RE: Simple route/gateway forwarding

OK... is this a correct diagram?


  +-----------+          +------------+
  | 2811 RTR  |-PAT----->|  CPE-RTR A |
  +-----------+          +------------+
        | 192.168.7.1/21
        |
      /---\              +-----------+ 
     | LAN |-------------| CPE-RTR B |--PAT-->
      \---/              +-----------+
        |           192.168.7.10/21
        |
        | 192.168.7.x/21
    +--------+
    | CLIENT | 
    +--------+


- Brian


> -----Original Message-----
> From: [email protected] [mailto:list-bounces@inet-
> access.net] On Behalf Of James Smallacombe
> Sent: Monday, April 05, 2010 2:00 PM
> To: [email protected]
> Subject: RE: Simple route/gateway forwarding
> 
> On Mon, 5 Apr 2010, Brian Johnson wrote:
> 
> > What you are trying to do is definitely possible. How you are
stating
> > this makes my head hurt. :)
> 
> Sorry...I can see how it looks super-complex, but in reality, it's not
> too
> bad.
> 
> > You have a LAN using the 192.168.7.0/24 network. This network has
two
> 
> Actually, it's using 192.168.0.0/21.  Nothing in there is actually
> subnetted out, although, for example, 192.168.7.x is set aside for
> network
> equipment and 192.168.3.x is set aside for workstations, etc.
> 
> > externally facing routers and one internally facing router. The
> > internally facing router uses NAP (do you mean PAT, overloaded NAT?)
> and
> 
> Yes, like most NAT implementations like this, it is overloaded, not
> 1-to-1.
> 
> > uses the 192.168.0.0/21 network internally.
> >
> >        +------------+     +------------+
> >        | Provider A |     | Provider B |
> >        +------------+     +------------+
> >              |                  |
> >        +-----------+      +-----------+
> >        | CPE-RTR A |      | CPE-RTR B |
> >        +-----------+      +-----------+
> >  192.168.7.1/24  \          / 192.168.7.10/24
> >                   \        /
> 
> In the case of provider A, there is no customer access to their CPE
> router
> and it is not doing NAT.  NAT is being performed by the customer's
> 2811.
> RFC 1918 to the internal Ether and provider A's "real" /26 on the
> external
> Ether.  Provider B's Netgear is on the same LAN as the 2811's internal
> Ether and performing NAT to B's upstream network.  We DO have access
to
> this B's Netgear.  I gave it 192.168.7.10/21 while the 2811 bas
> 192.168.7.1/21.
> 
> >                 +------------+
> >                 | LAN SWITCH |
> >                 +------------+
> >                       |
> >                       | 192.168.7.2/24
> >                  +----------+               / ip route 0.0.0.0
> 0.0.0.0
> > 192.168.7.1
> 
> This is a little off.  192.168.7.1/21 is on the 2811's internal Etherm
> while a real IP is on the external interface.  The Cisco has
> 
> ip route 0.0.0.0 0.0.0.0 real.ip.of.A's.CPE.router
> 
> >                  | 2811 RTR | NAT/PAT   <--<  ip route 192.168.3.240
> > 255.255.255.255 192.168.7.10
> >                  +----------+               \
> 
> That looks correct, above.
> 
> >                       | 192.168.0.1/21
> 
> You mean the 192.168.0.0/21 network above, right?
> 
> > If this diagram is correct, and the CPE routers are configured
> > correctly, then packets bound for 192.168.3.240 WILL be forwarded to
> > 192.168.7.10. What that router does with it is another question all
> > together.
> >
> > Do you have access to the CPE routers? Are you using a routing
> protocol
> > or just static routes? You are dealing with all private IP addresses
> in
> > your example. Are they really all private IP addresses or are there
> some
> > public addresses in here?
> 
> Just static routes.  Want to avoid RIP and the Netgear doesn't do
OSPF.
> 
> > - Brian
> >
> >> -----Original Message-----
> >> From: [email protected] [mailto:list-bounces@inet-
> >> access.net] On Behalf Of James Smallacombe
> >> Sent: Monday, April 05, 2010 9:33 AM
> >> To: Inet-Access Mailing List
> >> Subject: Simple route/gateway forwarding
> >>
> >>
> >> This is really basic, but since I've never tried it before (and
it's
> >> not
> >> working), I want to see if it's possible, one way or another:
> >>
> >> customer has a network hooked up to provider A using provider's CPE
> >> router.  They also have a 2811 doing NAT, which is the default
> gateway
> >> for
> >> the NAT'd network 192.168.0.0/21.  The 2811 then has a default
route
> > to
> >> the CPE router and a typical "internal" Ethernet on 192.168.7.1 and
> an
> >> "external" Ethernet on Provider A's static IPs.
> >>
> >> To this, they add a second connection, a business broadband
> connection
> >> using a typical broadband router (NetGear, I believe) to provider
B.
> >> They know their provider A static IPs, won't route through provider
> > B's
> >> network, but certainly the NATed 192.168. network will.  I stick
the
> >> Netgear on the same Ether as the 2811's internal interface and give
> it
> >> 192.168.7.10.  All workstations use a default gateway of
> 192.168.7.1.
> >> The
> >> idea is to be able to switch them over to 192.168.7.10 without
> having
> >> to
> >> change their settings, by just re-routing some networks on the
Cisco
> > to
> >> provider B.  I tried this as a test:
> >>
> >> ip route 192.168.3.240 255.255.255.255 192.168.7.10
> >>
> >> Similar to a ppp /32 route.  However, all traffic from
192.168.3.240
> >> still
> >> goes out the default route to provider A via the default route.  Is
> >> there
> >> a way to make this work without subnetting 192.168.3.0 and putting
> >> aliases
> >> of it on one or both routers?
> >>
> >> James Smallacombe		      PlantageNet, Inc. CEO and Janitor
> >> [email protected]
> > http://3.am
> >>
> >
>
=======================================================================
> >> ==
> >> --
> >> Eat sushi frequently. - Avi
> >> [email protected] is the human contact address.
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> >> See below URL for subscribe/unsubscribe and list options:
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> >
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> > --
> > Eat sushi frequently. - Avi
> > [email protected] is the human contact address.
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> >
> 
> James Smallacombe		      PlantageNet, Inc. CEO and Janitor
> [email protected]
http://3.am
>
=======================================================================
> ==
> --
> Eat sushi frequently. - Avi
> [email protected] is the human contact address.
> [email protected] is the list posting address.
> See below URL for subscribe/unsubscribe and list options:
> http://inet-access.net/mailman/listinfo/list
-- 
Eat sushi frequently. - Avi
[email protected] is the human contact address.
[email protected] is the list posting address.
See below URL for subscribe/unsubscribe and list options:
http://inet-access.net/mailman/listinfo/list