Display the IP Unicast FIB, Unicast FIB, and Unicast Tree
About this task
In SPBM, Backbone MAC (B-MAC) addresses are carried within the IS-IS link-state database. To do this, SPBM supports an IS-IS Type-Length-Value (TLV) that advertises the Service Instance Identifier (I-SID) and B-MAC information across the network. Each node has a System ID, which also serves as B-MAC of the switch. These B-MAC addresses are populated into the SPBM Forwarding Information Base (FIB).
When the network topology is discovered and stored in the IS-IS link-state database, each node calculates shortest path trees for each source node, so that a unicast path now exists from every node to every other node. With this information, each node populates unicast information received from SPBM into the FIB for forwarding purposes.
I-SIDs are only used for virtual services (Layer 2 VSNs and Layer 3 VSNs). If you only enable IP Shortcuts on the Backbone Edge Bridges, I-SIDs are never exchanged in the network as IP Shortcuts allow Global Routing Table (GRT) IP networks to be transported across IS-IS.
The show isis spbm ip-unicast-fib or show isis spbm ipv6-unicast-fib command displays all of the IS-IS routes in the IS-IS LSDB. The IP ROUTE PREFERENCE column in the show output displays the IP route preference.
Routes within the same VSN are added to the LSDB with a default preference of 7. Inter-VSN routes are added to the LSDB with a route preference of 200. IS-IS accept policies enable you to change the route preference for incoming routes. If the same route is learned from multiple sources with different route preferences, then the routes are not considered equal cost multipath (ECMP) routes. The route with the lowest route preference is the preferred route. In Layer 2, in the event of a tie-break between routes from multiple sources, the tie-breaking is based on cost and hop count.
Procedure
Examples
Switch# show isis spbm ip-unicast-fib
================================================================================================================
SPBM IP-UNICAST FIB ENTRY INFO
================================================================================================================
VRF DEST OUTGOING SPBM PREFIX PREFIX IP ROUTE
VRF ISID ISID Destination NH BEB VLAN INTERFACE COST COST TYPE PREFERENCE AREA AREA-NAME
----------------------------------------------------------------------------------------------------------------
GRT - - 10.133.136.0/24 4K3(*) 4058 1/3 10 1 Internal 7 HOME area-9.00.02
GRT - - 10.133.136.0/24 4K3(*) 4059 1/3 10 1 Internal 7 HOME area-9.00.02
GRT - - 10.133.136.0/24 4K4(*) 4058 to_4k4 10000 1 Internal 7 HOME area-9.00.02
GRT - - 10.133.136.0/24 4K4(*) 4059 to_4k4 10000 1 Internal 7 HOME area-9.00.02
----------------------------------------------------------------------------------------------------------------
Home : Total number of SPBM IP-UNICAST FIB entries 4
Remote: Total number of SPBM IP-UNICAST FIB entries 0
----------------------------------------------------------------------------------------------------------------
Switch# show isis spbm unicast-fib
==================================================================================================
SPBM UNICAST FIB ENTRY INFO
==================================================================================================
DESTINATION BVLAN SYSID HOST-NAME OUTGOING COST AREA AREA-NAME
ADDRESS INTERFACE
--------------------------------------------------------------------------------------------------
00:16:ca:23:73:df 1000 0016.ca23.73df SPBM-1 1/21 10 HOME area-9.00.02
00:16:ca:23:73:df 2000 0016.ca23.73df SPBM-1 1/21 10 HOME area-9.00.02
00:18:b0:bb:b3:df 1000 0018.b0bb.b3df SPBM-2 MLT-2 10 HOME area-9.00.02
00:14:c7:e1:33:e0 1000 0018.b0bb.b3df SPBM-2 MLT-2 10 HOME area-9.00.02
00:18:b0:bb:b3:df 2000 0018.b0bb.b3df SPBM-2 MLT-2 10 HOME area-9.00.02
--------------------------------------------------------------------------------------------------
Home: Total number of SPBM UNICAST FIB entries 5
Remote: Total number of SPBM UNICAST FIB entries 0
--------------------------------------------------------------------------------------------------
Variable Definitions
The following table defines parameters for the show isis spbm ip-unicast-fib command.
|
Variable |
Value |
|---|---|
|
all |
Displays entries for the Global Routing Table (GRT) and all Virtual Routing and Forwarding (VRF) instances. Note:
If you use the command show isis spbm ip-unicast-fib the device displays only GRT entries. The command shows IP routes from remote Backbone Edge Bridges (BEBs). |
|
home |
Displays the IS-IS SPBM IP unicast Forwarding Information Base (FIB) information that the system configures in the home area. |
|
id <1–16777215> |
Displays IS-IS SPBM IP unicast FIB information by Service Instance Identifier (I-SID) ID. |
|
remote |
Displays the IS-IS SPBM IP unicast FIB information that the system configures in the remote area. |
|
spbm-nh-as-mac |
Displays the next hop B-MAC of the IP unicast FIB entry. |
The following table defines parameters for the show isis spbm ipv6-unicast-fib command.
|
Variable |
Value |
|---|---|
|
all |
Displays entries for the Global Routing Table (GRT) and all Virtual Routing and Forwarding (VRF) instances. Note:
If you use the command show isis spbm ipv6-unicast-fib the device displays only GRT entries. The command shows IPv6 routes from remote Backbone Edge Bridges (BEBs). |
|
home |
Displays the IS-IS SPBM IPv6 unicast Forwarding Information Base (FIB) information that the system configures in the home area. |
|
id <1–16777215> |
Displays IS-IS SPBM IPv6 unicast FIB information by Service Instance Identifier (I-SID) ID. |
|
remote |
Displays the IS-IS SPBM IPv6 unicast FIB information that the system configures in the remote area. |
|
spbm-nh-as-mac |
Displays the next hop as MAC of the IPv6 unicast FIB entry. |
The following table defines parameters for the show isis spbm unicast-fib command.
|
Variable |
Value |
|---|---|
|
b-mac <0x00:0x00:0x00:0x00:0x00:0x00> |
Displays the FIB for the specified BMAC. |
|
home |
Displays the IS-IS SPBM unicast Forwarding Information Base (FIB) information that the system configures in the home area. |
|
remote |
Displays the IS-IS SPBM unicast FIB information that the system configures in the remote area. |
|
vlan <1-4059> |
Displays the FIB for the specified SPBM VLAN. |
|
summary |
Displays a summary of the FIB. |
The following table defines parameters for the show isis spbm unicast-tree command.
|
Variable |
Value |
|---|---|
|
<1-4059> |
Specifies the SPBM B-VLAN ID. |
|
destination <xxxx.xxxx.xxxx> |
Displays the unicast tree for the specified destination. |