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 must 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
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. |