We're having a *very* odd problem with ARP broadcasts. I hope someone here
can help.
We run IBM Network Dispatcher for muxing our webservers. Part of the
required setup is that each machine in a cluster must have an IP alias of
the cluster set to its loopback address.
For example, if 10.1.10.8 were the cluster IP, each machine that was part
of that cluster would have to have the following entry in the ifconfig
tables:
lo:0 Link encap:Local Loopback
inet addr:10.1.10.8 Mask:255.255.255.255
UP LOOPBACK RUNNING NOARP MTU:3924 Metric:1
The actual cluster IP resides on the machine running Dispatcher.
The problem is that, regardless of the "NOARP" setting on the loopback
and its alias(es), somehow the machine occassionally broadcasts its MAC
address for its interface to the net as the origin for the cluster IP,
thereby usurping the mux machine.
For example, using the above, if 10.1.10.15 had the following interface:
eth0 Link encap:Ethernet HWaddr 00:90:27:42:90:7B
inet addr:10.1.10.15 Bcast:10.1.10.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:577035 errors:0 dropped:0 overruns:0 frame:0
TX packets:291254 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
Interrupt:18 Base address:0x4000
At some point, the router and/or a couple of machines would end up with
the following arp entry:
(10.1.10.8) at 00:90:27:42:90:7B
Despite the fact that that IP belongs to a different machine, the arp entry
points to a machine which only has the IP as an alias on its loopback
interface.
The question is, then:
What is the best way to fix this? Is there some patch that needs to be
applied to the kernel, or a I missing a parameter to ifconfig somewhere?
Please reply to me directly (or at least include me in a CC list), as I do
not subscribe to this list.
Thanks.
===================================================
Joe Lizzi SysAdmin
[EMAIL PROTECTED] Advance Internet
201-459-2826
-
To unsubscribe from this list: send the line "unsubscribe linux-net" in
the body of a message to [EMAIL PROTECTED]
