Configuring 2 network card

RouterOS General
1

i have 2 Nic cards configured on MT with ip address 203.x.x.1 and 203.x.x.2 with gw 203.x.x.4 when i ping from internet i can get both the IP’s. now the problem is, I have a system with legal ip 203.x.x.4 which is connected with a cross cable to 203.x.x.2 directly, but when i try to ping 203.x.x.2 from the system i cannot get the IP secondly even if i ping from the internet i cannot get this system.

  1. Is there any config i have to do on the MT ?
  2. What i have done will it work on MT (does it support 2 Nic with the same subnet IP address)

Can anybody help me in this.

2

You can NOT have two different interfaces with ip addresses from the same subnet…

3

So now it there any way in MT were we can make one interface un-numbered like how we do on a cisco router.

Rgds
Darshan

4

What do you actually want to achieve? Perhaps you could explain a bit, so someone could make suggestions for a correct design/config.

5

The Senario is as Follows:

The ISP has given me a Fibre Connection with 3 IP 203.x.x.89, 90, 91 with subnet mask 255.255.255.240 and Gateway 203.x.x.87

I have configured:
ether1 with IP address 203.x.x.89
ether2 with IP address 203.x.x.90
And Gateway 203.x.x.87

Now i have a system which i want to give the third IP 203.x.x.91. The traffic going from this IP to 0.0.0.0 has to be routed thru the MT box.
In this senario how do i configure the MT box.

Pls note that the system has to be on a Public IP.

Darshan

6

it is not possible to have two interfaces with IP addresses from the same subnet. not on RouterOS or anywhere else. this cannot work, you have to study TCP/IP basics.

7

It could be achieved with bridge, and this is the suggested method (and yes, it has firewall)

But if you do not want to, I have think of one hack. I am not really sure if it will work, but I would give it a try:

  1. you must setup the internal computer to have default gateway 203.x.x.90. Does not matter which netmask will it have
  2. setup a correct address with a correct netmask on external router’s interface. Also setup its gateway
  3. switch the external router interface to arp=proxy-arp mode
  4. add the x.90 address with netmask of 32 and with 203.x.x.91 as the network address on the external interface of the router

Maybe it will work…

If this method will not help, I have another one in mind using Universal Client :slight_smile:

8

IMO bridge will be the best and easiest way to do it
You just have to bridge two NICs on one box, connect your server to one interface and ISP’s cable to another (doesn’t matter to which one), set gateway on server (.87) and thats all.. now you can configure firewall on that box. You may also want to give an address to it (say 89, when your server is .90 or .91) to have access via ssh or winbox. And you still have one IP address left :wink:

9

proxy-arp?