"Downlinked" Router abd connectivity

Hi:

I am a relative novice at networking. I have added a Vonage phone to my
four PC Home Network (three running Windows XP Pro and one Linux Box),
plus changed my four port wired router to a four port plus 802.11g
wireless. Everything is generally cool. I have the four PC's connected
as follows...

| Port 1 -- PCA
| Port 2 -- PCB |Port 1 -- PCD
Modem --> 4-Prt Router | Port 3 --> Phone Router|Port 3 -- Open
| Port 4 -- PCC |Port 3 -- Open

The original hookup had just the four PC's on the one router and
everybody peacefully shared resources one with another. Now, PCA, PCB,
and PCC all still connect just fine. But PCD can "see" the other PC's
"upline" but the other three cannot see PCD. But PCD can link to the
Internet just fine.

PCA thru C have assigned IP's of 192.168.1.n. PCD is assigned 192.168.15.n

Is this just the way things are, or have I missed something basic? I
have all my firewall, port forwarding, etc. setup in the 4-Prt Router
but the Phone Router (A Linksys RT31P2) is connected upline as
192.168.1.51 and assigns downstream as 192.168.15.n.

Do I need to make the Local IP Address of the Phone Router a
192.168.1.??? number and make that the gateway in PCD?

To put it another way, I'd really like PCD and anything I plug into the
Phone Router to look just like more ports on the 4-Prt Router.

Please excuse my poor nomenclature. I am just learning networking.

Thanks for any advice.

Jess

On Sat, 22 Jan 2005 09:13:03 -0500, Jess Jackson <(E-Mail Removed)> wrote:
> Hi:
>
> I am a relative novice at networking. I have added a Vonage phone to my
> four PC Home Network (three running Windows XP Pro and one Linux Box),
> plus changed my four port wired router to a four port plus 802.11g
> wireless. Everything is generally cool. I have the four PC's connected
> as follows...
>
> | Port 1 -- PCA
> | Port 2 -- PCB |Port 1 -- PCD
> Modem --> 4-Prt Router | Port 3 --> Phone Router|Port 3 -- Open
> | Port 4 -- PCC |Port 3 -- Open
>
> The original hookup had just the four PC's on the one router and
> everybody peacefully shared resources one with another. Now, PCA, PCB,
> and PCC all still connect just fine. But PCD can "see" the other PC's
> "upline" but the other three cannot see PCD. But PCD can link to the
> Internet just fine.

What do you mean by "see"? If the phone router is doing NAT, you would
not be able to directly access an IP behind it from anything on your main
router. The only thing you might be able to do with phone router is
either forward specific ports to PCD or set it as DMZ, then access it from
main LAN as WAN IP of phone router.

If somehow you could disable NAT on the phone router to use it as a normal
router, PCs on the main router would need a route to PCD network using WAN
of phone router as gateway.

Without a wins server (which samba can do) Win file/printer sharing only
works on same LAN (broadcasting). But not sure how well or if that
would work to access PCD behind NAT (even if you made it DMZ or forwarded
ports). Although, if you forward port 22 to PCD (or as DMZ), you should
be able to access it with ssh/scp, through WAN IP of phone router (PuTTY
is a Win ssh/scp client).

> PCA thru C have assigned IP's of 192.168.1.n. PCD is assigned 192.168.15.n
>
> Is this just the way things are, or have I missed something basic? I
> have all my firewall, port forwarding, etc. setup in the 4-Prt Router
> but the Phone Router (A Linksys RT31P2) is connected upline as
> 192.168.1.51 and assigns downstream as 192.168.15.n.
>
> Do I need to make the Local IP Address of the Phone Router a
> 192.168.1.??? number and make that the gateway in PCD?

You cannot have the same network on LAN and WAN of router unless it is a
bridge, or if one side has different netmask or specific routing and does
proxy arp, without doing NAT.

I do something like that with my Linux router, where I have a
255.255.255.248 netmask portion of my main 255.255.255.0 LAN on a separate
nic for wireless, using proxy_arp so my wireless subnet appears to be part
of my LAN without requiring a specific gateway for it (Linux router
answers arp requests for either interface). But most consumer
gateway/routers are not that capable. And it still did not do broadcast
Win file sharing (which I did not want broadcast on wireless anyway).

