Advice on setting up 2 routers

[Net_1100101]

Hello,

I've looking for ways to setup my network and needed some advice to make sure I'm on a good path and also how to complete some configurations.

I have Bell FTTN with Fibe TV (IPTV) using the HH2000 modem.

My goal is to connect 2 routers (Asus RT-68U running Merlin and Netgear R7000 running Vortex) to it but keeping only 1 of the routers in charge of the DHCP server:

HH2000_ _ _ LAN1 _ _ _ _ _ _ _ _ R7000
| | | |_ _ _ _ LAN2 _ _ _ _ _ _ _ _ AC68
| | |_ _ _ _ _ LAN3 _ _ _ _ _ _ _ _ Fibe TV Receiver Transmitter (router for the TV receivers)
| |_ _ _ _ _ _LAN4 _ _ _ _ _ _ _ _ N/C
|_ _ _ _ _ _ HPNA _ _ _ _ _ _ _ TV Receiver (can be moved to LAN4)

Bell HH2000 - connected with my real PPPoE credential (what I learnt so far is that I can't put it in bridge mode because I have FTTN with Fibe TV which is under a different VLAN). Current IP: 192.168.1.1/24

R700 - would be the main router. I set it up to connect to PPPoE directly as well. I setup a VPN server on it. Current IP: 192.168.2.1/24

AC68 - would be the secondary router. I set it up to connect to PPPoE directly as well (I hope Bell let me have 3 simultaneous connections). I setup a VPN client on it. Current IP: 192.168.3.1/24

My questions:
Is it possible to combine both routers and the modem under the same subnet and setup the main router (R7000) as the only DHCP server?
If not, can this be done between both routers only using the current configuration? (both connected to the modem).
Or, do I have to disable PPPoE in 1 router? I don't need 3 different external IPs but it'll be nice to have 2

Would another firmware (e.g DD-WRT) make it easier to configure them this way?

My main goal is to have a VPN server and client running simultaneously and all clients connected to both routers to be able to see/communicate with each others. It'll be nice to have 2 PPPoE IPs. I want to use the modem for the TV only (unless if there is a way to get it to work through the router, that'll be even better).
Putting all devices under the same subnet/DHCP is not very important if it can be done through IP route or DNS.

Thanks in advance

 

[sandman_1]

Hello,

I've looking for ways to setup my network and needed some advice to make sure I'm on a good path and also how to complete some configurations.

I have Bell FTTN with Fibe TV (IPTV) using the HH2000 modem.

My goal is to connect 2 routers (Asus RT-68U running Merlin and Netgear R7000 running Vortex) to it but keeping only 1 of the routers in charge of the DHCP server:

HH2000_ _ _ LAN1 _ _ _ _ _ _ _ _ R7000
| | | |_ _ _ _ LAN2 _ _ _ _ _ _ _ _ AC68
| | |_ _ _ _ _ LAN3 _ _ _ _ _ _ _ _ Fibe TV Receiver Transmitter (router for the TV receivers)
| |_ _ _ _ _ _LAN4 _ _ _ _ _ _ _ _ N/C
|_ _ _ _ _ _ HPNA _ _ _ _ _ _ _ TV Receiver (can be moved to LAN4)

Bell HH2000 - connected with my real PPPoE credential (what I learnt so far is that I can't put it in bridge mode because I have FTTN with Fibe TV which is under a different VLAN). Current IP: 192.168.1.1/24

R700 - would be the main router. I set it up to connect to PPPoE directly as well. I setup a VPN server on it. Current IP: 192.168.2.1/24

AC68 - would be the secondary router. I set it up to connect to PPPoE directly as well (I hope Bell let me have 3 simultaneous connections). I setup a VPN client on it. Current IP: 192.168.3.1/24

My questions:
Is it possible to combine both routers and the modem under the same subnet and setup the main router (R7000) as the only DHCP server?
If not, can this be done between both routers only using the current configuration? (both connected to the modem).
Or, do I have to disable PPPoE in 1 router? I don't need 3 different external IPs but it'll be nice to have 2

Would another firmware (e.g DD-WRT) make it easier to configure them this way?

My main goal is to have a VPN server and client running simultaneously and all clients connected to both routers to be able to see/communicate with each others. It'll be nice to have 2 PPPoE IPs. I want to use the modem for the TV only (unless if there is a way to get it to work through the router, that'll be even better).
Putting all devices under the same subnet/DHCP is not very important if it can be done through IP route or DNS.

