RouterBOARD RB751G-2HnD and NetGear GS108T Switch

RouterOS Beginner Basics
1

Hi there,

My first day (and night with a routerboard-device) and my first post here. Apologies if I haven’t lurked enough nor googled enough.

My setup is the following:

Internets with cable modem
      |
RouterBOARD RB751G (with RouterOS 5.21)
192.168.242.1
      |                             |
box1                           NetGear GS108T Switch (mgmt on 192.168.242.199)
Ethernet                      Ethernet 
192.168.242.20                      |
                                    |
                                    box2
                                    Ethernet
                                    192.168.242.245

Netmask 255.255.255.0
NAT and DHCP-server and DNS-forwarding enabled on RouterOS.

Both machines is assigned IP-addesses from routeros-box, using the same DHCP-scope.
box1 is working just brilliantly, accessing the internets and everything.
box1 can also ping and ssh to box2.

box2 can ping box1 and ssh.
box2 can’t ping routeros-router, nor can it access the internets.

Connecting box1 to the Netgear Switch it gets the same issues, no internets, only local access and no access to routeros-box. Connecting box2 to routeros-box directly makes this access the internets and all is well.
This leads me to think there is some sort of issue with the routeros box and the Netgear Switch.

I have tried:

  • disabling all VLANs on switch.
  • factory reset switch.
  • upgraded firmware on switch.
  • fiddled with Auto negotiation/Link speed/Full half-duplex/Flow Control (only switch) on both routeros and switch at no avail.
  • replaced all cables.
  • tested several switch-ports on both router and switch.
  • enabled/disabled jumbo-frames on switch.
  • tried arp enabled, disabled, and proxy-arp on routeros.
  • removed all “deny”-rules in routeros firewall.


    And now I’m out of ideas.. What more? Is it something easy I’ve missed I guess?

/Gustav

2

Are you sure about your Default Gateway in your switch?

Try a tracert from your box to the router.

Regards,

3

Thanks for your reply.
Yes. The NetGear Switch is assigned IP from the RouterOS-router as well, including default gateway.
From the NetGear interface: Default gateway 192.168.242.1

box2:~ user$ traceroute 192.168.242.1
traceroute to 192.168.242.1 (192.168.242.1), 64 hops max, 52 byte packets
 1  * * *

and

box2:~ user$ netstat -ar
Routing tables

Internet:
Destination        Gateway            Flags        Refs      Use   Netif Expire
default            192.168.242.1      UGSc            1        0     en0
127                localhost          UCS             0        0     lo0
localhost          localhost          UH              1        0     lo0
169.254            link#4             UCS             0        0     en0
192.168.242        link#4             UCS             6        0     en0
192.168.242.1      0:0:0:0:0:0        UHLWIi          8      157     en0   1094
...
4

Sorted it. I did not have a MacAddress on my bride in RouterOS on which I’ve added my default gateway. Therefore the client-devices did not know where to return packages.