routing problem

From: Sippel, Christian (Christian.Sippel_at_IZB.DE)
Date: 07/29/03

  • Next message: Green, Simon: "Re: How can use two 7204 for redundance in HA environment?" 
    Date:         Tue, 29 Jul 2003 11:00:02 +0200
To: aix-l@Princeton.EDU

    Dear list,
    I have the following routing problem:

    An AIX 5.1-Box has 2 IP adresses in the same subnet, 172.16.125.121 and
    172.16.125.123. Both are on the same adapter, en0, .121 als "real" adress,
    .123 as an alias. I would like to send mails to an Exchange-Server with the
    IP 1.4.13.29 which is behind a firewall. If I do for example a traceroute to
    1.4.13.29 my box uses its .121-adress.

    I tried the following
     route add -host 1.4.13.29 -interface 172.16.125.123

    then netstat -rn tells me:

    Routing tables
    Destination Gateway Flags Refs Use If PMTU Exp
    Groups

    Route Tree for Protocol Family 2 (Internet):
    default 172.16.125.97 UG 10 2347933 en0 - -
    1.4.13.29 172.16.125.123 UH 0 44 en0 - -
    127/8 127.0.0.1 U 7 828343 lo0 - -
    172.16.125.96/27 172.16.125.123 U 2 1889714 en0 - -
    172.16.125.121 127.0.0.1 UGHS 5 12027 lo0 - -
    172.16.125.123 127.0.0.1 UGHS 4 12036 lo0 - -
    172.16.125.128/25 172.16.125.143 U 7 1592778 en1 - -
    172.16.125.143 127.0.0.1 UGHS 42 2070163 lo0 - -

    a traceroute says

    # traceroute 1.4.13.29
    trying to get source for 1.4.13.29
    source should be 172.16.125.123
    traceroute to 1.4.13.29 (1.4.13.29) from 172.16.125.123 (172.16.125.123), 30
    hops max
    outgoing MTU = 1500
     1 * * *
     2 * * *
     3 * * *
     4 * * *
     5 *

    but with iptrace I can see that my box doesn't send anything at all - it
    behave as if it would miss a route. Also the Firewall-guys tell me nothing
    is received by the firewall.

    I'm guessing my box "thinks" it could reach the destination IP 1.4.13.29
    via a local interface and then sends ARP-Requests for the 1.4.13.29 which
    aren't forwarded by the firewall - but I'm not shure about what's going on.

    So how can I tell my box if it wants to reach 1.4.13.29 to use it's
    sender-IP .123 and the default gateway?

    Any help is really appreciated, thanks a lot,

    Christian

  • Next message: Green, Simon: "Re: How can use two 7204 for redundance in HA environment?"

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