Routing between bridges on Mikrotik

RouterOS Forwarding Protocols
1

Hi there,

Could somebody help me please? I have very simple topology (attached: Mikrotik CRS125 has two bridges (bridge_517 and bridge_523). In subnet 10.5.23.0/24 we have bridge (zyxel keenetic) where default route is Mikrotik (10.5.23.253).
The problem is I’m not able to access hosts in subnet 10.5.23.0/24 from hosts in subnet 10.5.17.0/24. If I send trace Mikrotik (10.5.17.1) says the host in subnet 10.5.23.0 is unreachable, BUT I’m able to ping those hosts from Mikrotik winbox.
And I’m able to access Zyxel interface (10.5.23.1) from host in subnet 10.5.17.0/24.

I tried permit ALL traffic on firewall, checked routes and so on. It seems routing between bridges is not working =|

Could someone advise something please?
mikrotik_zyxel.jpg
routes.jpg

2

Do not use two bridges, one is enough to achive what you want to do.
If you must/want/need to use two bridges, be aware that they do not communicate with each other until you set that up.

3

Seriously, why tf are people still doing this dumb double/triple/multiple bridges crap on modern-day Linux DSA? Have they not received basic education and training in Linux networking or something?

4

Thank you so much for your reply. I tried to use on bridge, but the problem is still persist =(
one_bridge.jpg

5

Your original network diagram doesn’t show the whole picture (no mention of the 172.16.x.x subnets, or the router at 10.5.17.253). What is the default gateway of the devices on the 10.5.23.0/24 network? Does the target device accept ICMP requests from outside its subnet (hint Windows doesn’t)?

6

I’ve managed to fix the issue:

  1. Hosts in 10.5.23.0 subnet were configured to use wrong GW IP address. I set it to 10.5.23.253.
  2. Traffic between bridge_517 and bridge_523 works fine.
  3. Regarding my another branch (subnet 172.16.177.0). I configured p2p link between router 172.16.177.254 and mikrotik 10.5.17.1 through subnet 10.192.34.252/29 and set routes.
    Now everything works fine.
    Thank you very much for respond.
7

I see one reason to have two bridges, it’s using Jumbo frames over LAN with using ordinary frames of WiFi in same device. Is this possible with out split to two bridges?