Hi David:

You have well captured what I meant. The phone router does do NAT and by
"see" I mean access shared resources. I thought about trying the DMZ
idea. Of course, that only works for the one PC I set to be the DMZ
host. I will look into disabling NAT in the phone router. That should
have, I assume, no impact on the Vonage Phone accessing for phone service.

Thanks for the advice.

Jess

David Efflandt wrote:
> On Sat, 22 Jan 2005 09:13:03 -0500, Jess Jackson <(E-Mail Removed)> wrote:
>
>>Hi:
>>
>>I am a relative novice at networking. I have added a Vonage phone to my
>>four PC Home Network (three running Windows XP Pro and one Linux Box),
>>plus changed my four port wired router to a four port plus 802.11g
>>wireless. Everything is generally cool. I have the four PC's connected
>>as follows...
>>
>> | Port 1 -- PCA
>> | Port 2 -- PCB |Port 1 -- PCD
>>Modem --> 4-Prt Router | Port 3 --> Phone Router|Port 3 -- Open
>> | Port 4 -- PCC |Port 3 -- Open
>>
>>The original hookup had just the four PC's on the one router and
>>everybody peacefully shared resources one with another. Now, PCA, PCB,
>>and PCC all still connect just fine. But PCD can "see" the other PC's
>>"upline" but the other three cannot see PCD. But PCD can link to the
>>Internet just fine.
>
>
> What do you mean by "see"? If the phone router is doing NAT, you would
> not be able to directly access an IP behind it from anything on your main
> router. The only thing you might be able to do with phone router is
> either forward specific ports to PCD or set it as DMZ, then access it from
> main LAN as WAN IP of phone router.
>
> If somehow you could disable NAT on the phone router to use it as a normal
> router, PCs on the main router would need a route to PCD network using WAN
> of phone router as gateway.
>
> Without a wins server (which samba can do) Win file/printer sharing only
> works on same LAN (broadcasting). But not sure how well or if that
> would work to access PCD behind NAT (even if you made it DMZ or forwarded
> ports). Although, if you forward port 22 to PCD (or as DMZ), you should
> be able to access it with ssh/scp, through WAN IP of phone router (PuTTY
> is a Win ssh/scp client).
>
>
>>PCA thru C have assigned IP's of 192.168.1.n. PCD is assigned 192.168.15.n
>>
>>Is this just the way things are, or have I missed something basic? I
>>have all my firewall, port forwarding, etc. setup in the 4-Prt Router
>>but the Phone Router (A Linksys RT31P2) is connected upline as
>>192.168.1.51 and assigns downstream as 192.168.15.n.
>>
>>Do I need to make the Local IP Address of the Phone Router a
>>192.168.1.??? number and make that the gateway in PCD?
>
>
> You cannot have the same network on LAN and WAN of router unless it is a
> bridge, or if one side has different netmask or specific routing and does
> proxy arp, without doing NAT.
>
> I do something like that with my Linux router, where I have a
> 255.255.255.248 netmask portion of my main 255.255.255.0 LAN on a separate
> nic for wireless, using proxy_arp so my wireless subnet appears to be part
> of my LAN without requiring a specific gateway for it (Linux router
> answers arp requests for either interface). But most consumer
> gateway/routers are not that capable. And it still did not do broadcast
> Win file sharing (which I did not want broadcast on wireless anyway).

Jess Jackson wrote:
> Hi David:
>
> You have well captured what I meant. The phone router does do NAT and
by
> "see" I mean access shared resources. I thought about trying the DMZ
> idea. Of course, that only works for the one PC I set to be the DMZ
> host. I will look into disabling NAT in the phone router. That should

