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Router refusing seemingly random IP's issue
Posted: Mon Apr 14, 2014 4:14 pm
by bosnet
Hi. I am the admin of a building network with multiple users, each having to go through a router. As far as I can tell, the router is refusing certain IP addresses. This seems to result in two errors. If I ping the router, for some people it will say "Destination Net Unreachable", in which case I simply reset the user's IP and then it works, but for some people it says "General Transmit Failure" which is only solved (sometimes) when I reset the router. I assume that both of these are cause by some problem with the router. Also, both of these problems are relatively new. It was working fine a few months ago.
I am fairly inexperienced with this, and I did not install and set up the network or the router, as I inherited the responsibility from someone else, so any assistance would be much appreciated.
Re: Router refusing seemingly random IP's issue
Posted: Mon Apr 14, 2014 4:45 pm
by SurferTim
Just out of curiosity, is your client router being issued an ip/subnet by the dhcp server that already exists on the dhcp client router?
Re: Router refusing seemingly random IP's issue
Posted: Mon Apr 14, 2014 5:17 pm
by catalin
could you please give us more details about the network , how the clinet computers are conected tho the router (switches , other devices) ?
Re: Router refusing seemingly random IP's issue
Posted: Mon Apr 14, 2014 7:44 pm
by bosnet
I have no idea. How would I determine that?
Re: Router refusing seemingly random IP's issue
Posted: Tue Apr 15, 2014 11:49 am
by bosnet
could you please give us more details about the network , how the clinet computers are conected tho the router (switches , other devices) ?
There are approximately 160 clients, and there are 8 switches. 20 clients connect to a switch, and then each of those 8 switches connect to another switch, to which the router and a server are connected. As far as I understand the purpose of the router is to assign everyone their IP addresses.
Re: Router refusing seemingly random IP's issue
Posted: Tue Apr 15, 2014 1:33 pm
by SurferTim
Post "/ip address" and the ip offers that the router is refusing from the dhcp server.
Re: Router refusing seemingly random IP's issue
Posted: Tue Apr 15, 2014 1:40 pm
by catalin
only users from certain building (connected to a individual switch ) are affected ? or all users , I suspect that one of your switch is not working properly .
Re: Router refusing seemingly random IP's issue
Posted: Tue Apr 15, 2014 9:08 pm
by bosnet
only users from certain building (connected to a individual switch ) are affected ? or all users , I suspect that one of your switch is not working properly .
I haven't checked if it's only users from one switch, but I doubt a switch is the problem since resetting the router sometimes solves the issue.
Post "/ip address" and the ip offers that the router is refusing from the dhcp server.
I'm afraid I don't quite understand what you are telling me to do.
Re: Router refusing seemingly random IP's issue
Posted: Wed Apr 16, 2014 1:11 am
by SurferTim
You stated that the router was refusing ip addresses from the dhcp server. What ip addresses is it refusing? If the dhcp server is attempting to issue a 192.168.0.x/24 ip, and you have a 192.168.0.x/24 localnet on the router, that could cause a problem.
The usual thing I recommend is enable verbose logging on the router. That should tell you what ip is being offered, and possibly why it is being refused.
/system logging
add topics=dhcp,debug action=memory