The following example describes FA configuration and behavior in a dual-homed SMLT deployment.
The following figure shows a simple FA solution in a dual-homed SMLT deployment. In this deployment, a pair of BEB switches (BEB A and BEB B) operating as IST peers are configured as the FA Server. An access switch or a wiring closet switch configured as an FA Proxy connects to the FA Server. The FA Proxy advertises I-SID-to-VLAN assignment mappings to the FA Server. Both BEB switches receive the mapping information using LLDP PDUs containing assignment TLVs. The switch that learns the mapping first considers the I-SID to be discovered locally and creates the I-SID on its device. The mapping information is then shared with its IST peer switch. When the peer switch receives the mapping across IST in a new SMLT message, it too creates the I-SID on its device. This I-SID however, is considered to be discovered remotely because it is learnt from synchronization with the peer switch. The mappings can also be learned on the FA Server from both LLDP PDUs and from IST synchronization.
Ensure that the proxy device (for example, an access switch) is properly configured for FA. See the corresponding product documentation for information on how to configure FA on the switch.
Caution
For the IST peer switches acting as the FA Server to transmit the same FA System ID (based on the virtual MAC), SMLT configuration on both the switches must be the same.
For detailed information on configuring SMLT and vIST, see MultiLink Trunking and Split MultiLink Trunking.
Configure BEB A and BEB B as the FA Server
Perform the following configuration on each switch.
fa enable
Note
Enabling FA automatically enables message authentication. Also, the authentication key is set to the default value and the system displays the encrypted authentication key on the output.
fa authentication-key [WORD<0-32>]
Caution
When you configure the FA authentication key, you must configure the same value on both BEB switches in the SMLT.
Verify global and MLT-level FA configuration on BEB A and BEB B:
Verify FA discovery on BEB A and BEB B:
View FA I-SID-to-VLAN assignments on BEB A and BEB B:
Verify creation of Switched UNI I-SIDs on BEB A and BEB B:
View ELAN I-SID information using show i-sid elan.
View ELAN I-SID information on a specific MLT using show mlt i-sid [<1–512>].
Note
Viewing ELAN I-SID information on an MLT is very useful to understand the origin of the I-SID, when multiple client or proxy devices connecting to the FA Server using SMLT MLT advertise the same I-SID-to-VLAN mappings. In the event of a link failure on an MLT, the origin of the I-SID helps determine on which MLT, and thereby from which proxy or client device, the mappings were successfully learnt.
SMLT configuration on BEB A and BEB B:
On BEB A:
Switch:1>en Switch:1#conf t Enter configuration commands, one per line. End with CNTL/Z. Switch:1(config)#interface mlt 1 Switch:1(config)#smlt
On BEB B:
Switch:2>en Switch:2#conf t Enter configuration commands, one per line. End with CNTL/Z. Switch:2(config)#interface mlt 1 Switch:2(config)#smlt
vIST configuration on BEB A and BEB B:
On BEB A:
Switch:1(config)#vlan create 2261 type port-mstprstp 0 Switch:1(config)#vlan i-sid 2261 1502261 Switch:1(config)#interface vlan 2261 Switch:1(config)#ip address 192.0.2.0 255.255.255.0 2
Configure BEB B (IP address 192.0.2.1) as the IST peer.
Switch:1(config)#virtual-ist peer-ip 192.0.2.1 vlan 2261 Switch:1(config)#show virtual-ist Switch:1(config)#exit
On BEB B:
Switch:2(config)#vlan create 2261 type port-mstprstp 0 Switch:2(config)#vlan i-sid 2261 1502261 Switch:2(config)#interface vlan 2261 Switch:2(config)#ip address 192.0.2.1 255.255.255.0 2
Configure BEB A (IP address 192.0.2.1) as the IST peer.
Switch:2(config)#virtual-ist peer-ip 192.0.2.1 vlan 2261 Switch:2(config)#show virtual-ist Switch:2(config)#exit
FA configuration on BEB A:
Enable FA globally and on the MLT:
Switch:1(config)#fa enable
Switch:1>show fa
================================================================================
Fabric Attach Configuration
================================================================================
FA Service : enabled
FA Element Type : server
FA Assignment Timeout : 240
FA Discovery Timeout : 240
FA Provision Mode : spbm
Optionally, configure an FA authentication key with the value dual-homed-smlt. Ensure that you configure the same value on both switches BEB A and BEB B.
