I have a DSL router on my LAN as an internet gateway, but I want to use a mikrotik router as my default gateway on this LAN, which will then use the DSL gateway as its gateway. This config seems to introduce latency problems basically breaking the network.. why and is there a workaround. there is a VDSL mode on the DSL gateway I’m playing around with. I don’t want to remove this gateway as it is VoIP aswell
How have you connected and set this up?
The simplest solution is to reset MikroTik to defaults, connect the cable from your modem to port eth1 on the Tik and all your other devices to the rest of the ports. By default MikroTiks are configured to expect uplink on the eth1 so they have a DHCP client there, NAT traffic from other ports to this single one and serve DHCP on all other ports for client devices.
This is exactly how I’m now using my hAP ac² to test it and learn MikroTik.
I’m wanting to keep everything on the same subnet which is the difficulty - having 2 routers with different WAN interfaces (wan and internet) on a single LAN. I could route between them, and be on different subnets, I guess that could work. I’m going to try a VLAN config using a separate subnet for my default route from my wan router to my internet router, that may work..
If a router receives a packet with a source address from some subnet, and the routing tables indicate that the packet should be forwarded via a gateway (another router) in the same subnet, it usually forwards the packet through that gateway but it also informs the sender using an icmp packet that a better router for that destination is available in the same subnet. Use /tool sniffer on the interface through which that subnet is connected to save the traffic into a file which you can then open using Wireshark (or run Wireshark directly on the PC from which you’ll ping) to see whether the icmp packet is sent and what is the delay between reception of the original packet and its sending forward. This will show you whether the delay is caused by Mikrotik or by the device’s reaction on the icmp packet.
However, such setup is awful 
I hope you at least run only one DHCP server on it.
Your last post has quite obfuscated what prevents you from having two LANs, can you diagram your network topology? A photo of a handmade drawing is usually sufficient.
So I have been able to put my VDSL connection in it’s own ‘interface group’ on the soho router, with its own IP, on a VLAN, which my mikrotik router (default gateway (running the only DHCP server)) can reach on that VLAN IP as a default route. I have a masquerading rule on the mikrotik router for the VLAN IP, which works fine (double NATed for now)… but… connecting to the VDSL router using it’s non VLAN IP (192.168.6.3) is very slow and barely works from my PC connected to the switch… but this IP should be on the LAN bridge interface for my mikrotik router, and not go through any routing…?
I have a similar setup in a different location.. is there a best practice in this situation? can I have 2 gateways on a LAN and pick either through DHCP successfully? The problem is if I have the VDSL router as a LAN host/gateway, and I use my mikrotik (which has default route through WAN) as my default gateway on my PC, connecting to the VDSL LAN IP is very slow…?
You have drawn the physical topology, i.e. cabling, and a few IP addresses. But the logical topology is probably missing on the drawing. As you mention the VLANs in the description, I would expect two distinct subnets topass through the switch, one in a tagged VLAN with DHCP-server running at the modem and the second one untagged, with dhcp-server running at the Mikrotik, and use the tagged one as Mikrotik’s secondary WAN and the untagged one to connect the clients.
That way, you wouldn’t have any conflict of gateways, and no icmp redirections as devices would use Mikrotik’s IP in the second subnet as a gateway, and the Mikrotik would use one of the WAN gateways depending on your other settings.
yep I’ve configured it as you mention - internet traffic from the dsl router is on VLAN 11 with 192.168.16.3/24 (although no DHCP..)
I’ve cleaned up the diagram a little
So my issue I think was referred to in your first reply Sindy - having my dsl router in its normal config as a NAT gateway but having my mikrotik router as the gateway set by DHCP and trying to have the option to I guess route within the same subnet.. this seems kinda dumb and I understand why this would cause problems, I dont really understand specifically what was going wrong though, if I try to connect to 192.168.6.3 from my PC when my GW is 192.168.6.5 it takes forever to load… - I thought (assumed?) packets on the local subnet weren’t sent to the gateway..?? even in my current config where the dsl interface has it’s own subnet and VLAN. Just wondering from a technical perspective why this is the case? - I can reach the dsl routers VLAN IP through NAT on my Mikrotik fine.. (haven’t had the courage to try bridging the DSL connection just yet…)
In this setup only my mikrotik can be gateway, but I’ll play around with route settings to decide default route and redundancy, I’m getting foreign google location settings for some reason through my WAN VPN GW, so I’ll set those hosts to my local internet I guess 