DHCP reservation for the same device in different nets (green and blue)

network
dhcp

(Guillermo Fekete) #1

NethServer Version: 7.5
Module: dhcp

As an alternative to my first net design (see dhcp in dmz), I’m evaluating to use the router as dns and dhcp too. But I want to be able to reserve an ip in each net (green and blue) for the same device. Is it posible?
It seems not. Having reserved the ip for the green network, when I try to reserve for blue, it indicates that the mac is already reserved.

Thanks for your help!


(Markus Neuberger) #2

You are right, the entries are saved without roles or interface, just with MAC and IP:

http://docs.nethserver.org/projects/nethserver-devel/en/v7/dhcp.html#ip-reservation

What about two NS gateways:

grafik

This way you could have reservations on blue and green because they get the reserved IP from different Nethservers and there’s no need for DHCP relay.

EDIT:

After thinking about this configuration, there may be still problems because the same host has different reserved IPs.
May I ask why you need the same network device on blue and green with reservations?


(Guillermo Fekete) #3

Thanks @mrmarkuz!

Basically, I want to be able to prioritize the traffic of the Institute’s authorities. As they are also teachers, their notebooks are not always in green.


(Giacomo Sanchietti) #4

No it’s not, but you can add an alias on the PC itself.

In this case I would go with 2 different green networks.
Then, you can prioritize the traffic (or even block it between green) using CIDR inside the firewall rules.


(Michael Kicks) #5

@guillermofekete which are the uses of these two network segments?


(Guillermo Fekete) #6

Hi!
The green (wired) segment is for administrative use (Authorities, preceptors, Administrative Staff, etc).
And the blue one (wi-fi) is for students, teachers and guests.

@giacomo, my poor knowledge about networks (I’m being honest here, please do not misunderstand me) does not allow me to be sure if I’m understanding you. With two greens, would not I need the double reserve for the device?

Thank’s you all!


(Michael Kicks) #7

So why “administrative users” should connect to Students/Teachers/Guests?
Are there any access point on Green network segment?


(Guillermo Fekete) #8

Hi! Thanks for your time!

Because

I don’t need/want to them be able to use services for green (AD, File server, database, etc). I just want to be prepare to give them special traffic treatment.


(Michael Kicks) #9

According to your post, teachers should not be part of green lan segment; only of blue one. Therefore, you should deploy the connection only on blue…


(Giacomo Sanchietti) #10

No, a device can always have only one reservation.

I agree with Michael.

Enable the DHCP both on green and blue and you’re done.
If a specific device from blue needs to access a service on the green, just create a rule for it.