Re: Problems recognizing director

[Jason Wies <jason@xxxxxx>]

On Sat, Feb 16, 2002 at 04:22:57PM +0000, Julian Anastasov wrote:
> Postulate #2: Hiding addresses with the hidden flag
> 
>       hidden.txt has the needed information:
> 
> Never configure shared IP address (hidden VIP) before preconfiguring
> the used network interface for this.
> 
>       The problem is that if the address is added before
> fully setting the hidden flags for the used device and in the
> all/ section we risk to answer ARP probe(s) for this shared IP
> address before the things are successfully configured. If
> your rc.d services start too slowly and other hosts on the
> LAN probe for VIP on each second they will receive the
> wrong answer before the hidden flags are set later at boot.
> 
>       So, the order is (I don't know what the distros do):
> 
> - configure the device for IP (this step allows we to set any
> flags for this device later)
> 
>       ifconfig DEV 0.0.0.0 up
>       or
>       ifconfig DEV RIP up
> 
> - configure all needed device flags before adding addresses and
> routes that will lead this device to receive and send traffic
> 
>       for i in all dummy* lo # what you need
>       do
>               echo 1 > $i/hidden
>       done
> 
> - configure the addresses and routes
> 
>       ip addr add VIP1 dev lo [scope host]
>       ip addr add VIP2 dev dummy0 [scope host]
>       ip addr add VIPNET1/24 dev lo [scope host]

Thank you Julian, very helpful!  For reference, here is what I ended up using:

Real servers
------------
Only RIP device in /etc/network/interfaces.  This is run at boot time:

ifconfig dummy0 0.0.0.0 up

echo 1 > /proc/sys/net/ipv4/ip_forward
echo 1 > /proc/sys/net/ipv4/conf/all/hidden
echo 1 > /proc/sys/net/ipv4/conf/dummy0/hidden

ifconfig dummy0 66.xxx.xxx.119 netmask 255.255.255.240 broadcast 66.xxx.xxx.127 
up

Director
--------
This in /etc/network/interfaces, nothing extra at boot:

iface eth0 inet static
        address 66.xxx.xxx.118
        netmask 255.255.255.240
        network 66.xxx.xxx.112
        broadcast 66.xxx.xxx.127
        gateway 66.xxx.xxx.113

iface eth0:0 inet static
        address 66.xxx.xxx.119
        netmask 255.255.255.240
        network 66.xxx.xxx.112
        broadcast 66.xxx.xxx.127
        gateway 66.xxx.xxx.113

So very straightforward after I got the concepts straight.  The real servers 
and director have been rebooted multiple times to test, and they always come 
back up ready to serve.

Thanks again,
Jason Wies