Switch:1(config)#interface mlt 1 Switch:1(config-mlt)#fa authentication-key dual-homed-smlt
Enable FA on the MLT:
Switch:1(config-mlt)#fa enable
Switch:1(config-mlt)#exit
Switch:1(config)#show fa interface
====================================================================
Fabric Attach Interfaces
====================================================================
INTERFACE SERVER MGMT MGMT MSG AUTH MSG AUTH ORIGIN
STATUS ISID CVID STATUS KEY
--------------------------------------------------------------------
Mlt1 enabled 0 0 enabled ****
--------------------------------------------------------------------
1 out of 1 Total Num of fabric attach interfaces displayed
--------------------------------------------------------------------
Verify discovery of the FA Proxy:
Switch:1(config)#show fa elements
================================================================================
Fabric Attach Discovery Elements
================================================================================
MGMT ELEM ASGN
PORT TYPE VLAN STATE SYSTEM ID AUTH AUTH
--------------------------------------------------------------------------------
3/21 proxy 2 T / S 10:cd:ae:09:40:00:20:00:00:01 AP AP
3/22 proxy 2 T / S 10:cd:ae:09:40:00:20:00:00:01 AP AP
3/23 proxy 2 T / S 10:cd:ae:09:40:00:20:00:00:01 AP AP
================================================================================
Fabric Attach Authentication Detail
================================================================================
ELEM OPER ASGN OPER
PORT AUTH STATUS AUTH STATUS
--------------------------------------------------------------------------------
3/21 successAuth successAuth
3/22 successAuth successAuth
3/23 successAuth successAuth
State Legend: (Tagging/AutoConfig)
T= Tagged, U= Untagged, D= Disabled, S= Spbm, V= Vlan, I= Invalid
Auth Legend:
AP= Authentication Pass, AF= Authentication Fail,
NA= Not Authenticated, N= None
--------------------------------------------------------------------------------
3 out of 3 Total Num of fabric attach discovery elements displayed
The FA Proxy advertises I-SID-to-VLAN assignment mappings to BEB A, on MLT ports 3/21 to 3/23. View the FA I-SID-to-VLAN assignments on BEB-A:
All ports in the MLT receive the FA assignment mappings, as shown in the following output.
Switch:1(config)#show fa assignment
===================================================
Fabric Attach Assignment Map
==================================================
Interface I-SID Vlan State Origin
---------------------------------------------------
3/21 2 2 active proxy
3/21 3 3 active proxy
3/21 4 4 active proxy
3/22 2 2 active proxy
3/22 3 3 active proxy
3/22 4 4 active proxy
3/23 2 2 active proxy
3/23 3 3 active proxy
3/23 4 4 active proxy
FA configuration on BEB B:
Enable FA globally and on the MLT:
Switch:2(config)#fa enable
Switch:2(config)#show fa
========================================================================
Fabric Attach Configuration
========================================================================
FA Service : enabled
FA Element Type : server
FA Assignment Timeout : 240
FA Discovery Timeout : 240
FA Provision Mode : spbm
Configure the FA authentication key dual-homed-smlt. Ensure that you configure the same value as on BEB A.
Switch:2(config)#interface mlt 1 Switch:2(config-mlt)#fa authentication-key dual-homed-smlt
Enable FA on the MLT:
Switch:2(config-mlt)#fa enable
Switch:2(config-mlt)#exit
Switch:2(config)#show fa interface
====================================================================
Fabric Attach Interfaces
====================================================================
INTERFACE SERVER MGMT MGMT MSG AUTH MSG AUTH ORIGIN
STATUS ISID CVID STATUS KEY
--------------------------------------------------------------------
Mlt1 enabled 0 0 enabled ****
--------------------------------------------------------------------
1 out of 1 Total Num of fabric attach interfaces displayed
--------------------------------------------------------------------
Verify discovery of FA Proxy:
Switch:2(config)#show fa elements
================================================================================
Fabric Attach Discovery Elements
================================================================================
MGMT ELEM ASGN
PORT TYPE VLAN STATE SYSTEM ID AUTH AUTH
--------------------------------------------------------------------------------
3/17 proxy 2 T / S 10:cd:ae:09:40:00:20:00:00:01 AP AP
3/18 proxy 2 T / S 10:cd:ae:09:40:00:20:00:00:01 AP AP
3/19 proxy 2 T / S 10:cd:ae:09:40:00:20:00:00:01 AP AP
3/20 proxy 2 T / S 10:cd:ae:09:40:00:20:00:00:01 AP AP
================================================================================
Fabric Attach Authentication Detail
================================================================================
ELEM OPER ASGN OPER
PORT AUTH STATUS AUTH STATUS
--------------------------------------------------------------------------------
3/17 successAuth successAuth
3/18 successAuth successAuth
3/19 successAuth successAuth
3/20 successAuth successAuth
State Legend: (Tagging/AutoConfig)
T= Tagged, U= Untagged, D= Disabled, S= Spbm, V= Vlan, I= Invalid
Auth Legend:
AP= Authentication Pass, AF= Authentication Fail,
NA= Not Authenticated, N= None
--------------------------------------------------------------------------------
4 out of 4 Total Num of fabric attach discovery elements displayed
The FA Proxy device advertises I-SID-to-VLAN assignment mapping requests to BEB B on MLT ports 3/17 to 3/20.
