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Hello,
On Mon, 7 Aug 2000, Pietro Ravasio wrote:
> Hi!
>
> I'm building an HA cluster based on RedHat/VaLinux 6.2 + piranha/ipvsadm/...
>
> I've got two ethernet cards in each cluster's node, each of them is
> connected to a different switch. For example, on a real web server, they're
Why on different switch? Are eth0 and eth1 on same switched hub?
Connect each host on two hubs. Is that different?
> configured as follows on an 192.168.1.0/24 subnet:
>
> 192.168.1.1 eth0 Link encap:Ethernet HWaddr 00:C0:DF:A0:41:D9
> 192.168.1.11 eth1 Link encap:Ethernet HWaddr 08:00:09:C0:02:84
>
> I've got two real web servers and I would like to use them as they were
> four, letting pulse monitor their 4 IP adresses.
Very good for network oriented services
>
> I've got a problem: I've tried to ping, from another host of my subnet,
> 192.168.1.1 and 192.168.1.11, but everytime I ping both of them, the SAME
> hardware interface replies to me. Infact, launching arp -an:
You have to hide both eth interfaces from each other (in the
real servers):
echo 1 > /proc/sys/net/ipv4/conf/all/hidden
echo 1 > /proc/sys/net/ipv4/conf/eth0/hidden
echo 1 > /proc/sys/net/ipv4/conf/eth1/hidden
I don't expect side effects after applying these commands :)
And before you ask, Yes, the hidden addresses will be replied but
only through the same device :) Be careful with the routing.
>
> ? (192.168.1.1) at 08:00:09:C0:02:84 [ether] on eth1
> ? (192.168.1.11) at 08:00:09:C0:02:84 [ether] on eth0
Yes, for one broadcast ARP request you can expect replies
from many ARP devices if they are connected on same hub.
So, you have to try the above settings or to connect
each eth on different switched hub.
>
> The problem is that if I disconnect the cable of eth1 interface, the server
> doesn't reply anymore, even if it should have the other interface active!
> The other interface starts working only if i "kill" eth1 with "ifconfig
> eth1 down"
I don't think this is forever but if the above commands
work I don't expect such problem.
>
> Is this normal? Is there a way to "statically bind" each mac address to an
> IP address and to have some sort of high availability?
Yes, you can add static MAC entries for both addresses on each
client/router on the LANs. But first try with the hidden flag :) Using
ARP is the preferred way before starting to add static entries on all
hosts!
The high availability can be provided only from the cluster
software. Don't rely on ARP for this.
>
> Thanks,
> Pietro Ravasio
Regards
--
Julian Anastasov <ja@xxxxxx>
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