Lan in bridge2 cannot ping Lan in bridge3 (router is reset no default configuration)

RouterOS Beginner Basics
1

Hello I reset Mikrotik 951 to “no default configuration”, create two bridges , bridge2 and bridge3, add port eth2-bridge2 and eth3-bridge3, then add addresses
address 192.168.3.1/24, network 192.168.3.0, bridge2
address 192.168.4.1/24, network 192.168.4.0, bridge3

Why PC1 for example 192.168.3.5 in first LAN cannot ping PC2 192.168.4.5 in second

2

RB951G-2HnD incorporates Atheros8327 switch chip; see Block Diagram: https://i.mt.lv/cdn/product_files/RB951G-150611115818_150618.png
Multiple bridges is a documented error; see Bridges on a single switch chip: https://help.mikrotik.com/docs/display/ROS/Layer2+misconfiguration#Layer2misconfiguration-Bridgesonasingleswitchchip

Consider studying Atheros8327 features and revising design; see Switch Chip Features: https://help.mikrotik.com/docs/display/ROS/Switch+Chip+Features

3

So you’re using your RB951 as router … are PC1 and PC2 aware of it? I.e. do they use RB951 as gateway (either as their default dateway or at least as gateway specific to reach the other LAN subnet)? And additionally: some OSes (notably Windows) include firewall which by default blocks connections from IP networks outside their “native” LAN subnet.

4

So how I understand create 2 separate bridges (without NAT and without VLAN) that they can communicate each other on this mikrotik i cannot?

5

Hello no i’m not using it as a router, it was reset to “no default configuration.”
interface bridge
add name=bridge2
add name=bridge3
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/interface bridge port
add bridge=bridge2 interface=ether2
add bridge=bridge3 interface=ether3
/ip address
add address=192.168.3.1/24 interface=bridge2 network=192.168.3.0
add address=192.168.4.1/24 interface=bridge3 network=192.168.4.0

6

See post #3 again from mkx.

The moment you define 2 subnets, you’re using it as a router.
Why 2 bridges ?

And are your PC’s aware they need to pass over that device (=router) as gateway ?

I’ll put it otherwise:
If you have 2 roads and there is nowhere an intersection, you can never get from road A to road B.
Heck, cars on road B might even never know road A exists since there are no traffic signs to make them aware.
Get the analogy ?

7

To make things clear: as soon as ROS-running device has more than one IP address, it will act as router - passing IP packets between interfaces accroding to destination IP address.

Unless there are some rules (routing rules, firewall) which blocks that (but ROS default doesn’t have any of thsoe and you’re saying you didn’t configure them yourself).

8

Yes I didn’t configure them, it doesn’t have firewall, nat, rules, i read in forums that just i can make 2 lans in separate bridges and if it doesn’t have default configuration, they must saw each other. But may be this configuration cannot worked, Thanks all for answers

9

Thanks

10

You need a coherent plan.
How does the mikrotik fit in your network → provide a network diagram including where interent is from and what other devices involved.
Next figure out who your users and devices are
Then state what traffic flows they should have.
Without any talk of devices or mikrotik config, just traffic flow.