View FA I-SID-to-VLAN assignments on BEB-B:
Switch:2(config)#show fa assignment 3/17
===================================================
Fabric Attach Assignment Map
==================================================
Interface I-SID Vlan State Origin
---------------------------------------------------
3/17 2 2 active proxy
3/17 3 3 active proxy
3/17 4 4 active proxy
Verify creation of FA Switched UNI (ELAN) I-SIDs on BEB A and BEB B:
Verify the creation of FA Switched UNI (ELAN) I-SIDs on BEB A and BEB B.
On BEB A:
Switch:1(config)#show i-sid elan
===================================================================================
Isid Info
===================================================================================
ISID ISID PORT MLT ORIGIN ISID
ID TYPE VLANID INTERFACES INTERFACES NAME
-----------------------------------------------------------------------------------
2 ELAN N/A - c2:1 - --- - -lr - ISID-2
3 ELAN N/A - c3:1 - --- - -lr - ISID-3
4 ELAN N/A - c4:1 - --- - -lr - ISID-4
ORIGIN Legend:
C: manually configured; D: discovered by FA or EPT
M: FA management; E: discovered by EAP; A: auto-sense
l: discover by local switch r: discover by remote VIST switch
8k_fanout:1(config-if)#shlw mlt i-sid
View the I-SID information for MLT 1 on BEB A.
Switch:1(config)#show mlt i-sid 1
================================================================================
MLT Isid Info
================================================================================
ISID ISID
MLTID IFINDEX ID VLANID C-VID TYPE ORIGIN ISID BPDU
NAME
--------------------------------------------------------------------------------
1 6144 2 N/A 2 ELAN - --- - -lr - ISID-2
1 6144 3 N/A 3 ELAN - --- - -lr - ISID-3
1 6144 4 N/A 4 ELAN - --- - -lr - ISID-4
--------------------------------------------------------------------------------
3 out of 3 Total Num of i-sid endpoints displayed
ORIGIN Legend:
C: manually configured; D: discovered by FA or EPT
M: FA management; E: discovered by EAP; A: auto-sense
l: discover by local switch r: discover by remote VIST switch
8k_fanout:1(config-if)#shlw mlt i-sid
On BEB B:
Switch:2(config)#show i-sid elan
===================================================================================
Isid Info
===================================================================================
ISID ISID PORT MLT ORIGIN ISID
ID TYPE VLANID INTERFACES INTERFACES NAME
------------------------------------------------------------------------------------
2 ELAN N/A - c2:1 - --- - -lr - ISID-2
3 ELAN N/A - c3:1 - --- - -lr - ISID-3
4 ELAN N/A - c4:1 - --- - -lr - ISID-4
ORIGIN Legend:
C: manually configured; D: discovered by FA or EPT
M: FA management; E: discovered by EAP; A: auto-sense
l: discover by local switch r: discover by remote VIST switch
8k_fanout:1(config-if)#shlw mlt i-sid
View the I-SID information for MLT 1 on BEB B.
