I’ve got two 3G USB modems for internet. I also got two RB751 devices.
I wan’t to have both 3G modems working (connected) and do failover from one to another (if first link drops).
I tried to add both USB 3G modems to one router via USB HUB, they worked, but they could not be both active.
If one dialed up and connected, then second one was waiting and connected only then, when the first one disconnected.
I think this is some kind of limitation of RouterOS? or i must to make some kind of additional config ?
So i now have my primary router A connected, which is working and it has configured wifi, lan, dhcp etc. with NAT on ppp-a interface.
Also have second router B with default config + ppp connection with NAT on ppp-b interface.
I connected A (port 5) with B (port 5). If i setup NAT on A on port eth5, then changing routing marks (with scripts) or routing distance the computers can use either internet through A or B (some kind of failover)
but then i have two NATs (on B - ppp-b to LAN → on A - eth5 to LAN) and i discoverd that some webpages, services isn’t opening, or opens very slowly and other strange things.
How could i avoid two NATs? using some routing or what? i think it’s a bad idea to have two NATs.
And i also want to enable some port forwarding (on A from ppp-a to LAN it works), but from B ppp-b to A LAN it doesn’t work. i tried to set up DSTNAT to A LAN IPs (didn’t work) or to A eth5 IP, then on A tried to dstnat eth5 to LAN, either didn’t work. any ideas?
my friend gave me idea, that i should add A and B with simple config and NAT, and then add router C to A&B and to C add LAN. And in router C make only routing, not NAT. But i think it’s stupid to have two devices or even three, knowing that routeros ir very powerful, just i don’t know how to use it.