Re: network setup question
On Wed, 2010-05-05 at 21:06 -0400, Miles Fidelman wrote:
> Not sure if this is the right list, sort of a general linux networking
> question (pointers to a more appropriate list welcomed)....
> - I have two servers in a datacenter, currently used for different things
> - I have one gigE cable coming in from one of the datacenter's big
> routers - that goes into a simple gigE switch - each box is plugged into
> that switch
> - I have two network /27 network blocks that are NOT contiguous - I use
> one for each box
> - as I understand the basic setup, any traffic from one of my boxes to
> the other (one netblock to the other) end up going to the datacenter's
> router and back (and the traffic gets accounted for in our bill)
> Up to now, I haven't been routing any traffic between boxes, but I'm
> getting ready to install some cluster software and I expect there to be
> a lot of inter-box traffic. So....
> I'm now looking for a way to have the inter-box traffic go directly
> through the gigE switch, and not reach the datacenter's router. Which
> leaves me with some questions that are just a bit beyond my general
> network setup knowledge:
> 1. Yes, I have a cross-over cable plugged directly between the 2nd
> ethernet card in each box. I plan to dedicate that for disk mirroring
> traffic; but I expect I'll end up with things running on one box that
> need to talk to the other, that may go through the primary ethernet ports.
> 2. Is there a way to use ARP and/or set up routing tables so that
> inter-box traffic simply goes through the bridge?
> 3. If not, is this something I can do with a simple Linksys switch/router?
> Any guidance would be much appreciated.
if the 2 servers are in the same ethernet broadcast domain - just
because they are in the same switch doesn't mean they can talk directly
- they could be vlan'ed apart.
Presuming they are then
if server a has ip 192.168.11.10/24 on eth0 - belongs to
and server b has 10.0.0.254/24 on eth0 - belongs to
then what you can do is (iproute package is your friend)
on server A
ip r a 10.0.0.254/32 dev eth0 src 192.168.11.10
on server B
ip r a 192.168.11.20/32 dev eth0 serc 10.0.0.254
that should work for you.
you could add these to post-up instructions in /etc/network/interfaces
> Miles Fidelman
> In theory, there is no difference between theory and practice.
> In<fnord> practice, there is. .... Yogi Berra