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RE: dualing routers [7:84161] posted 02/11/2004
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On Wed, 11 Feb 2004, Priscilla Oppenheimer wrote:
> Karyn Williams wrote:
> > 
> > At 01:14 AM 2/11/04 GMT, you wrote:
> > >Yes, that's very workable and a good idea. You can connect the
> > two routers via an Ethernet cross-over cable. Another 1721 would work
> > The 1721 has only one ethernet port but slots for multiple wan
> 
> If you could add an Ethernet interface that would be faster. Isn't there a
> WIC-1ENET for the 1721?
> 
> Serial will be sort of slow. I don't think you can clock the serial
> interface on a 1721 any faster than 2 Mbps. But that might be OK,

2 Mbps would be OK in this case. The traffic
from these wireless users should never go onto the administrative
network. The wireless is for public visiting the space who want to check
their offsite e-mail or have an urge to surf the web while attending a
performance at our theatre. That makes the bottleneck the
frame connection at 1.54Mbps. But then someone will want to print ...

If I can get an ethernet mod for the open slots I will
probably use that instead.

> For back-to-back routers using serial you need a crossover WAN cable, aka
> DTE/DCE cable. One router will do clocking. Tons of places sell them
because
> they are so popular for lab networks.
> 
> Last time I needed to get them I got them from here and was satisifed with
> the quality, shipping, etc. And I notice the price has come down!
> 
> http://store.yahoo.net/chipsettech/dtedsercrosc.html
> 
> If you start a thread asking the best place to buy WAN DTE/DCE crossover
> cables, you'll probably get tons of options.
> 
> You could make your own too. There are specs for that somewhere but I can't
> find them. I think most people buy them.
> 
> Good luck with the project. I think you are absolutely doing the right
> thing. Some people separate wireless users with VLANs, but I like your
> approach better.....
> 
> Priscilla

Thank you and thanks for your help. 
 
> > trying to spec out the second router, the second switch will be
> > a 2950C-12.
> > So, since the 1721 has only one ethernet port each, I will have
> > to connect
> > the routers over one of their serial interfaces, therefore the
> > cable
> > question. 
> > 
> > >A few things to keep in mind:
> > >
> > >The wireless users will now be in a different subnet,
> > presumably. In fact
> > >you would probably want to make sure that they are in a
> > different subnet
> > >because that will make it easier to set up ACLs to protect
> > other networks
> > >from those users. The wireless users will have a new default
> > gateway too, of
> > >course.
> > 
> > Absolutely.
> > 
> > >Do they get their address and gateway from a DHCP server? It
> > will need to be
> > >configured to know about the new subnet. If the server isn't
> > local, you'll
> > >need a helper address.
> > 
> > I may have to run that on the second router (dhcp and nat) for
> > the wireless
> > users only. 
> > 
> > >The two routers will need to run a routing protocol, or better
> > yet, use
> > >static routing. The current router will need to have a route
> > back to the
> > >wireless users.
> > 
> > I use static routing whenever I can.
> > 
> > >If I misunderstood or over-simplified, just let me know.
> > 
> > >Priscilla
> > >
> > >Karyn Williams wrote:
> > >> 
> > >> administrative network ---- sw ------------- router
> > >> ------------internet
> > >>                                                |
> > >> wireless access points ---- sw ------------- router
> > >> 
> > >> Is this workable ? Can it be done using a Cisco 1721 and
> > >> something similar
> > >> ? Another 1721 ? What kind of cable would I need to connect
> > the
> > >> routers ?
> > >> 
> > >> Why ? To keep the users on the wireless side from taking down
> > >> the router
> > >> the admin network is using ala nachi. Tips, pointers, gotchas
> > >> welcome. TIA.
> > 
> > -- 
> > 
> > Karyn Williams
> > Network Services Manager
> > California Institute of the Arts
> > karyn@xxxxxxxxxxx
> > http://www.calarts.edu/network
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