Switch:1(config)#show mlt i-sid 1
================================================================================
MLT Isid Info
================================================================================
ISID ISID
MLTID IFINDEX ID VLANID C-VID TYPE ORIGIN ISID BPDU
NAME
--------------------------------------------------------------------------------
1 6144 2 N/A 2 ELAN - --- - -lr - ISID-2
1 6144 3 N/A 3 ELAN - --- - -lr - ISID-3
1 6144 4 N/A 4 ELAN - --- - -lr - ISID-4
--------------------------------------------------------------------------------
3 out of 3 Total Num of i-sid endpoints displayed
ORIGIN Legend:
C: manually configured; D: discovered by FA or EPT
M: FA management; E: discovered by EAP; A: auto-sense
l: discover by local switch r: discover by remote VIST switch
8k_fanout:1(config-if)#shlw mlt i-sid
The following section describes the behavior if, for example, a link failure occurs between the FA Proxy and BEB B, as shown in the following figure.
View the I-SID-to-VLAN assignments on BEB A:
Switch:1(config)#show fa assignment 3/21
===================================================
Fabric Attach Assignment Map
==================================================
Interface I-SID Vlan State Origin
---------------------------------------------------
3/21 2 2 active proxy
3/21 3 3 active proxy
3/21 4 4 active proxy
View the Switched UNI (ELAN) I-SIDs created on BEB A.
Switch:1(config)#show i-sid elan
======================================================================================
Isid Info
======================================================================================
ISID ISID PORT MLT ORIGIN ISID
ID TYPE VLANID INTERFACES INTERFACES NAME
-------------------------------------------------------------------------------------
2 ELAN N/A - c2:1 - --- - -l- - ISID-2
3 ELAN N/A - c3:1 - --- - -l- - ISID-3
4 ELAN N/A - c4:1 - --- - -l- - ISID-4
ORIGIN Legend:
C: manually configured; D: discovered by FA or EPT
M: FA management; E: discovered by EAP; A: auto-sense
l: discover by local switch r: discover by remote VIST switch
8k_fanout:1(config-if)#shlw mlt i-sid
View the I-SID information for MLT 1 on BEB A.
Switch:1(config)#show mlt i-sid 1
================================================================================
MLT Isid Info
================================================================================
ISID ISID
MLTID IFINDEX ID VLANID C-VID TYPE ORIGIN ISID BPDU
NAME
--------------------------------------------------------------------------------
1 6144 2 N/A 2 ELAN - --- - -l- - ISID-2
1 6144 3 N/A 3 ELAN - --- - -l- - ISID-3
1 6144 4 N/A 4 ELAN - --- - -l- - ISID-4
--------------------------------------------------------------------------------
3 out of 3 Total Num of i-sid endpoints displayed
ORIGIN Legend:
C: manually configured; D: discovered by FA or EPT
M: FA management; E: discovered by EAP; A: auto-sense
l: discover by local switch r: discover by remote VIST switch
8k_fanout:1(config-if)#shlw mlt i-sid
View the Switched UNI (ELAN) I-SIDs created on BEB B.
BEB-B:1(config-mlt)#show i-sid elan
======================================================================================
Isid Info
======================================================================================
ISID ISID PORT MLT ORIGIN ISID
ID TYPE VLANID INTERFACES INTERFACES NAME
--------------------------------------------------------------------------------------
2 ELAN N/A - c2:1 - --- - --r - ISID-2
3 ELAN N/A - c3:1 - --- - --r - ISID-3
4 ELAN N/A - c4:1 - --- - --r - ISID-4
ORIGIN Legend:
C: manually configured; D: discovered by FA or EPT
M: FA management; E: discovered by EAP; A: auto-sense
l: discover by local switch r: discover by remote VIST switch
8k_fanout:1(config-if)#shlw mlt i-sid
View the I-SID information for MLT 1 on BEB B.
Switch:1(config)#show mlt i-sid 1
================================================================================
MLT Isid Info
================================================================================
ISID ISID
MLTID IFINDEX ID VLANID C-VID TYPE ORIGIN ISID BPDU
NAME
--------------------------------------------------------------------------------
1 6144 2 N/A 2 ELAN - --- - --r - ISID-2
1 6144 3 N/A 3 ELAN - --- - --r - ISID-3
1 6144 4 N/A 4 ELAN - --- - --r - ISID-4
--------------------------------------------------------------------------------
3 out of 3 Total Num of i-sid endpoints displayed
ORIGIN Legend:
C: manually configured; D: discovered by FA or EPT
M: FA management; E: discovered by EAP; A: auto-sense
l: discover by local switch r: discover by remote VIST switch
8k_fanout:1(config-if)#shlw mlt i-sid