tcpdump sessions bound each to one NIC and see if it is
    really behaving as you expect. Link aggregation requires support from the
    switch infrastructure and I've never come across link aggregation working
    where the links feed two different switches. Failover should howvere work
    with any kit, though you might get a pregnant pause when the primary link
    fails and the switches have to re-discover the path, but that shouldn;t be
    more than a few seconds IME.

    Cheers

    Tim



  5. Re: How to set my Linux machine to have two network cards with two IPs

    hi,
    this configuration is not a linux issue your configuration is fine
    but will not support your target to make a fail over
    to make the data base client to use both IP's configure the client
    side
    tnsnames.ora to fail over the other IP if one faild
    the 2nd and the most important is the however your connection
    will be established again but you will loose your session
    to avoid such issue you should use a caching library in your code
    (application) such as oci or jdbc.
    one more thing if you really want to make complete redundant use RAC
    configuration
    as the instance is more critical than the switch


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