Thanks in advance

Yes it is possible. However, since you can't bridge the HH2000, I would have it as the DHCP server and put the other 2 routers in "Access Point" mode, which will turn off DHCP and NAT on those routers.

 

[Mokers]

See if you can setup a DMZ on the HH2000. It is not the same as bridge mode, but it would allow you to use another device as a gateway a little easier.

 

[Net_1100101]

Yes it is possible. However, since you can't bridge the HH2000, I would have it as the DHCP server and put the other 2 routers in "Access Point" mode, which will turn off DHCP and NAT on those routers.

Thanks for the suggestion, that's actually how I set it up earlier but I thought it'll be better to let the routers deal with routing the traffic and let the modem deal with the DSL conversion only.

 

[Net_1100101]

See if you can setup a DMZ on the HH2000. It is not the same as bridge mode, but it would allow you to use another device as a gateway a little easier.

I was able to set it up this way before but the problem is that I needed another router to cover the deadspots as well as to have both VPN server and client operational simultaneously (which can't be done within a single router AFAIK).

It seems to me that it's impossible to have both routers under the same DHCP server, is there a way to setup a routing table for both routers to see each others as well as their clients?

 

[coxhaus]

Your ISP is only going to give you 1 IP address unless you pay for more so you need to live within those constraints.

If you have more than 1 IP then you can plug a switch into your modem and plug as many routers in as you have IP addresses.

 

[Net_1100101]

Your ISP is only going to give you 1 IP address unless you pay for more so you need to live within those constraints.

If you have more than 1 IP then you can plug a switch into your modem and plug as many routers in as you have IP addresses.

I was able to get 3 IPs so far (they might block 1 or 2 of them later on).
The modem has a router with 4 LAN ports. I connected 2 routers to the modem but the problem is that the devices connected to router 1 cannot communicate with those connected to router 2 (and vice versa).
This is why I'm wondering how to configure them in order for all devices connected to router 1 and 2 to communicate with each others

I can put them all under the same external IP but it'll be hard for me to connect router 2's WAN to router 1's LAN which would've made this setup much easier

 

[coxhaus]

Are you getting public IP addresses or private IP addresses? I don't think ISPs make mistakes like giving out to many public IP addresses.

I think what you are talking about above is double NAT which is not a good router setup but people do it.

 

[Net_1100101]

Are you getting public IP addresses or private IP addresses? I don't think ISPs make mistakes like giving out to many IP addresses.

They are all public. I read on another forum people were getting multiple IPs from Bell Canada that's I did it.
When I tried to do it few years ago, they blocked my 2nd one within few days. It looks like they relaxed the rules now

 

[coxhaus]

Then your best bet to run 2 routers is to use 2 public IP addresses so you don't run double NAT.

 

[Net_1100101]

Then your best bet to run 2 routers is to use 2 public IP addresses so you don't run double NAT.

Correct, that's how they are setup right now.
Do you know how to get the devices connected to both routers to see each others? (I can't ping from router 1 to 2)

 

[coxhaus]

The way I would do it is to add a CAT5e cable between the 2 routers on a separate VLAN so DHCP still works. No DHCP needed on the router connection VLAN just use a point to point mask with a static IP. Then add routing statements between routers to point to the networks on the other routers. I have no idea whether your router supports this or not. I actually would use a layer 3 switch between the routers.

You could also use a routing protocol between routers if you had support in your routers. Turn on a routing protocol on the link between routers so you are broadcasting routes across the link to each router.

You need to break the broadcast domains between routers or otherwise DHCP is not going to work on each router. I run DHCP on my layer 3 switch and not on my router so setup is a little different but basically the same.

 

[sandman_1]

Correct, that's how they are setup right now.
Do you know how to get the devices connected to both routers to see each others? (I can't ping from router 1 to 2)

It sounds like the ISP gateway is blocking it.

Simplest method is what I described earlier. It should allow all your devices to communicate with each other without much configuration.

Or you could put the routers on their own subnet and do static routes. Most consumer grade routers to my knowledge, do not do even simple routing protocols like RIPv2. You would have to do a static route on each router, 1 for the route to the next hop (gateway), and a return route on the opposing router, so as to communication back and forth on the different subnets. I would disable NAT on both routers and even the firewalls if you are using the HH2000 to do a firewall and NAT. More complicated but doable...

