02-02-2018 09:24 AM
I am having an issue getting a XE switch with CPL to authenticate existing connection when I apply the configuration template to the interfaces. This is normal. On non-CPL switches I simply do a "clear auth session" followed by a "clear mac address-table dynamic". When the MAC address table is repopulated the authentication process is run. This doesn't happen on CPL. If I do a "clear access-session" followed by "clear mac address-table dynamic", there are no authentication sessions showing up even though I see the MAC addresses show back up in the MAC address table. If I bounce the port the authentications work just fine.
I haven't determined if maybe there is a bug with the "clear mac address-table dynamic" not actually clearing out the MAC address table.
If there a different way I should be starting sessions over on XE CPL switches?
Solved! Go to Solution.
02-05-2018 02:14 PM
Hi Paul,
I tested this in my lab and what I notice is that this appears to be a bug in the new style. Since the MAC address is programmed statically, the 'clear mac address-table' command has no impact, the difference I see between legacy and new-style is that when I issue a 'clear authentication session' command the static mac address is cleared too, while with 'clear access-session' this doesn't happen. Without a "session start" (IOS detecting a new mac address on the port), there won't be new auth session context built around it, port bounce makes the switch relearn the mac address, hence a workaround. Will raise a bug and follow up with our developers. Hope this helps..
Cheers,
~Hari
c3850-switch#show auth sessions interface Gi 1/0/3 | inc Address|---|Auth
Interface MAC Address Method Domain Status Fg Session ID
----------------------------------------------------------------------
Gi1/0/3 1c17.d341.d0ce mab VOICE Auth AC14FE0100000FAD0024EEEC
c3850-switch#
c3850-switch#show mac address-table interface gigabitEthernet 1/0/3
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
101 1c17.d341.d0ce STATIC Gi1/0/3
Total Mac Addresses for this criterion: 1
c3850-switch#clear authentication sessions interface gigabitEthernet 1/0/3
c3850-switch#show mac address-table interface gigabitEthernet 1/0/3
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
c3850-switch#
02-05-2018 11:11 AM
Hi Paul,
Could you share the interface and policy-map configurations?
~Hari
02-05-2018 11:15 AM
Here you go. This is the template we are using. I am not worried about the template as I and other ISE engineers here have used it on ISE installs. I am just asking how to properly clear authentication sessions and get them to restart. As I said on the original post a “clear auth session” and “clear mac address-table dynamic” always works on non-CPL switches.
aaa group server radius ISE-RADIUS
server name
!
!**CPL**
!
ip access-list extended PERMIT-ANY
permit ip any any
!
service-template CRITICAL
description Apply When none of the RADIUS servers are reachable
access-group PERMIT-ANY
!
class-map type control subscriber match-any AAA-DOWN
match result-type aaa-timeout
!
class-map type control subscriber match-all DOT1X-FAILED
match method dot1x
match result-type method dot1x authoritative
!
policy-map type control subscriber DOT1X-DEFAULT
event session-started match-all
10 class always do-all
10 authenticate using dot1x priority 10
20 authenticate using mab priority 20
event violation match-all
10 class always do-all
10 restrict
event agent-found match-all
10 class always do-all
10 terminate mab
20 authenticate using dot1x priority 10
event authentication-failure match-first
10 class AAA-DOWN do-all
10 authorize
20 activate service-template CRITICAL
30 terminate dot1x
40 terminate mab
50 pause reauthentication
20 class DOT1X-FAILED do-all
10 terminate dot1x
20 authenticate using mab priority 20
event aaa-available match-all
10 class always do-all
10 clear-session
!
!**PORT CONFIG**
!
interface GigabitEthernet1/0/10
description ISE-802.1x
switchport mode access
authentication periodic
authentication timer reauthenticate server
access-session control-direction in
access-session port-control auto
no access-session closed
mab
dot1x pae authenticator
dot1x timeout tx-period 7
service-policy type control subscriber DOT1X-DEFAULT
!
02-05-2018 02:14 PM
Hi Paul,
I tested this in my lab and what I notice is that this appears to be a bug in the new style. Since the MAC address is programmed statically, the 'clear mac address-table' command has no impact, the difference I see between legacy and new-style is that when I issue a 'clear authentication session' command the static mac address is cleared too, while with 'clear access-session' this doesn't happen. Without a "session start" (IOS detecting a new mac address on the port), there won't be new auth session context built around it, port bounce makes the switch relearn the mac address, hence a workaround. Will raise a bug and follow up with our developers. Hope this helps..
Cheers,
~Hari
c3850-switch#show auth sessions interface Gi 1/0/3 | inc Address|---|Auth
Interface MAC Address Method Domain Status Fg Session ID
----------------------------------------------------------------------
Gi1/0/3 1c17.d341.d0ce mab VOICE Auth AC14FE0100000FAD0024EEEC
c3850-switch#
c3850-switch#show mac address-table interface gigabitEthernet 1/0/3
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
101 1c17.d341.d0ce STATIC Gi1/0/3
Total Mac Addresses for this criterion: 1
c3850-switch#clear authentication sessions interface gigabitEthernet 1/0/3
c3850-switch#show mac address-table interface gigabitEthernet 1/0/3
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
c3850-switch#
02-05-2018 02:27 PM
Yeah I sort of figured that was what was happening. Obviously, doing a port bounce is not an option if we are trying to unobtrusively put the switch into Monitor mode.
Thanks for checking on this.
Paul Haferman
Office- 920.996.3011
Cell- 920.284.9250
02-06-2018 05:40 AM
One question I have is when you initially deploy the template to the interface the MAC address entry is not static. Shouldn’t the MAC address get authenticated or a “clear mac address-table dynamic” work? I am seeing this issue even on the initial application of the template. I have to bounce the port to get authentications to show up. The 802.1x once will work right away because they are responding to the EAPol, but MAB ones aren’t showing up without a port bounce.
Paul Haferman
Office- 920.996.3011
Cell- 920.284.9250
02-06-2018 07:45 AM
In my tests I can trigger a reauthentication after applying a different template by issuing the command “clear authentication session”
George
Warning: I either dictated this to my device, or typed it with my thumbs. Erroneous words are a feature, not a typo.
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