Nexus 5000 cant access radius

Question

hello,
before two weeks ago we installed radius server in our network.
the other switches in the network are work fine with the radius,
the nexus 5k can reach the server with ping, but cant authenticate the users, only local users can access.
test aaa server radius is also failed with "error authnticating to server.
please take a look in the configuration below.
thanks!
here is the configureation :
logging level radius 5
radius-server retransmit 3
radius-server host 192.168.x.y key 7 "xxxxxxxx" authentication accounting
aaa group server radius myradius
aaa authentication login default group myradius local
nexus5000k# show radius-server groups
total number of groups:2
following RADIUS server groups are configured:
        group radius:
                    server:  all configured radius servers
                    deadtime is 0
        group myradius:
                   server: 192.168.x.y on auth-port 1812, acct-port 1813
                   deadtime is 0

Answer 1

You can specify that a RADIUS server is to be used only for accounting purposes or only for authentication purposes. By default, RADIUS servers are used for both accounting and authentication. You can also specify the destination UDP port numbers where RADIUS accounting and authentication messages should be sent.
To configure the accounting and authentication attributes for RADIUS servers, perform this task:
www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/configuration/guide/cli/CLIConfigurationGuide/sec_radius.html#wp1298572