Device comes up, authenticator sends a EAP request (who are you)
Supplicant will reply with credentials (if supplicant software is installed)
Authenticator will send credentials to authenticaton server using RADIUS, however it can encrypt this using PEAP which in turn uses TLS with an access-request
Remember TLS implies digital certificates are required
authentication server will reply with an access-challenge
note that also as part of this process the server will go
through negotiations with the supplicant for which eap
protocol to use and also if configured and using tls
certificates will be exchanged to authenticate the server
chaining
if you want to authenticate a user and a device separately this is called chaining
if you want to perform chaining the EAP protocol you will need is EAP-Fast
modes
single-host
one device, one mac address only on this port
multi-host
one mac address authenticates and then any other mac address can use that port also as long as port stays up
multi-doman (MDA)
One each mode, allows one mac address for data and one mac address for voice
multi-auth
each device needs to authenticate individually, each mac address will need its own supplicant to authenticate
MAB
Mac address bypass, if no supplicant is installed, after a set
time the 802.1x will timeout and move to next method, if Mac
address is set in ISE then will authenticate with MAC address
configuring
on switch (authenticator)
aaa authentication dot1x default group radius
dot1x system-auth-control
int# authentication host-mode [multi-auth]
int# authentication [open/
open- for testing, allows all even if failed
int# dot1x pae authenticator
tells port that it is the authenticator
int# authentcation port-control-auto
tells port to allow dot1x to control access
to verify its working before leaving open mode use
int# show authentication int g0/1 or int# show
authentication sessions int g0/1
radius server attribute 6 on-for-login-auth
if using MAB, sends mac address to ISE
INT# MAB
ALLOWS MAB
int# authentication order dot1x mab
Methods
802.1X
Periodic re-authentication (disabled by default)
MAB
No periodic re-authenticaion
uses RADIUS service type 6
how methods are chosen
int# authentication order dot1x mab webauth
dot1x is chosen first, if timesout goes to mab then to webauth
int# authentication priority dot1x mab webauth
first choice is dictated by order, but if switch receives a dot1x request it will switch to dot1x
authentication event fail action next-method/ authorize vlan x
next method goes to next method, should only
be used if webauth configured or cycles
endlessly, authorize vlan x puts port into vlan x
authentication fallback command needed to enable webauth