Puzzled - 2 routers

hudson · 27 Jul 2009 at 22:45

Guys I dont think what I am attemoting to achieve is possible but i'll have a go at explaining.

I have a sky netgaer router with adsl in my back bedroom. That runs a laptop in the room and also connects tot he LAN over power socket connectors you know the through your house electrical loom networkign stuff.

So i have the other end of that ip over electricity device in my front bedroom.

Originally connected to my pc. I now want to conenct my ps3 to the network, can i put a netgear routeron the end of the power lan and if so what settings should i use.

I made a basic drawing

Rroff · 27 Jul 2009 at 22:51

Nominally you can only have 1 router (with incoming internet connection) on a network - ok you _can_ have multiple gateways devices, etc. but thats another story...

What you probably need is a hub or switch (preferably a switch).

EDIT: Ah you do mention a switch in your diagram.

hudson · 27 Jul 2009 at 22:59

yeah i figured a managed switch would suit me best, I'll see what I can find knocking around.

Thanks matey.

Caged · 27 Jul 2009 at 23:03

Who said anything about a managed switch?

You can turn your second router into a "switch" quite easily by connecting it to a PC (not part of your other network) via the LAN port, going into the config page for it and disabling the DHCP server while also setting the IP address to one not in a range you use on your network currently. Then you just need to connect everything to the LAN side of the router and it might as well be a switch. Just don't go resetting it.

Rroff · 28 Jul 2009 at 00:31

Caged said:
Who said anything about a managed switch?

You can turn your second router into a "switch" quite easily by connecting it to a PC (not part of your other network) via the LAN port, going into the config page for it and disabling the DHCP server while also setting the IP address to one not in a range you use on your network currently. Then you just need to connect everything to the LAN side of the router and it might as well be a switch. Just don't go resetting it.

This is true on many multi port routers you can "dumb" them down to act like a semi-managed switch.

Sin_Chase · 28 Jul 2009 at 01:26

You do not need a managed anything.

A dumb hub would work, but you want a switch. You can, as stated, use a router as a switch. Just turn off NAT, Firewalls and any other "security" features it might sport.

hudson · 28 Jul 2009 at 10:43

I'll have a go with this tonight, i couldnt get my head round segmenting my network because of having two routers..... but dumbing down would be ideal.

Skidilliplop · 28 Jul 2009 at 11:30

The key question that I feel has been missed here is do you already own the second netgear router? IF so, dumb it down as described and use that, why spend money when you don't have to. IF you don't already own it and are looking at spending £30 or so on it then you'd be better off buying a small netgear switch. They do a 5 port gigabit unmanaged switch for about £25 that will suit your needs perfectly.

Dumbing down = turning off DHCP or making sure it's scope is on the same subnet but not overlapping with the other scope (there are advantages to having split scopes beyond the content of this thread) and disable any wireless you're not using. As for NAT routing etc these can be left on as there's no reason why any frames will be addressed to the router's interface, and thus it won't process them. The default gateway will be the Sky router that's where any non-local frames will be addressed to.

As a rule the les you tweak the router from it's default setup the less likely it is to do unexpected things.

hudson · 28 Jul 2009 at 13:18

Ok, I understand that. What i was doing wrong then is trying to assign the router onto a different subnet and then trying to nat traffic accross to the other router.

What has puzzled me isnt the seocnd router going to need an ipaddress, or if its dumb then will it just act like a relay.

I already own the second router hence the question - but as you say for 30 quid i can pick up a dumb switch/hub and go about it that way.

I'll post my results tonight and let you know how things go

hudson · 28 Jul 2009 at 22:18

Ok my new puzzle.

If i turn off dhcp on the second router then how do get my machiens to pick up dhcp?

So far my router (dumb) picks up an address form the other router but then how do i know what ip to assign my devices (assuming of course i have to) and is my gateway the new router or the only one that is farming out dhcp....

i'm lost in routing now....

Skidilliplop · 29 Jul 2009 at 09:30

Is this a cable router or an ADSL router? You only want to be using the LAN Ports. The router itself only comes into play if dtraffic is passing from WAN to LAN or vice versa. If traffic enters on a LAN port destined for a machine on the LAN it will be passed out of the relevant LAN port based on the switches CAM Table.
DHCP requests will be broadcast out all ports on both routers and responded to by which ever router is running DHCP.

It's difficult to explain WHY without going into a lesson on logical and physical addressing and broadcast domains. But provided DHCP is off you can plug one router into LAN port 1 and your other devices into the remaining LAN ports and it will extend the original LAN across those ports.

Sin_Chase · 29 Jul 2009 at 12:05

Only 1 of your routers should have DHCP on, not both.

Give your "dumb" router a static address outside of your DHCP range and your main router the role of serving DHCP.

If you want to give your devices a static address from DHCP you can use MAC address reservations - Providing your router supports this (It should).

Think your of your Dumb router as NOTHING but a switch, it has no roles other than connecting your devices. Your original router with your net connection does all of the fancy stuff.

cokecan · 29 Jul 2009 at 12:16

I run this kind of setup at home

I have a linksys as my main router that has VM internet conencted to it, then a cable running to another room that plugs into one of the 4 ports of the 2nd router (not the wan port!).

The first router is configured as 192.168.0.1 with a 255.255.255.0 subnet, DHCP is enabled as is firewall etc. The second router is configured as 192.168.0.2 with a subnet of 255.255.255.0, it also has DHCP, firewall and everything else disabled so all it does is act as a basic switch.

Any pc connected to the second router will get an IP addy from the dhcp server on the first router. The second router just passes the connection on

Sin_Chase · 29 Jul 2009 at 12:19

This:

hudson · 29 Jul 2009 at 14:18

Yeah i figured it out in a fit of fury this morning while driving to work.... I've been plugging intot he sodding interface port not the lan port.

I'll try again this evening.