Zentyal DHCP multiple internal interfaces help

[aberator]

Hello,

I'm trying to figure something out. My setup is as follows: Core2Duo @3.06GHz, 4GB DDR3, 80GB SATA, 3 NICs (2x10/100MB, 1x10/100/1000MB)

My first NIC (eth0) is connected to my ISP via PPPoE (10/100MB). I want to use the other NICs for internal use: eth1 - 10/100MB, eth2 - 10/100/1000MB.

What I'm trying to do is to setup my other 2 NICs (eth1, eth2) as internal interfaces with DHCP enabled on them.
I tried the following:
- eth2: 192.168.0.1, DHCP server enabled with pool 192.168.0.100-150
- eth1: 192.168.0.2, DHCP server enabled with pool 192.168.0.151-200

The thing is that if I only set eth2 then everything is working great. If I also set eth1, everything gets screwed to hell. No DHCP leases, no ping to 8.8.8.8, no ping to Zentyal server, everything is messed up. Once I go to Network->Interfaces and change eth1 to "Not set" everything works great again. The same if I only set eth1, leaving eth2 "Not set".

Suggestions?

Thanks!

[Sam Graf]

Hello, and welcome.

Assuming these are /24 addresses, I believe the two interfaces will have to be on different subnets. Eth1 could provide 192.168.0.0/24 and eth2 could provide 192.168.1.0/24, in other words. But having both interfaces on 192.168.0.0/24 won't work, I don't think.

[christian]

Sam, you are perfectly correct!
either IP ranges have to be different or netmask must be changed but this is going to be too complex with very little added value if any.

@aberator: is there any reason why you target such design?

[aberator]

Thanks Sam,
Any idea how can i put both interfaces in the same subnet? Maybe set eth1 to bridge? Or setting /25 subnets on eth1 and eth2?

@christian: yes, trying to physically separate my network by NIC speed (100mbit and Gigabit) but keeping them in the same network to share files between them and such.

[christian]

OK, clearer, kind of, although I don't really understand the goal behind this 
I mean that you can mix, without any problem, devices with 100Mb and 1Gb interface on same network (assuming switches are Gb compliant of course 

There is are multiple things you can do depending on what you really want to achieve.
To me, benefit of adding 100Mb on top of the 1Gb is very low. The way to achieve it is to perform NIC bonding
Another goal could be higher availability: in case one NIC fails, the other one is still up. Here again, bonding will do the trick.

If you do want to split networks, /25 will provide you with 2 networks of 126 IPs but keep in mind this requires all devices to have this conf.
Another aspect of such strange design: all communication between devices on your network not targeting your Zentyal server will have however to go through Zentyal server 
 

[christian]

I forgot to add that bonding 2 interfaces with different speed is not a good idea if you have any performance concern. Or you will have to look carefully at bonding mode 

[aberator]

Thanks mate! You actually cleared many things!

Cheers!

[christian]

what you can also do without any problem is to allocate 2 different IP on 192.168.0.0/24 network for you Zentyal server, one per NIC.
Obviously only one will have DHCP enabled but server can be reached using any of these 2 addresses.
Is there any added value of such design, I don't know