We have 1 main office and 2 additional. I need to set up site-to-site vpn. I have created L2TP server in main office, L2TP clients in branch offices, added static routes both in main and branch offices. Now i can ping servers of main office from branch office PCs and vice versa. But I cannot reach resources of branch office 1 from branch office 2. I suppose i need to add some additional routes or allow traffic to go through the main router. What should i do to allow traffic flow from branch office to branch office?
Just guessing, as you didn’t provide any configuration details: most probably you need to set arp mode to proxy-arp on your main office router LAN interface (possibly a bridge) so that it proxies ARP requests between both branches.
Or routes are missing so the routers do not know how to reach the networks behind the peering router.
Hope you have not made the bridge as pukkita assumes…