[TriLUG] OT: Bridge/Advanced routing
jonc at nc.rr.com
Fri Jul 1 20:00:01 EDT 2005
I don't know exactly what you want but I set these types of scenarios
all the time. I generally run two different private networks off of the
E0 and E1 interfaces respectfully. At that point it's trivial to set up
routing between the two networks.
I would setup two default routes on the 2621: one that goes out the T1
interface and a second failover that points to the cable modem. If your
T1 goes down, then your traffic goes out the cable modem. Of course
this only helps with your NAT-ted traffic and won't help with your
hosted services (though you could easily setup a secondary Mail address
that comes in via the cable modem).
I know some folks that actually bridge on these Cisco's and I've seen
some interesting setups for that - though in most cases routing should
work just fine.
good Luck - Jon Carnes
(BTW, OpenBSD would bridge these networks just fine... :-)
On Thu, 2005-06-30 at 16:32, Steve Hoffman wrote:
> I'm sorry to stray off topic here, but this could end up being on
> topic in the end. I've got a cisco 2621 router with a t1 card and two
> ethernet ports running on a t1; additionally I have Time Warner
> business class cable modem service.
> We like to have at least two networks for redundancy (just in case)
> but rather then one sitting idle all the time I'd like to create a
> development network and a rest of the company network but bridge the
> two so that requests for machines on one network or the other don't go
> out to Atlanta and back when they could just as easily stay inside the
> I thought our cisco router would be able to do that just fine..but
> apparently it can't route packets between interfaces...or I don't know
> how to do it.
> Here's how I envisioned it:
> T1 Cable Modem
> | z.z.z.z/28 |
> | x.x.x.x/29 |
> | y.y.y.y/29 |
> -------------------- |
> | cisco 2621 | |
> --------------------- |
> e0| e1 |_________________|
> | switches |
> the cable modem is locked down to the point that I can't add routes to
> it...if I could I wouldn't be here right now...
> Is there a device to bridge the networks since apparently the 2621
> can't do it...or can the 2621 do it and I'm simply retarded. Can I
> put a linux box in there somewhere and use it to route between the two
> networks? I have no experience with xBSD so suggesting that won't go
> far but if it's the only answer I'll put it on my list of stuff to
> Any help or suggestions would be greatly appreciated.
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