Virtual interswitch trunk (vIST)

Use this procedure to create a virtual IST (vIST).

vIST creates a virtualized channel through the SPBM cloud, and this channel connects two SMLT devices to form a virtualized Switch Cluster. Note that the SPBM cloud can consist of as few as two nodes.

Important

• When you create a vIST, VLANs assigned to SMLT ports must have an I-SID assigned.

• If you assign a VLAN to an I-SID on one SMLT-BEB node, then you must create the same VLAN and assign it to the same I-SID on the peer SMLT-BEB node even if no devices are connected to this second node.

• The vIST VLAN must also be associated with an I-SID. You can use the same vIST VLAN in another part of your network, but the I-SID associated with the vIST VLAN must not be used anywhere else.

Note

Simplified Virtual-IST (vIST) is for non-SPB customers who use SMLT with legacy IST. Simplified VIST is available for legacy multicast deployments only when the boot flag (spbm-config-mode) is disabled.

For more information, see Configuring Simplified vIST in SMLT topologies .

About this task

The following list provides an overview of the configuration steps:

• Enable SPBM and IS-IS globally.

• Configure SPBM and IS-IS.

• Configure an L2 VSN by assigning an I-SID to the C-VLAN, which is used by the vIST.

For information about SPBM and IS-IS, see SPBM and IS-IS Infrastructure Fundamentals.

Important

Do not change the system MTU to less than the default value of 1950 bytes. The system MTU must be 1950 or jumbo because of the header size increase when transmitting packets over the SPBM cloud.

1. Enter Global Configuration mode:

   enable

   configure terminal

2. Create a vIST:

   virtual-ist peer-ip <A.B.C.D> vlan <1-4059>

3. Verify your vIST configuration:

   show virtual-ist

Example

The configuration example contains annotations (in parenthesis) to explain the configuration information.

SMLT with vIST configuration example

Note

This configuration example is for vIST peer B.

#
# ISIS SPBM CONFIGURATION
#

router isis
spbm 1
spbm 1 nick-name 0.00.16
spbm 1 b-vid 10,20 primary 10
spbm 1 smlt-virtual-bmac 00:00:84:04:01:01
spbm 1 smlt-peer-system-id a051.c6eb.c865
exit

#
# MLT CONFIGURATION
#

mlt 1 enable
mlt 1 member 1/28

                    
mlt 2 enable
mlt 2 member 1/10
mlt 2 encapsulation dot1q

#
# VLAN CONFIGURATION
#

vlan members remove 1 1/28,1/10

(The rest of this VLAN section are all prerequisites for configuring a vIST.)
vlan create 10 type spbm-bvlan  (This command and the next create the B-VLANs.)
vlan create 20 type spbm-bvlan
vlan create 33 type port-mstprstp 0
vlan i-sid 33 33
mlt 1 vlan 33

vlan create 100 type port-mstprstp 0  (Creates the C-VLAN for the vIST VLAN.)
vlan i-sid 100 100  (Creates a Layer 2 VSN for the vIST VLAN.)
interface Vlan 100

ip address 192.0.2.2 255.255.255.0 0  (Assigns an IP to the vIST VLAN.)
exit

#
# VIRTUAL vIST CONFIGURATION
#

virtual-ist peer-ip 192.0.2.1 vlan 100  (vIST configuration.)

#
# MLT INTERFACE CONFIGURATION
#

interface mlt 1
smlt
exit 
               
interface mlt 2
isis
isis spbm 1
isis enable
exit

#
# PORT CONFIGURATION - PHASE II
#

interface GigabitEthernet 1/28
no shutdown
no spanning-tree mstp force-port-state enable
exit

interface GigabitEthernet 1/10
no shutdown
exit

#

# ISIS CONFIGURATION
#

router isis
is-type l1
manual-area 11.1111 
exit
router isis enable

If you need to change the virtual IST (vIST) peer-ip or vlan, use this procedure to delete the vIST first.

Note

• You must disable IS-IS globally before deleting a vIST, and then re-enable it after creating a new vIST.

• You do not have to set the SMLT peer system ID or the virtual B-MAC to 0 before you change the vIST peer IP address or VLAN ID number.

1. Enter Global Configuration mode:

   enable

   configure terminal

2. Disable IS-IS globally:

   no router isis enable

3. Delete the vIST:

   no virtual-ist peer-ip

4. Create a vIST:

   virtual-ist peer-ip <A.B.C.D> vlan <1-4059>

5. Enable IS-IS globally:

   router isis enable

This procedure shows how to configure Simplified vIST in an SMLT environment. It includes steps to configure the following:

• Setting the boot config flag

• Configuring the vIST peer

• Enabling Simplified vIST

Important

When you enable Simplified vIST with the virtual-ist enable command, two VLANs are automatically created to support vIST. The VLAN IDs are: 4086 and 4087.

About this task

Important

Do not change the system MTU to less than the default value of 1950 bytes. The system MTU must be 1950 or jumbo because of a header size increase.

1. Enter Global Configuration mode:

   enable

   configure terminal

2. Disable the boot flag:

   no boot config flags spbm-config-mode

   The system responds with these messages:

   Warning: Please save the configuration and reboot the switch for this to take effect.

   Warning: Please carefully save your configuration file before rebooting the switch. Saving configuration file when spbm-config-mode is changed to disable, removes SPBM configurations from the configuration file.

3. Save the configuration, and then reboot the switch.
   

   Important

   Any change to the spbm-config-mode boot flag requires a reboot for the change to take effect.

4. Create the vIST VLAN:

   vlan create <2-4059> type port-mstprstp <0–63>

   interface vlan <1-4059>

   ip address <A.B.C.D/X>

5. Configure the vIST peer address and VLAN:

   virtual-ist peer-ip <A.B.C.D> vlan <1-4059>

6. Configure the SMLT MLT:

   mlt <1-512> enable

   mlt <1-512> member {slot/port[/sub-port] [-slot/port[/sub-port]] [,...]}

   interface mlt <1-512>

   smlt

7. Configure the vIST MLT:

   mlt <1-512> enable

   mlt <1-512> member {slot/port[/sub-port] [-slot/port[/sub-port]] [,...]}

   mlt <1-512> encapsulation dot1q

   interface mlt <1-512>

   virtual-ist enable

   

   Note

   The virtual-ist enable command enables Simplified vIST and is only available when the spbm-config-mode boot flag is disabled.

8. Create a customer VLAN and assign the SMLT MLT ID:

   vlan create <2-4059>

   vlan mlt <1-4059> <1-512>

   interface vlan <1-4059>

   ip address <A.B.C.D/X>

Example

enable
configure terminal
no boot config flags spbm-config-mode

Save the configuration and reboot the switch.

virtual-ist peer-ip 192.0.2.1 vlan 50

mlt 3 enable
mlt 3 member 1/35,1/36
interface mlt 3
smlt
exit
mlt 5 enable
mlt 5 member 2/15,2/17
mlt 5 encapsulation dot1q
interface mlt 5
virtual-ist enable
exit
vlan create 50 type port-mstprstp 0
interface vlan 50
ip address 192.0.2.2 255.255.255.0 1
exit
vlan create 100
vlan mlt 100 3
interface vlan 100
ip address 198.51.100.1 255.255.255.0 2
exit