PC Action wrote

Is it possible to configure the dhcp on this switch? Or is it not possible on this switch and do i have to work with a router/modem before the switch?

No, the TL-SG3424 is a L2 switch, it has no DHCP server function. You need to set up a separate DHCP server.

If its not possible, what mode/router do you advice where i can configure 3 different dhcp ranges?

How do you realize DHCP services with the 3 VLANs of the Juniper? Could this DHCP server not serve another IP range, too? If not, I would recommend a Linux-based system, either a server system or some SoC running Linux. This would give you any flexibility needed to set up any environment one can think of.

I don't still understand why you do not configure the fourth DHCP pool on the Juniper, which already provides DHCP services for the other three VLANs?

Configuration of the DHCP server on a router depends on the DHCP software it runs. But with almost all DHCP servers, it is just a matter of defining the IP address range, interface and lease time. How to do this depends on the software you use for your router or the Juniper switch.

As for the T2600G-28MPS: this is the new model name for the TL-SG3424P. It is still a L2 switch with almost the same functionality as the TL-SG3424P. The T2700 series are the L2+ switches with a DHCP server on board.

As to your question how to use VLAN1 printers from VLAN2: you need to set up inter-VLAN routing. This can be done either on the router or the Juniper or the T2600G. Just define interfaces for both VLANs, assign those interfaces an IP address from the subnet used in the VLANs and set up static routes. See the User's Guide for examples how to do this. There is also an older post somewhere in this forum in which I gave step-by-step instructions how to setup inter-VLAN routing, just search for it.

I see. I would recommend a Linux-based router (e.g. a fast hardware with Debian or LEDE) if you are UNIX-savvy.

As for inter-VLAN routing I found the post, it's here: http://forum.tp-link.com/showthread.php?99115-Route-between-VLANs&p=211076&viewfull=1#post211076

PC Action wrote

Do you know a good router? But even it is with a unix system on it, is it still posible to configur it through a web-based platform?

If you want a web UI, take a look at the EdgeRouter and/or EdgeRouter-X from UBNT.

Because to only work with commands its alleady been to long ago..

For advanced settings you would even need to go to the command line interface (CLI) on EdgeRouters and any other UNIX-based system, too, albeit for standard procedures they offer a nice and also powerful web UI.

Would it be possibl to make a DHCP server on a raspberry-pi?

If it runs Linux: sure. But I have no idea wether it supports features like hardware off-loading, so before choosing a platform for routing make sure it will achieve the bandwidth needed. For example, the EdgeRouters perform with up to 300 Mbit/s NAT throughput on their interfaces in standard (web UI) config, although this can be raised up to 900 Mbit/s NAT throughput if hardware offloading is enabled through the CLI.

I don't know RasPi's features nor even their architecture, so can't give a recommendation.