How to register a route so that clients of another router can be seen?

Question

Computer networks

Given:
Mikrotik hexs (dhcp 10.0.0.0/24 255.255.255.0)
Eth1: PPOE provider for Internet access Eth2
-Eth4:
Eth5 clients: free

Huawei HG8245H-256M (dhcp 192.168.100.0/24)
internet from another provider.
Eth1-eth4: clients

Essence of a question. I want to be in the Huawei network, have access to Mikrotik clients. Simply put, the huawei gave me the address 192.168.100.22 on the laptop and I want to reach 10.0.0.10 from the laptop (which lives on the Mikrotik network) (for example, I connected both the Mikrotik and the huawei with a cable, and I kind of need to register some kind of route on the huawei, but not sure). How can I check all this? If possible, explain as simply as possible (for a lamer)

Answer 1

I connected both Mikrotik and Huawei with a cable, and I kind of need to register some kind of route on the Huawei

Not only on Huawei, but also on Mikrotik it is necessary to register. Let's start with Mikrotik, let's say we plugged the cable into the ether3 port;
on the command line:

/interface bridge port remove [find interface="ether3"]
/ip address set address=192.168.100.254/24 interface=ether3
/ip route add dst-address=192.168.100.0/24 gateway=192.168.100.1

We set up Mikrotik, but it's useless, here https://lan1.by/qa/8078/ they write that Huawei is so stupid that it doesn't know how to static routes in the LAN at all. I don't have Huawei to check, I have to believe what they write.
Of course, you can file NAT on Mikrotik, then clients from Mikrotik will go to the Huawei network, but not vice versa.
Possible solutions:
(1) (expensive option) throw Huawei in the trash, buy a smarter router to replace it;
(1a) search if it is possible to flash ddwrt on Huawei; screw up with the firmware and still throw it in the trash;
(2) (cheap option) make two identical local networks, by means of Mikrotik, prohibit DHCP from going in any direction between routers, make non-overlapping address ranges on two DHCPs;
(3) (crisis option - for a momentary solution) do not change addressing, file NAT one-to-one in both directions on Mikrotik; somehow it is possible, but I don’t even want to spend a couple of minutes googling this option, sooner or later some new problems will arise from it in administration.
Upd.: By the way, there is another option.
(4) if there are three and a half users in the LAN behind Huawei, then you can go through all of them and on each PC manually register the route to the Mikrotik LAN through the Mikrotik gateway. In this case, Huawei can remain dumb and not know anything about the other local network. Mikrotik must be configured as I described above.
On Windows users:

route -p add 10.0.0.0 mask 255.255.255.0 192.168.100.254

But if there are a hundred users, then you will be tormented to prescribe each.

Answer 2

When you connect 2 routers with a cable, you will need to select the router configuration option:
1. router 1 will be a member of the LAN network of router 2 (i.e. the first one will have an address on the LAN interface from the network of the second one). Router 1 is slave, router 2 is master.
2. Router 2 will be a member of the LAN network of Router 1. Router 2 is a slave, Router 1 is a master.
3. organize a separate subnet for routers, in which there will be only 2 hosts. Both routers are equal members. This option should be used if you had not 2 routers, but more with the prospect of increasing their number (for example, combining a branch network of an enterprise).
All three points imply the allocation of at least one (slave) router (in step 3 on both) of one interface (the one with which you combine routers) into your own VLAN (on such devices this can be called differently depending on the manufacturer's imagination).
In this case, you may need to add a firewall rule on the slave router that allows routing between networks.
Routing by options:
1 and 2. On the master router, you need to register a static route to the network of the slave router. On the slave, you do not need to prescribe anything, because. he is already a member of the leader's network and the route will appear automatically for him.
3. On both routers, you need to register routes to the neighbor's network.
As you can see, in all options, the router is required to support certain capabilities: the master needs the ability to add static routes, the slave needs VLAN support (for option 3, both options for both routers).
Usually at home, when 2 routers are combined, they simply use the WAN interface of the slave to connect to the master. But in this case, only the master has access to the Internet and the network behind the slave goes to the Internet through the master. You have your own Internet on both routers and this option does not suit you.