unsolicited incoming arp

[chpmotry]

hi guys .

I have a network that consists of a number of access layer switches and a core switch that is connected to a firewall via a wireless link. And the clients are supposed to connect to a web server behind this firewall. The network worked without problems for years until two weeks ago this error was displayed on random clients. The antivirus installed on the clients detected the presence of a Mac spoofing on the network and immediately disconnected the client from the network. However, the clients get the core switch IP, default gateway and DNS from DHCP. I will send you the topology of my network and error image. How do you think I can fix the problem?

[Richard Burts]

I have looked at the diagram and it seems fairly straightforward. And according to your post it worked well until recently. Your description of the issue was "The antivirus installed on the clients detected the presence of a Mac spoofing on the network". So the problem is not about routing or network setup but is about security policy. So you, or someone with responsibility for network security need to investigate and find if something is really spoofing on the network.

[MHM Cisco World]

it seem to me l2 loop

you can check that by see root in all SW is it point to same SW or not

MHM

[liviu.gheorghe · Accepted solution]

Was the antivirus installed on the clients just around when the problem started to appear? If this is the case, then you probably had this issue for some time and only noticed recently with the help of the antivirus software.