Routing 10.0.0.0 through Linksys router to my Cisco DSLmodem?

I've got this physical network setup:

ISP <--> Cisco 678 DSL modem <--> Linksys BEFSR41 router <--> PC eth1

My Linksys connection to the modem is 65.75.X.X.
The Linksys connection to the PC is 192.168.1.1.
The PC connection to the Linksys is 192.168.1.3.
The Cisco 678 has an administration interface at 10.0.0.1 that I
used to use from the PC via HTTP _before_ I installed the Linksys.
I can no longer connect to 10.0.0.1 on the Cisco from the PC
_after_ installing the Linksys. All other networking works fine
though.

I tried to route all 10.0.0.0 traffic through eth1 like so

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
10.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eth1
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth1

What might I have done wrong and/or what can I do to get access to
the Cisco from my PC again?

Thanks....


--
PLEASE post a SUMMARY of the answer(s) to your question(s)!
Unless otherwise noted, the statements herein reflect my personal
opinions and not those of any organization with which I may be affiliated.

Kevin wrote:
> I've got this physical network setup:
>
> ISP <--> Cisco 678 DSL modem <--> Linksys BEFSR41 router <--> PC eth1
>
> My Linksys connection to the modem is 65.75.X.X.
> The Linksys connection to the PC is 192.168.1.1.
> The PC connection to the Linksys is 192.168.1.3.
> The Cisco 678 has an administration interface at 10.0.0.1 that I
> used to use from the PC via HTTP _before_ I installed the Linksys.
> I can no longer connect to 10.0.0.1 on the Cisco from the PC
> _after_ installing the Linksys. All other networking works fine
> though.
>
> I tried to route all 10.0.0.0 traffic through eth1 like so
>
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use Iface
> 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
> 10.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eth1
> 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
> 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth1
>
> What might I have done wrong and/or what can I do to get access to
> the Cisco from my PC again?

You'll have to route the 10.0.0.0 network to the right destination on
the Linksys router, not the Linux box. You want the Linux box to use
the router at 192.168.1.1 as its gateway to 10.0.0.0, which is handled
by the default gateway at the bottom of the routing table anyway. What
you need to do is figure out how (if it's possible) to give that routing
command to the Linksys router.

On 02 Aug 2004 18:31:42 GMT, Kevin <(E-Mail Removed)> wrote:
> I've got this physical network setup:
>
> ISP <--> Cisco 678 DSL modem <--> Linksys BEFSR41 router <--> PC eth1
>
> My Linksys connection to the modem is 65.75.X.X.
> The Linksys connection to the PC is 192.168.1.1.
> The PC connection to the Linksys is 192.168.1.3.
> The Cisco 678 has an administration interface at 10.0.0.1 that I
> used to use from the PC via HTTP _before_ I installed the Linksys.
> I can no longer connect to 10.0.0.1 on the Cisco from the PC
> _after_ installing the Linksys. All other networking works fine
> though.
>
> I tried to route all 10.0.0.0 traffic through eth1 like so
>
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use Iface
> 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
> 10.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eth1
> 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
> 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth1

The 10.0.0.0/8 local route on your PC would not help at all, because the
10... IP you are trying to reach is not local (will not answer arp
requests from there).

> What might I have done wrong and/or what can I do to get access to
> the Cisco from my PC again?

If your router is using PPPoE, or has no way to set static routes on its
ethernet WAN, it may be impossible to access the Cisco from behind the
Linksys.

If the Linksys is doing PPPoE, it is not using ethernet tcp/ip, therefore
would be unable to communicate with your modem config.

Even if the Linksys to Cisco connection is ethernet tcp/ip (DHCP or static
WAN), it probably has no method to set alternate static routes on that
interface, therefore, modem config is unreachable.

The only way you could possibly connect from PC to Cisco config would be
if the Linksys to Cisco connection was using ethernet tcp/ip AND you could
set a static route for that IP on the Linksys WAN.

