Clusters replying from same IP address without a NAT?

[klacke@REDACTED]

On Wed, Aug 18, 2004 at 03:39:16PM +0200, Lennart Öhman wrote:
>    A slightly off the topic question...
> 
>    Anyone familiar with the possibility to have a second "hidden"
>    IP address associated with a physical network interface in
>    Solaris style UNICIES. Hidden in the sence that it does not
>    answer ARP questions, in order to not confuse routers since I
>    plan to have several such hidden interfaces on the same network
>    with the same IP address.


The way to go about this in linux is to use a dummy interface,

[root@REDACTED]~ > modprobe dummy

[root@REDACTED]~ > ip addr add 1.2.3.4 dev dummy0

[root@REDACTED]~ > ip addr show
1: eth0: <BROADCAST,MULTICAST,NOTRAILERS,UP> mtu 1500 qdisc \
          pfifo_fast qlen 1000
    link/ether 00:0a:e6:6c:f2:96 brd ff:ff:ff:ff:ff:ff
    inet 217.209.73.25/24 brd 217.209.73.255 scope global eth0
2: lo: <LOOPBACK,UP> mtu 16436 qdisc noqueue 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
3: eth1: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:50:22:39:00:76 brd ff:ff:ff:ff:ff:ff
    inet 192.168.128.1/24 brd 192.168.128.255 scope global eth1
    inet 192.168.128.2/24 brd 192.168.128.255 scope global secondary eth1:0
4: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop 
    link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
    inet 1.2.3.4/32 scope global dummy0



This way, packets destined to 1.2.3.4 which goes through this box, 
(somehow, either because the box is inline, or packets get REDIRECTED
to it) will be terminated on the box and not routed further.


Solaris, I know nothing about, but I bet it works pretty similar.


/klacke




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