Configuring SPBM IPv4 Shortcuts

In addition to Layer 2 virtualization, the SPBM model is extended to also support Routed SPBM, otherwise called SPBM IP Shortcuts.

SPBM allows a network to make the best use of routing and forwarding techniques, where only the BEBs perform an IP route lookup and all other nodes perform standard Ethernet switching based on the existing shortest path tree. This allows for end to end IP-over-Ethernet forwarding without the need for ARP, flooding, or reverse learning.

To enable IP shortcuts on the BEBs, you can configure a circuitless IP (CLIP) address (loopback address), and specify this address as the IS-IS source address. This source address is automatically advertised into IS-IS using TLV 135. In addition, to advertise routes from the BEBs into the SPBM network, you must enable route redistribution of direct and static routes into IS-IS.

Note

The loopback address on each switch or BEB must all be in different subnets to ensure connectivity between them. To do this, use a 32-bit mask with the CLIP address.

Before you begin

You must configure the required SPBM and IS-IS infrastructure, which includes the creation of SPBM B-VLANs.
Before redistributing routes into IS-IS, you must create the Customer VLANs, add slots/ports, and add the IP addresses and network masks.

Procedure

Enter Loopback Interface Configuration mode

enable

configure terminal

interface Loopback <1-256>
Configure a CLIP interface to use as the source address for SPBM IP shortcuts:

ip address [<1-256>] <A.B.C.D/X>
Exit the Loopback Interface Configuration mode to Global Configuration mode:

exit
Log on to IS-IS Router Configuration mode:

router isis
Specify the CLIP interface as the source address for SPBM IP shortcuts:

ip-source-address <A.B.C.D>
Configure SPBM IP shortcuts:

spbm <1–100> ip enable
Display the status of SPBM IP shortcuts on the switch:

show isis spbm
Identify routes on the local switch to be announced into the SPBM network:

redistribute {bgp | direct | ospf | rip | static}
Enable routes to be announced into the SPBM network

redistribute {bgp | direct | ospf | rip | static} enable
If you want to delete the configuration, use the no option:

no redistribute {bgp | direct | ospf | rip | static}

no redistribute {bgp | direct | ospf | rip | static} enable
Exit to Global Configuration mode:

exit
Apply the configured redistribution:

isis apply redistribute {bgp | direct | ospf | rip | static | vrf WORD<1-16>}

Example

Switch:1> enable

Switch:1# configure terminal

Switch:1(config)# interface loopback 1

Switch:1(config-if)# ip address 192.0.2.2/8

Switch:1(config-if)# exit

Switch:1(config)# router isis

Switch:1(config-isis)# ip-source-address 192.0.2.2

Switch:1(config-isis)# spbm 1 ip enable

Switch:1(config-isis)# show isis spbm

show isis spbm

================================================================================
                                 ISIS SPBM Info
================================================================================
SPBM       B-VID      PRIMARY    NICK     LSDB     IP       IPV6     MULTICAST
INSTANCE              VLAN       NAME     TRAP
--------------------------------------------------------------------------------
1          4086-4087  4086       3.03.01  disable  enable  enable  disable

================================================================================
                              ISIS SPBM SMLT Info
================================================================================
SPBM       SMLT-SPLIT-BEB       SMLT-VIRTUAL-BMAC     SMLT-PEER-SYSTEM-ID
INSTANCE
--------------------------------------------------------------------------------
1          primary              00:00:03:03:03:03    0000.0303.0302


--------------------------------------------------------------------------------
 Total Num of SPBM instances: 1
--------------------------------------------------------------------------------

Switch:1(config-isis)# redistribute rip

Switch:1(config-isis)# redistribute rip enable

Switch:1(config-isis)# exit

Switch:1(config)# isis apply redistribute rip

Variable definitions

The following table defines parameters for the ip address command.


Variable	Value
`<1–256>`	Specifies an interface ID value. This value is optional.
`<A.B.C.D/X>`	Specifies an IP address and subnet mask. Use the no option to delete the specified IP address.
`<A.B.C.D>`	Specifies an IP address. Use the no option to delete the specified IP address.

The following table defines parameters for the ip-source-address command.


Variable	Value
`<A.B.C.D>`	Specifies the CLIP interface to use as the source address for SPBM IP shortcuts.

The following table defines parameters for the spbm command.


Variable	Value
`<1–100>` ip enable	Enables or disables SPBM IP shortcut state. The default is disabled. Use the no or default options to disable SPBM IP shortcuts.

The following table defines parameters for the redistribute command.


Variable	Value
{bgp \| direct \| ospf \| rip \| static}	Specifies the protocol.
enable	Enables the redistribution of the specified protocol into the SPBM network. The default is disabled. Use the no option to disable the redistribution.
metric `<0–65535>`	Configures the metric (cost) to apply to redistributed routes. The default is 1.
metric-type {external\|internal}	Configures the type of route to import into the protocol. The default is internal.
route-map `WORD<0–64>`	Configures the route policy to apply to redistributed routes. Type a name between 0 to 64 characters in length.
subnets {allow\|suppress}	Indicates whether the subnets are advertised individually or aggregated to their classful subnet. Choose suppress to advertise subnets aggregated to their classful subnet. Choose allow to advertise the subnets individually with the learned or configured mask of the subnet. The default is allow.

The following table defines parameters for the isis apply redistribute command.


Variable	Value
{bgp \| direct \| ospf \| rip \| static}	Specifies the protocol.