You can do this with a RSM in the catalyst 5xxx. However if you just
want the switch to do this, I don't think that your going to like the
answer. First of all, the switch itself isn't going to be your
problem. The switch doesn't care about IP addresses. It's only really
concerned with MAC addresses. That said, if your hosts would address
everything to it's proper MAC address when sending frames out, the
switch would deliver it just fine. However, unless all of the hosts
are with the same network (or have secondary addresses, but this still
causes you to "renumber") they won't have a MAC address for the
destination outside of it's network (or subnet) and will send to it's
default address (both MAC and IP).
An example:
If I have a host 192.9.200.1/24 and it's connected somehow to a router
192.9.200.254/24 through a Cat or whatever. Then I will have the
address of 192.9.200.254 in my ARP table. When I want to send traffic
to 192.9.200.254, an ethernet frame will have the MAC address of the
192.9.200.254 host as it's destination. I will also be able to send
traffic to any other host in the 192.9.200.0/24 network without a layer
three router. However, if I don't have the MAC address of a
destination (say 192.9.204.1/24) then I will have to forward the frame
to the default address (the router) and let it make a forwarding
decision be made. If the other network is connected to the router,
then the router would have a MAC address for the destination in it's
ARP table and would forward the packet accordingly. That's what the
RSM would do for you.
Or you could simply change all of your /24 networks in a larger
aggregate (like a /21 or something) but it's just as much work as
renumbering and your topology may not even make it feasible.
Summary: If you have the money, Cisco has a way ;)
Barry
> Hi,
> this is probably a fairly basic question for some people used with
> switching but I'm having a lot of trouble on finding documentation
> answering my questions.
> Anyways here's my question. We're looking at implementing a
> Catalyst switch on our LAN and create VLANs. However, there are two
> subnets on that network we'd like to put on the switch (let's say network
> 192.9.200.0 and 192.9.204.0) since we'd like to avoid readdressing. How
> can I route between these two subnets?
> Will the Catalyst be able to do that for me? Or do I have to use a
> separate router.
> If it's not available right now, when should it be?
>
> Thank you very much,
>
> Pierre-Etienne Chartier
>
>
> >+=+=+=+=+=+=+=+=+=+=+=++=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+==+=<
> > If there was an information revolution, it's over: <
> > information won. <
> > -Diana Lady Dougan <
> >--------------------------------------------------------------------<
> >Pierre-Etienne Chartier <
> >Systems Analyst, Logibro, inc. <
> >+=+=+=+=+=+=+=+=+=+=+=+=++=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+<
>
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