--
David Efflandt - All spam ignored http://www.de-srv.com/

On 02 Aug 2004 18:31:42 GMT, Kevin wrote:
> I've got this physical network setup:
>
> ISP <--> Cisco 678 DSL modem <--> Linksys BEFSR41 router <--> PC eth1
>
> My Linksys connection to the modem is 65.75.X.X.
> The Linksys connection to the PC is 192.168.1.1.
> The PC connection to the Linksys is 192.168.1.3.
> The Cisco 678 has an administration interface at 10.0.0.1 that I
> used to use from the PC via HTTP _before_ I installed the Linksys.
> I can no longer connect to 10.0.0.1 on the Cisco from the PC
> _after_ installing the Linksys. All other networking works fine
> though.
>
> I tried to route all 10.0.0.0 traffic through eth1 like so
>
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use Iface
> 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
> 10.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eth1
> 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
> 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth1
>
> What might I have done wrong and/or what can I do to get access to
> the Cisco from my PC again?

As was noted having the 10.0.0.0 in your Linux box is not enough and
it should actually point to your Linksys (192.168.1.1, not 0.0.0.0).
Unfortunately I have no idea how to configure your Linksys to point to
your Cisco since the Linksys is on the 65.75.x.x network. It maybe
that the default route will cover it but I doubt it and I don't think
there is a way to just say 'out this interface' as you have done with
the Linux box.

--
Linux Home Automation Neil Cherry (E-Mail Removed)
http://home.comcast.net/~ncherry/ (Text only)
http://linuxha.sourceforge.net/ (SourceForge)
http://hcs.sourceforge.net/ (HCS II)

John-Paul Stewart <(E-Mail Removed)> wrote:
> Kevin wrote:
> > Kernel IP routing table
> > Destination Gateway Genmask Flags Metric Ref Use Iface
> > 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
> > 10.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eth1
> > 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
> > 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth1
>
> You'll have to route the 10.0.0.0 network to the right destination on
> the Linksys router, not the Linux box. You want the Linux box to use
> the router at 192.168.1.1 as its gateway to 10.0.0.0, which is handled
> by the default gateway at the bottom of the routing table anyway. What
> you need to do is figure out how (if it's possible) to give that routing
> command to the Linksys router.

Doesn't anything headed at the Linksys get routed out of it? For
instance, I don't have to tell the Linksys anything at all about
how to get to 100.30.20.2, or any other IP address or network.
Why would 10.0.0.0 be any different?

Thanks...

--
PLEASE post a SUMMARY of the answer(s) to your question(s)!
Unless otherwise noted, the statements herein reflect my personal
opinions and not those of any organization with which I may be affiliated.

David Efflandt <(E-Mail Removed)> wrote:
> If your router is using PPPoE, or has no way to set static routes on its
> ethernet WAN, it may be impossible to access the Cisco from behind the
> Linksys.
>
> If the Linksys is doing PPPoE, it is not using ethernet tcp/ip, therefore
> would be unable to communicate with your modem config.

No PPPoE here.

> Even if the Linksys to Cisco connection is ethernet tcp/ip (DHCP or static
> WAN), it probably has no method to set alternate static routes on that
> interface, therefore, modem config is unreachable.

Connection is TCP/IP with static IP address.

> The only way you could possibly connect from PC to Cisco config would be
> if the Linksys to Cisco connection was using ethernet tcp/ip AND you could
> set a static route for that IP on the Linksys WAN.

This is hard for me to understand, not being a heavy networking
type. All TCP/IP traffic out of the Linksys goes through the
Cisco, and there is only one connection between the Cisco and the
Linksys. Why would the Linksys be confused on where to route
10.0.0.X packets when it passes packets bound for all other
destinations? I'm not trying to be obstinate; I'm just ignorant
about this and want to understand better.

Thanks....

--
PLEASE post a SUMMARY of the answer(s) to your question(s)!
Unless otherwise noted, the statements herein reflect my personal
opinions and not those of any organization with which I may be affiliated.

Neil Cherry <(E-Mail Removed)> wrote:
> As was noted having the 10.0.0.0 in your Linux box is not enough and
> it should actually point to your Linksys (192.168.1.1, not 0.0.0.0).

It's not enought to call 192.168.1.1 the default gateway (i.e.
0.0.0.0) and route 10.0.0.0 to the default gateway? Wouldn't
that map like this:

10.0.0.0 --> 0.0.0.0 --> 192.168.1.1

???

Thanks again....

