Hello guys,
I have a net with two subnets, 192.168.92.0 and 192.168.1.0.
Internet outgoing is through 192.168.92.0 subnet, and on 192.168.1.0 subnet I have a Cisco 1800 to connect a VPN.
The Cisco Address is 192.168.1.1
VPN adresses are 172.17.255.0
Pc Systems gateway is 192.168.92.1, the address of ppoe router, not the routerboard.
I made a Ip route of destination address 172.17.255.17 to gateway 192.168.1.1 with gateway check = ip, type unicast.
When I try to reach 172.17.255.17 from routerboard traceroute tool there is no problem and the work is well done, but
when I try to reach 172.17.255.17 from one pc, if I make a tracert from pc I see the first jump is to 192.168.92.1 and not to
192.168.1.1 as it is configured in routerboard.
Are you so kind to say me what I´m doing wrong?
Thank you so much.
The problem is that the LAN devices don’t know any routes but their default GW - the pppoe modem. The default GW of the LAN needs to know that the 172.17.255.0 network is down through the Mikrotik, not up through the Internet.
The quick fix is to create a static route in the pppoe router: 172.17.255.0/24 gateway = 192.168.1.X IP of Mikrotik…
Or for a clean solution, make the Mikrotik take over 192.168.1.1 and do the PPPoE client on the Mikrotik (put the ISP modem in bridge mode)
For a slightly less clean solution if you can’t do bridge mode on the modem, create a new LAN range: 192.168.2.0 and move your LAN devices into that network - let the Mikrotik be default GW for 192.168.2.x network. Of course you’ll need a route in the pppoe modem for 192.168.2.x via the Mikrotik, or else you’d need to do masquerade in the Mikrotik - double NAT should be avoided, though, so it’s better to put the static route in the modem.
Either way, there won’t be hairpin routing and ICMP redirect messages flying around as there would be with the ‘quick fix’
Thank you very much Mr. Zerobytes.