hello everybody. I installed several rb751 and CCR 1016. all of them are connected to a switch. when they are plugged all together i can't access from winbox using the IP address, i can only access using the mac address. when i unplug the Router and plug it directly to my pc i can access to it using its IP Address.

help please

What kind of switch do you have? a cheap one? (kinda home switch) How much traffic passing through?

Noo its an high end HP switch.

To access via IP the ip/netmasks on the routerboards & PC need to be in the same subnet.

of course and they are on the same subnet

Sounds like the switch is not behaving as a straight layer 2 switch then - does it have layer 3 capabilities?

it is not issue of the switch because some routers works but the large majority does not. moreover the switch is a layer 3 switch.

Each router may have different IP settings and different IP Firewall filter settings so some working and some not does not really rule out that the switch is involved. A layer 3 switch is capable of making switching decisions based on the IP header so depending on settings it could certainly cause problems for IP traffic. Try using ping and trace route to see what is actually happening to IP traffic on the path.

thanks for you reply. but there is not a single firewall rule configured on all of them. I am using them to extend my network to a wireless network. so i am making a bridge between the wireless interface and the ethernet interface.

Very basic question, but does each router have a different IP address assigned to it?

yess of course each router has its unique IP address :S. when all of them are connected together i face this problem. when i plug to it directly from my pc it works fine

Perhaps you can upload an example config. Have you tried a basic layer 2 switch in place of the HP switch?