multiple ip from same network on one interface

RouterOS General
1

Lets assume an example.
i have subnet 99.99.99.128/25
i should nat a lot of users so i should add some of this ip addresses to my eth2 and i can use just 99.99.99.205-99.99.99.215
i added 99.99.99.205/25 to eth2
i added 99.99.99.206/25 to eth2
..
..
i added 99.99.99.215/25 to eth2

everything was good but after the upgrade from 2.9.27 to 3.11 the ip addresses of eth2 randomly can not ping internet nor the gateway ( here 99.99.99.129 )

after a reboot the ip addresses that can ping and ipp addresses that cannot ping swap randomly.

i know that putting multiple ip from same network on one interface is not ok but before the upgrade everything worked fine but now just about 4 or 5 ip addresses can have internet at the same time until next reboot or next change in my configs. :open_mouth: :open_mouth:

2

do you really need to add every address to this interface?.. so try to add them with /32 mask, not /25

3

ok . so how they can see their gateway 99.99.99.129/25 ? with routing ? doesn’t make problem for other things ?
thanks for reply

4

Hi omidkosari,

Your setup info is limited. Are your users (or do you want your users) connected to this box with these IP addresses? And they want to get out to the internet? If so, assign only one IP to ether2. I use 192.168.0.1/24. Then setup a dhcp server on that interface for your users.

ADD: And multiple IPs on a single interface IS ok. :smiley:
But maybe not for this…

5

you should be able to add multiple ip address from one network to the SAME interface without any problems.
if you add multiple ip addresses from SAME network to DIFERENT interfaces you will face networking problems.