> have, I assume, no impact on the Vonage Phone accessing for phone
service.
>
> Thanks for the advice.
>
> Jess
>
> David Efflandt wrote:
> > On Sat, 22 Jan 2005 09:13:03 -0500, Jess Jackson
<(E-Mail Removed)> wrote:
> >
> >>Hi:
> >>
> >>I am a relative novice at networking. I have added a Vonage phone
to my
> >>four PC Home Network (three running Windows XP Pro and one Linux
Box),
> >>plus changed my four port wired router to a four port plus 802.11g
> >>wireless. Everything is generally cool. I have the four PC's
connected
> >>as follows...
> >>
> >> | Port 1 -- PCA
> >> | Port 2 -- PCB |Port 1 -- PCD
> >>Modem --> 4-Prt Router | Port 3 --> Phone Router|Port 3 -- Open
> >> | Port 4 -- PCC |Port 3 -- Open
> >>
> >>The original hookup had just the four PC's on the one router and
> >>everybody peacefully shared resources one with another. Now, PCA,
PCB,
> >>and PCC all still connect just fine. But PCD can "see" the other
PC's
> >>"upline" but the other three cannot see PCD. But PCD can link to
the
> >>Internet just fine.
> >
> >
> > What do you mean by "see"? If the phone router is doing NAT, you
would
> > not be able to directly access an IP behind it from anything on
your main
> > router. The only thing you might be able to do with phone router
is
> > either forward specific ports to PCD or set it as DMZ, then access
it from
> > main LAN as WAN IP of phone router.
> >
> > If somehow you could disable NAT on the phone router to use it as a
normal
> > router, PCs on the main router would need a route to PCD network
using WAN
> > of phone router as gateway.
> >
> > Without a wins server (which samba can do) Win file/printer sharing
only
> > works on same LAN (broadcasting). But not sure how well or if that
> > would work to access PCD behind NAT (even if you made it DMZ or
forwarded
> > ports). Although, if you forward port 22 to PCD (or as DMZ), you
should
> > be able to access it with ssh/scp, through WAN IP of phone router
(PuTTY
> > is a Win ssh/scp client).
> >
> >
> >>PCA thru C have assigned IP's of 192.168.1.n. PCD is assigned
192.168.15.n
> >>
> >>Is this just the way things are, or have I missed something basic?
I
> >>have all my firewall, port forwarding, etc. setup in the 4-Prt
Router
> >>but the Phone Router (A Linksys RT31P2) is connected upline as
> >>192.168.1.51 and assigns downstream as 192.168.15.n.
> >>
> >>Do I need to make the Local IP Address of the Phone Router a
> >>192.168.1.??? number and make that the gateway in PCD?
> >
> >
> > You cannot have the same network on LAN and WAN of router unless it
is a
> > bridge, or if one side has different netmask or specific routing
and does
> > proxy arp, without doing NAT.
> >
> > I do something like that with my Linux router, where I have a
> > 255.255.255.248 netmask portion of my main 255.255.255.0 LAN on a
separate
> > nic for wireless, using proxy_arp so my wireless subnet appears to
be part
> > of my LAN without requiring a specific gateway for it (Linux router

> > answers arp requests for either interface). But most consumer
> > gateway/routers are not that capable. And it still did not do
broadcast
> > Win file sharing (which I did not want broadcast on wireless
anyway).

As near as I can tell from looking at the user's guide, the new
"router" simply routes from the uplink side to downstream (switched?)
ports for your PCs and phones.

Result:
Downstream of the "new" router is on a different lan 192.168.15.0/24
while the uplink side is on 192.168.1.0/24 (192.168.1.51). The
downstream hosts are assigned IPs in the 192.168.15.2 - 192.168.15.253
(max) range. See page 20 of the guide.

You can change it so the new router dishes up IPs in the "correct"
192.168.1.0/24 range so that your "new" connections are part of the
same lan as the original connections.

However:
I would probably place the _new_ router immediately behind the dsl
modem and connect the "old" router/switch to a port on the new one (the
"old" PCs may have to be assigned static addresses -- not sure if the
"old router" is in fact, a router or a switch or has configurable DHCP
range or if "new" router will assign them proper IPs through your "old"
switch/router).

Why:
The VoIP connections will need as much bandwidth as possible for
reliable phone use and "competing" with PCs internet gaming or
downloading files etc. will adversely affect the bandwidth available to
VoIP. The new router has the ability to give your VoIP connections a
greater share of the total bandwidth, thus maintaining QoS (Quality of
Service). See page 35-37. You may have to poke around the Vonage site
to see what they recommend for VoIP.

It's hard to tell from the guide if the QoS configuration options will
be of much use or not. May depend on how the PCs use the network. May
require the original PCs to all work from a single port on the "new"
router. Just thought I would point out that you ought to look into it


hth,
prg
email above disabled