Re: Simple route/gateway forwarding
Henry Yen <[email protected]> Tue, 6 Apr 2010 15:15:37 -0400
| Newsgroups | gmane.org.operators.internet-access |
|---|---|
| Message-ID | <[email protected]> |
Why not just move the CPE-B router to the same segment as CPE-A, and then
let the 2811 do the "hard" work?
CPE-A CPE-B
| |
+--------------+
|
2811
|
--- i n t e r n a l ---
Now you don't need to switch default gateways for your internal network,
either. Or, is there something more complex you need to do?
On Mon, Apr 05, 2010 at 16:31:20PM -0400, James Smallacombe wrote:
>
> Spot on.
>
> On Mon, 5 Apr 2010, Brian Johnson wrote:
>
> > 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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> >>>> http://inet-access.net/mailman/listinfo/list
> >>>
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> >>> --
> >>> 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
> >>>
> >>
> >> 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
> >
>
> 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
--
Henry Yen Aegis Information Systems, Inc.
Senior Systems Programmer Hicksville, New York
--
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