[asterisk-users] [Asterisk-users] asterisk +heartbeat (Wilton Helm)

[Steve Totaro]

On Fri, Oct 17, 2008 at 4:17 AM, Freddi Hansen <fh at danovation.dk> wrote:
>>
>>> having two NICs on the same subnet
>>
>> I'm trying to wrap my brain around that in the larger network
>> picture.  Two
>> NICs in the same subnet (presumably on the same computer) would have
>> access
>> to the same other devices.  This could potentially increase bandwidth
>> (maybe?) and offer redundancy (if NICS, wiring or switches were the
>> biggest
>> source of failure).  I'm not sure how the OS would decide which one to
>> use
>> for a given packet, or if an application (such as Asterisk) could
>> determine
>> which one to use.  I can see potential problems with addressing, as other
>> devices could send to one, and would definitely not know what to do
>> with a
>> reply from the other, etc.  I'm not sure this would be an Asterisk bug.
>> Without some concept of what I am missing here, I would consider it a
>> cockpit error on system setup.  The only reason I can think of for having
>> two NICs in a computer would be using it as a router--in which case they
>> wouldn't be on the same subnet.  (OK I've done it before for redundant
>> paths, but again, the paths should be on different subnets, otherwise how
>> does one tell the OS which path was intended?)
>
> Try reading:
> http://www.linuxfoundation.org/en/Net:Bonding
> We have 3 networks on each of our servers. Each network (and IP) is
> served by 2 nics. (yes 6 nics per server)
> Works well with Asterisk, you can disconnect cables or take power from
> one of the core switches without as much as a click  in audio in ongoing

I have mutihomed boxen on many different networks as well, this has
never been an issue.

Let's put aside why would you or there is no reason, and then think
about it again.  Let's just say you wanted two NICs on the same subnet
with different IPS,  Is it a bug or by design?

I am fully aware of aggregated (bonding) of links too.

I didn't bother to click the link because I assume it is just plain
old network bonding (aggregating) like in the Cisco world, you can
bond several NICs and get higher bandwidth on a switch, I have three
NICS bonded for a three gigabit uplink and that material is too dry
for this morning, and if it is what I think it is, I have been doing
it for years, let's see I got my CCNA in 97 and renewed sometime or
another....

Cisco calls this Multiliink in the router space..  I had three bonded
T1s, I could unplug up to two of the T1s and and the internet stayed
up up, just at 33% capacity.

I am talking about NICs with different IPs on the same subnet.  Is
Asterisk or Linux deciding to reply to a packet sent to 10.0.0.1
(eht0) by sending that packet through 10.0.0.254?

-- 
Thanks,
Steve Totaro
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