ip forwarding

[Guest]

This is what I have.

Laptop - IP
172.16.5.6
255.255.255.0
Gateway = 172.16.5.1

Dell PowerEdge 2300 with 2 NIC’s and IP forwarding is enabled in the registry.
NIC 1 – IP
172.16.5.1
255.255.255.0
Gateway = None

NIC 2 – IP
192.167.1.75
255.255.255.0
Gateway = 192.167.1.1

Linksys router IP
192.167.1.1
255.255.255.0

Why can I not get out to the internet from the laptop? Do I need an
additional static route?

Thanks all,

 

[Ed Horley]

Your Linksys needs to know where to route 172.16.5.0/24 to, which in your
case is to 192.167.1.75. I am assuming the Linksys is doing NAT and
pointing upstream to a public IP address as a default gateway. You will
also need to make sure that the Linksys is doing NAT for the 172.16.5.0/24
block or it will die at the Linksys and never make it past that interface.
This is assuming you are not running a routing protocol like RIPv2 on the
Dell and Linksys (most likely not). So, add the static route to the Linksys
and make sure it will NAT (or PAT) the 172.16.5.0/24 address block and you
should be good to go.

Regards,
Ed Horley
Microsoft MVP Server-Networking

 

[Herb Martin]

This is what I have.

Laptop - IP
172.16.5.6
255.255.255.0
Gateway = 172.16.5.1

Dell PowerEdge 2300 with 2 NIC's and IP forwarding is enabled in the registry.
NIC 1 - IP
172.16.5.1
255.255.255.0
Gateway = None
NIC 2 - IP
192.167.1.75
255.255.255.0
Gateway = 192.167.1.1

Linksys router IP
192.167.1.1
255.255.255.0

Why can I not get out to the internet from the laptop?

It is actually due to the Linksy not "knowing"
about the additional net (172.16.x.y).

Do I need an additional static route?

Yes, on the linksys.

The equivalent of:
route add 172.16.0.0 mask 255.255.255.0 192.167.1.75

The Dell router can find the Internet because it
use the default gateway (route) to the Linksys
but the Linksys default gateway is (certainly) set
to the ISP so you must add a manual route to find
the network not directly connected but reachable
through a DIFFERENT router (not the ISP, but
through the Dell.

Rule: When you have a router between other
routers, the interior router(s) must have static
routes (unless you use dynamic routing for the
same purpose.)

I call it the "3-router rule". The "middle" router
needs the extra route.

What isn't obvious, is that with TWO INTERNAL
routers you really have 3 due to the ISP:

ISP---MiddleRouter(s)---EdgeRouter

(All of) the MiddlerRouter(s) need help.

 

[Guest]

I've added the static route into the Linksys router but still no luck. Could
you review this with me? Here's my email address (e-mail address removed) - and yes
thats my website www.gt350.net

 

[Herb Martin]

I've added the static route into the Linksys router but still no luck. Could
you review this with me? Here's my email address (e-mail address removed) - and yes
thats my website www.gt350.net

When ping fails (other than being blocked by
known firewalls) one usually tries "tracert"
to see where the traffic stops.

If you have added the route correctly then it
should be working.

Perhaps you added the route incorrectly or
(somehow) didn't activate it?

From the linksys you add a route to the NEAR
side of the Dell for the network "behind" the
Dell.

[/QUOTE]

 

[Guest]

From the laptop i typed at a command prompt tracert 4.2.2.2 it finds
172.16.5.1 (one of the NIC's in the Dell PowerEdge) then 192.167.1.1 (Linksys
router) then ends. So it's ending right at the router like you said.

In the Linksys router i added 3 routes all three routes are in the list.

route add 172.16.0.0 mask 255.255.255.0 192.167.1.75
route add 172.16.5.0 mask 255.255.255.0 192.167.1.1
route add 172.16.5.0 mask 255.255.255.0 192.167.1.75

I'm not sure what i'm doing so i added all 3 but they dont work

Ray

 

[Phillip Windell]

route add 172.16.0.0 mask 255.255.255.0 192.167.1.75
route add 172.16.5.0 mask 255.255.255.0 192.167.1.1
route add 172.16.5.0 mask 255.255.255.0 192.167.1.75

The third one is the correct one.

No one has mentioned this yet, but why are you running a Public Routable
Address block on the internal side of your network. Do you you actually own
that address block or did someone just arbitrarily pick it? 192.167.*.* is
not a Private block,..192.168.*.* is.

If the "Linksys router" is really a NAT Device (Internet Sharing Device)
then you should be running RFC Private address ranges behind it. However if
it is not a NAT Device then your Dell PowerEdge Server needs to run NAT
using RRAS.

There are too many possible things to be wrong and you have given enough
details to sort it out.

 

[Herb Martin]

From the laptop i typed at a command prompt tracert 4.2.2.2 it finds
172.16.5.1 (one of the NIC's in the Dell PowerEdge) then 192.167.1.1 (Linksys
router) then ends. So it's ending right at the router like you said.

In the Linksys router i added 3 routes all three routes are in the list.

route add 172.16.0.0 mask 255.255.255.0 192.167.1.75

This is the one that is irrelevant since
you don't have any machines on this net.
(172.16.0.x /24 -- you don't have any.)

route add 172.16.5.0 mask 255.255.255.0 192.167.1.1

This one is COUNTERPRODUCTIVE and
might screw it up if it gets precedence over
the others.

route add 172.16.5.0 mask 255.255.255.0 192.167.1.75

This is the ONE you need.

I'm not sure what i'm doing so i added all 3 but they dont work

 

[Herb Martin]

The third one is the correct one.
Correct.

No one has mentioned this yet, but why are you running a Public Routable
Address block on the internal side of your network. Do you you actually own
that address block or did someone just arbitrarily pick it? 192.167.*.* is
not a Private block,..192.168.*.* is.

If the "Linksys router" is really a NAT Device (Internet Sharing Device)
then you should be running RFC Private address ranges behind it. However if
it is not a NAT Device then your Dell PowerEdge Server needs to run NAT
using RRAS.

There are too many possible things to be wrong and you have given enough
details to sort it out.

The 'obvious' addresses to use there would
but 192.168.1.x or 172.16.1.0 but there are
thousands of other choices.