Routing between two subnets

RouterOS General
1

Hallo together,

here is my current situation:
Subnet 1 - 192.168.0.0/24 connected to RB750GL via ether2 with IP 192.168.0.254
Subnet 1 has an Gigabit Switch with other clients, this Switch is connected to RB750GL with ether2.
Subnet 1 has a DSL Router for Internet access (IP 192.168.0.240) by ISP 1.
Subnet 1 gateway is 192.168.0.254.

Subnet 2 - 192.168.128.0/24 connected to RB750GL via ether3 with IP 192.168.128.254. The subnets includes only one VM connected to ether3.
Subnet 2 has no switch therefore ether4 is configured as a switch port for the master port ether3.
Subnet 2 has also an DSL Router for internet access (IP 192.168.128.240) by ISP 2. The DSL Router is connected on ether4.
Subnet 2 gateway is 192.168.128.254.

Subnet 1 has internet access via ISP 1. Subnet 2 should use the same ISP.
At the moment I cannot ping between the different subnets.

Ping VM 192.168.128.90 —> 192.168.128.254 OK connected directly
Ping VM 192.168.128.90 —> 192.168.128.240 OK connected via ether3/4 switch
Ping VM 192.168.128.90 —> 192.168.0.254 OK both interfaces are part of same routerboard
Ping VM 192.168.128.90 —> 192.168.0.240 FAILS!
Ping VM 192.168.128.90 —> google.de FAILS! but DNS can be resolved to IP

Tracerout sends all packets to the correct gateway 192.168.128.254 but from there nothing is going on.
Is there missing any route between the subnets?

Here is the /ip route print output:

0 A S 0.0.0.0/0 192.168.0.240 1
1 ADC 192.168.0.0/24 192.168.0.254 ether2-local-ma… 0
2 ADC 192.168.128.0/24 192.168.128.254 ether3-local-ma… 0

No firewalls are set.

Any advices? Thanks, toby

2

Do you have any NAT rules enabled?
Can you ping to all subnets including the internet from the router itself?

3

“/ip firewall nat print” gives an empty output.
Yes I can ping google, 192.168.0.240 as well as 192.168.128.240.

Very confusing to me! Do I need static routes in the clients? The default gatewy from DHCP(x.x.x.254) must be enough?!

4

The routes you have should be more than enough, and the gateway on each subnet appears to be fine.

Have you tried looking at the Torch for each interface on the MikroTik while pinging, to see where the packet(s) might be getting lost?

5

I see incoming icmp from ether2(192.168.0.0/24) but not outgoing on ether3(192.168.128.0/24) for destination 192.168.128.240.

Routerboard seems to swallow the packets!

6

what you need is static route for your ISP1 dsl router for subnet 2 (192.168.128.0/24) with gateway 192.168.0.254

otherwise ISP1 dsl router don’t know return path for your subnet 2

7

I did set this route. But apart from that I should be able to ping between clients in two different subnet without using ISP 1 or 2 !?
This is the main rason for my problems I think…

8

It is a problem of ICMP :open_mouth:
The webinterface of a device in the 192.168.128.0/24 subnet is reachable!!!

9

is there anything else you configured on router? maybe you should try to reset configuration and set only ip+routes and try it out, if it works, set the rest

10

DHCP and DNS, nothing else.
Is there a possibility to export the complete configuration and edit them manually via notepad? In other words I delete everything not set by me…

Doing a complete reset would mean a lot of work :frowning:

11

you can do export of total config, but it exports also stuff that is set by default, it will be alot of lines :stuck_out_tongue:, try

/export file=config

then you will find config.rsc in /files, you can download it with ftp or drag&drop from winbox

12

Ok the export process was successfull and yes the file has many lines :smiley:
But while trying different things I recognized that ping is possible but only to client 192.168.128.90 which is connected to ether3. The second device in subnet 192.168.128.0/24 is the DSL Router 192.168.128.240 (ISP 2). This one is not pingable from subnet 192.168.0.0/24. It is connected to ether4.

The error is perhaps somewhere in the switch configuration?

/interface ethernet print

NAME MTU MAC-ADDRESS ARP MASTER-PORT SWITCH

0 ether1-gateway 1500 00:0C:42:C1:F9:9D enabled none switch1
1 R ether2-local-master 1500 00:0C:42:C1:F9:9E enabled none switch1
2 R ether3-local-master 1500 00:0C:42:C1:F9:9F enabled none switch1
3 RS ether4-local-slave 1500 00:0C:42:C1:F9:A0 enabled ether3-local-master switch1
4 ether5-local-master 1500 00:0C:42:C1:F9:A1 enabled none switch1

I thought with this configuration ether3 and ether4 are a virtual switch group? This switch is connected to the routerboard via ether3 operating as a gateway with IP 192.168.128.254.
Do I make any mistakes?