Sample layout in picture:

 

[Mokers]

I was able to set it up this way before but the problem is that I needed another router to cover the deadspots as well as to have both VPN server and client operational simultaneously (which can't be done within a single router AFAIK).

It seems to me that it's impossible to have both routers under the same DHCP server, is there a way to setup a routing table for both routers to see each others as well as their clients?

I am not sure why both of them need to be routers. You can place the second router in bridge mode (connect the upllink to a LAN port) and won't send out DHCP. another way you can do it is to disable wireless on the router and plug a few access points into the LAN instead.

 

[coxhaus]

It sounds like the ISP gateway is blocking it.

Simplest method is what I described earlier. It should allow all your devices to communicate with each other without much configuration.

Or you could put the routers on their own subnet and do static routes. Most consumer grade routers to my knowledge, do not do even simple routing protocols like RIPv2. You would have to do a static route on each router, 1 for the route to the next hop (gateway), and a return route on the opposing router, so as to communication back and forth on the different subnets. I would disable NAT on both routers and even the firewalls if you are using the HH2000 to do a firewall and NAT. More complicated but doable...

Sample layout in picture:

View attachment 12355

Setting a static IP on routers is not a problem. The problem is not having DHCP for all the clients. You can only run DHCP server in 1 broadcast domain. So connecting the 2 routers together makes one big broadcast domain. As stated above you need to break the broadcast domains to allow multiple DHCP servers.

Using a layer 3 switch with DHCP server fixes this problem so all you need is static IPs on the routers as the layer 3 switch does DHCP for all the clients.

 

[sandman_1]

Router's separate broadcast domains. If I send out a broadcast on network 192.168.2.0/24, it will not get past the Asus router. The setup I posted does in fact have multiple DHCP servers, 3 in fact. Although, you necessary don't need a DHCP server on the HH2000 and could just statically assign the IPs since there are only 3 devices in that network or just use a /29 subnet.

 

[coxhaus]

Router's separate broadcast domains. If I send out a broadcast on network 192.168.2.0/24, it will not get past the Asus router. The setup I posted does in fact have multiple DHCP servers, 3 in fact. Although, you necessary don't need a DHCP server on the HH2000 and could just statically assign the IPs since there are only 3 devices in that network or just use a /29 subnet.

DHCP is layer 2 not layer 3 so I think you are wrong about routers separate broadcast domains. If you plug 2 routers together on the LAN side they will both respond to DHCP requests randomly.

 

[sandman_1]

http://study-ccna.com/collision-broadcast-domain/

Broadcast domain
A broadcast domain is a domain in which a broadcast is forwarded. A broadcast domain contains all devices that can reach each other at the data link layer (OSI layer 2) by using broadcast. All ports on a hub or a switch are by default in the same broadcast domain. All ports on a router are in the different broadcast domains and routers don’t forward broadcasts from one broadcast domain to another.

DHCP is a layer 7 protocol.

You are describing a cascaded router setup. The routers in my diagram are not cascaded. They are connect to the HH2000 switch.

 

[coxhaus]

Your CCNA guide is saying what I said. Look at it close. OSI layer 2. This is where DHCP request are broadcast, at layer 2. Think about it the device does not have an IP address which is layer 3. It is requesting an IP using DHCP.

That bottom part is only related to Cisco IOS routers because they do not have switches built-in.
The routers on this site have switches built-in which negate the bold print. The small business Cisco routers like RV320 do have switches built-in so again that statement is not true. The other way to interpret the bold statement is you need to add DHCP relay or IP helper address (IOS routers) to pass DHCP requests from network to another network which does not apply in this thread.

Keep working on your CCNA. It is worth it in the end.

 

[sandman_1]

DHCP is not a layer 2 protocol. The device sending the DCHP request uses the IP 255.255.255.255 with a source of 0.0.0.0 to the subnet it is in.

http://searchnetworking.techtarget.com/definition/DHCP

How DHCP works
DHCP runs at the application layer of the Transmission Control Protocol/IP (TCP/IP) protocol stack to dynamically assign IP addresses to DHCP clients and to allocate TCP/IP configuration information to DHCP clients. This includes subnet maskinformation, default gateway IP addresses and domain name system (DNS) addresses.

I don't see how a switch at layer 2 would affect a broadcast domain. Switches separate collision domains not broadcast.