Hi there, I have a problem that is really annoying. All my RB433 with ROS v 4.16 are acting the same way. Its working fine and suddenly the IP stops responding and I have to access it by MAC. Then when I try to ping from it to my other routers or any valid IP I get "net prohibited" error message. Then I have to change the IP of the interface to make it work again. After some time the same behavior repeats itself. What can be the cause of this and what solution do you guys advise me to use? I tought that maybe some ppl was using the same IP on the network to try to use free internet, but only the ROS v 4.16 does that!!!


Any help will be welcomed

Cya!!!

Any solution to this problem? I cant figure out what is the cause of this problem!!!

Come on guys.... any suggestion so I can fix this? I tried to upgrade to version 4.17 stable... guess what.... same problem! This is complete nonsense. It just stop working on the IP its using and I have to change the IP so it can work nice again for some time!!!!!

Really? No one ever had this problem? No one knows nothing about this? And for sure no one is willing to help!!!!!! At least if no one knows nothing, say so. This problem is really annoying and since Im using RADIUS, when it happens my users cant auth... What can it possibly be?????????????? Im trying what I can here but the result is always the same. What is the meanning of NET PROHIBITED????? How can I get a solution if I dont even know what can possibly cause this error message? It stops working without explanation, so PLS, REALLY, ANY advice on the direction I should go to solve this problem would be really welcomed!!!

It's ICMP type 3, code 9, described in section 3.2.2.1 in http://www.ietf.org/rfc/rfc1122.txt.
I'm having no such issues on my RB433 I use at home.

At least if no one knows nothing, say so.

That's ridiculous. I get that you're desperately looking for help, but there are thousands of users on this forum. You cannot expect all of them to drop you a line here saying "hey, just to let you know: no idea how to fix your problem". If no one posts, no one knows.

Have you contacted the official support channel at support@mikrotik.com?

You have to agree with me, I got some attention with that last reply of mine... Well, now I can dig up some solution based on your reply! Thx dude and I was really desperate!!!

Little late but maybe my post will help others.
I have same issue after I created a new hotspot server and trying to add a second routerboard wifi connected to the main hotspot.
I solved this problem creating a firewall rule to accept connections on vlan interface of hotspot's server on input chain.
It looks like the rules automatically created on hotspot server blocks communication with second device.

Hello,
Similar to this issue. Just want to share mine.

I set up the CHR virtual machine (guest) running in a virtual box. I used my computer as a host virtual machine.
My computer and CHR with a bridge interface connected the internet via my MikroTik router (RB951G-2HnD). This denotes both got IP addresses from the router.
I have just seen error messages "net prohibited" when I use a PING command as depicted in the figure. I have been searching for the solution to see what happens and to get rid of the messages.
I found this post. I realized that both CHR virtual machine and my computer connected the router with a hotspot server. I tried to bypass the CHR mac adddress/ip address using the IP Binding feature of the hotspot server. It works!!!! I got the ping response without those "net prohibited" messages.

In this post. I also have the similar idea with @ovidiu that the hotspot server could block the communication. This would help other people who run into this problem.