> Unfortunately I have no idea how to configure your Linksys to point to
> your Cisco since the Linksys is on the 65.75.x.x network. It maybe
> that the default route will cover it but I doubt it and I don't think
> there is a way to just say 'out this interface' as you have done with
> the Linux box.


--
PLEASE post a SUMMARY of the answer(s) to your question(s)!
Unless otherwise noted, the statements herein reflect my personal
opinions and not those of any organization with which I may be affiliated.

Kevin wrote:

> I've got this physical network setup:
>
> ISP <--> Cisco 678 DSL modem <--> Linksys BEFSR41 router <--> PC eth1
>
> My Linksys connection to the modem is 65.75.X.X.
> The Linksys connection to the PC is 192.168.1.1.
> The PC connection to the Linksys is 192.168.1.3.
> The Cisco 678 has an administration interface at 10.0.0.1 that I
> used to use from the PC via HTTP _before_ I installed the Linksys.
> I can no longer connect to 10.0.0.1 on the Cisco from the PC
> _after_ installing the Linksys. All other networking works fine
> though.
>
> I tried to route all 10.0.0.0 traffic through eth1 like so
>
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use
> Iface
> 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0
> eth1
> 10.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0
> eth1
> 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
> 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0
> eth1
>
> What might I have done wrong and/or what can I do to get access to
> the Cisco from my PC again?
>
> Thanks....
>
>
This is quite intresting. You have a gateway on eth1 that is up running,
this gateway is for all traffic out. Have you tried to remove the post
10.0.0.0 0.0.0.0 255.0.0.0 ?
As I see it, (I can be wrong haven't done any routing for a few years) this
post is not necessary for you to get out through the gateway to whatever
network you like. Correct me if I'm wrong.

Micke

Kevin wrote:
> John-Paul Stewart <(E-Mail Removed)> wrote:
>
>>Kevin wrote:
>>
>>>Kernel IP routing table
>>>Destination Gateway Genmask Flags Metric Ref Use Iface
>>>192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
>>>10.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eth1
>>>127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
>>>0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth1
>>
>>You'll have to route the 10.0.0.0 network to the right destination on
>>the Linksys router, not the Linux box. You want the Linux box to use
>>the router at 192.168.1.1 as its gateway to 10.0.0.0, which is handled
>>by the default gateway at the bottom of the routing table anyway. What
>>you need to do is figure out how (if it's possible) to give that routing
>>command to the Linksys router.
>
>
> Doesn't anything headed at the Linksys get routed out of it? For
> instance, I don't have to tell the Linksys anything at all about
> how to get to 100.30.20.2, or any other IP address or network.
> Why would 10.0.0.0 be any different?

10.x.x.x (and 192.168.x.x) are addresses reserved for private use. They
are not supposed to be routed over the Internet. Routing in such a way
is considered a bug according to some RFC, IIRC. I would think (I would
*hope*) that the Linksys router is configured *not* to send packets to
10.x.x.x or 192.168.x.x outbound over its WAN port. Thus you'd need to
override that behaviour, if Linksys offers such an override.

On 03 Aug 2004 21:11:48 GMT, Kevin wrote:
> Neil Cherry <(E-Mail Removed)> wrote:
>> As was noted having the 10.0.0.0 in your Linux box is not enough and
>> it should actually point to your Linksys (192.168.1.1, not 0.0.0.0).
>
> It's not enought to call 192.168.1.1 the default gateway (i.e.
> 0.0.0.0) and route 10.0.0.0 to the default gateway? Wouldn't
> that map like this:
>
> 10.0.0.0 --> 0.0.0.0 --> 192.168.1.1

I only have a minute to answer this right now, so let me give you the
short answer: no. Because the 10.x.x.x get sen to the 192.168.1.1. It
doesn't havea route to the 10.0.0.0 network so it forwards it to it's
default your ISP router. Now this is where it get complicated. It may
be that the ISP router is not set up to forward the 10.x.x.x back to
your Cisco because it came in on the same interface (that't a really
bad explaination). I'll try to think this through some more and see if
I can explain it better or come up with something better (like a
fix).

--
Linux Home Automation Neil Cherry (E-Mail Removed)
http://home.comcast.net/~ncherry/ (Text only)
http://linuxha.sourceforge.net/ (SourceForge)
http://hcs.sourceforge.net/ (HCS II)