Hi,

apologies if for my basic knowlege but I am looking for some help with the following.

I have just bought a RB450 and it is the first time I have seen the OS. I have managed to connect to it, assign IP's to 3 of the interfaces in the following configuration;
eth01 - 192.168.1.1 - this interface provides DHCP with a range of 192.168.1.100 - 200
eth02 - 81.187.113.60 - this is an address on an existing network which has access to the internet.
eth03 - 10.40.10.10 - this is an address on a second existing network which has access to the internet.

I have set a route and firewall rule in NAT so that any devices which recieved a DHCP address from eth01 can get out on the internet using eth02. I can then manually edit the route and rule so that it connects to the internet using eth03.

What I would like to do is have a situation whereby it used eth02 as the default route but, if the internet loses connection it will failover onto the eth03 network.

At the moment this is in a test environment but once I have this working I will be installing it in a real life situation with routers on eth02 & eth03 rather than as it is at the moment but then end result would be the same.

Any help would be greatly appreciated.

It's easy, check out this example:
http://wiki.mikrotik.com/wiki/Two_gateways_failover

Hi,

many thanks for that. As I say, this is all new to me. I have tried what you said and applied the following;

/ip route add gateway=81.187.113.1 check-gateway=ping
/ip route add gateway=10.40.1.1 distance=2

However, it seems to have stopped all internet access now to either network. Apologies once more if it is mee being "thick".

Also, at this stage each network has different DNS servers so how do I get around that? Maybe that is the problem.

Have I made an obvious mistake?

You have different masquerades/src-nats on each interface, correct?
/ip firewall nat

Hi Guys,

Good news, I have figured out the problem. Basically the 2 networks had different DNS servers so I added them into the DHCP server settings and it worked fine.

Thank's for your help with this. I am going to try something a little more complicated now so no doubt I will post another question soon!!