problem with publics ip

RouterOS General
1

Hi,

I have a public ip range (/25) in a Cisco router, I need to configure a Mikrotik to route the public IP thought it, but I can’t do correcly.
I have this.

CISCO 2600
PUBLIC IPS: X.X.X.128/25
ETHERNET: 192.168.0.24
STATIC ROUTE: PUBLIC IPS TO 192.168.0.25

WHEN I CONFIGURE IN A WINDOWS PUBLIC IP (X.X.X.129) WITH GATEWAY 192.168.0.24 WORKS CORRECTLY.

THEN IN MIKROTIK CONFIGURE THIS:
WAN: 192.168.0.25
LAN: X.X.X.129/25

IP ROUTE TO 0.0.0.0 GATEWAY 192.168.0.24

For this configuration I can ping to ip public and enter winbox thought internet, but mikrotik box can’t ping to internet.

Do I need to configure any firewall rule? or nat? I probe it without sucess.

Best Regards

2

As a rough guess: because your default route to the Internet is via 192.168.0.24, the Mikrotik router will choose 192.168.0.25 as the source IP address to ping from. Unless the Cisco router is set up to NAT that IP address to its WAN interface the ISP will discard the ICMP packet.

Does this work?

/ping 4.2.2.2 src-address=x.x.x.129

That way you’re pinging sourced from the Mikrotik router with a public IP address.

3

also, try to set pref-source of your default route to your x.x.x.129

4

Thanks with this works ok.

How do I need for use public ips in a router or PC connected to LAN using /32 addresses? pppoe?

CISCO------ROUTER1--------ROUTER2

CISCO WAN: x.x.x.128/25
CISCO LAN: 192.168.0.24/24

ROUTER1 WAN: 192.168.0.25/24
ROUTER1 LAN: X.X.X.129/25

ROUTER2 WAN: x.x.x.130/32
ROUTER2 LAN: 192.168.1.1/24

The idea is use router1 as a PPPoE server

Best Regards

5

If you want to set it up as a PPPoE server, that will work. The manual covers that.