Two providers, one router with a switch board, is that possible?

Question

Cisco

Here lies cisco 1921, but there is nowhere to shove it.
Here is a thought, the gateway will die, you will have to configure it, but how to configure it for two providers if it has only two ports. Well, here the sub interfaces and the managed switch came to mind. After that I thought. But what if you also buy a switch panel and do not strain the existing switches and do not pull an extra wire from the router to them.
And then something like this came:

Red wire - providers. Yellow - locale.
After that, I threw the circuit already in the packet tericer (I used a repeater, because without it it does not allow the wires to be closed to itself) It turned out such a working circuit.

Everything is pinged.
- - -
But the question arises. And is it right to do so?

Answer 1

After connecting a separate panel, its interfaces will appear in the cisco itself and there is no need for a scary bicycle with a loop.

Answer 2

Regarding the use of a loop - as far as I remember, this method is really used, but in the case when it is necessary to combine the interfaces of two *ESW modules into one L2 domain. In your case, this is not necessary.

And is it right to do so?

Judging by your comments, you yourself understand that 4ESW is a switch (switch). For what purpose do you plan to connect uplinks from providers to it? How can a switch help you? You need to route traffic from the local network to different uplinks depending on certain conditions, and NAT accordingly. Connect the uplinks of providers to the built-in gigabit ports (which work as L3 interfaces), and the cable from the local network to the 4ESW card.

And if, for example, you insert something like HWIC-4ESW. Is there an IP address on the port you can register?

If I remember correctly, the procedure is as follows: a VLAN is created, the required interface is registered as an access port in this VLAN, an SVI corresponding to this VLAN is created, L3 settings (IP address, etc.) are written on it

After that, I threw the scheme already in the pocket tericer

Packet tracer is good for initial learning. I do not think that it makes sense to use it for the purpose of testing the performance of the network design, especially when there is a specific hardware.

Answer 3

Something tells me that after installing the board, new interfaces will appear in the router that can be configured without any additional crutches, like a loop wire.

Answer 4

the standard situation
on the switch is to make 2 vlans (prov1 / prov2), give one port each to these vlans, plug laces from providers into these ports.
make the port towards the router trunk and allow the passage of the specified vlans in it.
from the side of the router on the interface (into which the switch is plugged), create 2 subs with the specified prov1/prov2 numbers.
these subs are full-fledged l3 interfaces