sobayorg wrote

... it is connected to the ISP router, because the main M4 node have both ports busy ...

@sobayorg 

To help with finding solution, I would need you to answer this for me:

1. What is connected to second port of Main Deco?

2.  Do you have iPTV function enabled or disabled in Deco mesh? See How to Configure IPTV function on Deco? that explains where this setting is.

@Alexandre. 

1. another deco 

2. disabled

i might add, the network works fine but one room that is far.

my connection now [old router]----<[ISP Router]>----[Main Node]>----[2nd Node]

                                                                              [Main Node]>>>[3rd Node]

but i need to change the ssid when im in old router room

what i want [ISP Router]>----[Main Node]>----[2nd Node]>----[old router]

                                           [Main Node]>>>[3rd Node]

and quick and smooth network switching and one ssid

@sobayorg 

Then, I may have an easy solution for you.

Get generic 5-port gigabit switch, they are quite cheap nowadays. Connect it to second port of Main Deco, you now have 4 available Ethernet ports coming from Main Deco instead of one. 

You can use one port on switch to connect your "another deco," and will be left with 3 available Ethernet ports coming from Main Deco.

Retire your old Huawei router. Instead, buy additional Deco M4 or M5, and connect it by Ethernet cable you already have to that new switch. 

im planning to buy an additional M4 nodes but for time being...

is it possible to connect the old router to a secondary node that is connected to the main node via ethernet?

@sobayorg 

Yes, it is possible, but that won't give you same SSID and seamless mesh. Instead, connect additional M4 you plan to buy to a secondary Deco node you already have, using Ethernet. That should work.

In any case, I suggest you decommission your Huawei router and think how can you expand your WiFi mesh without it.