Understanding Label Space

This chapter contains configurations for Label Space. It also provides an overview of Label Space concepts.

Overview

The Label space refers to the scope of labels in a given LSR. It determines assignment and distribution of labels to a given peer. During data flow, it decides the key for looking up MPLS table and takes appropriate action based on the entry.

OcNOS supports per-platform label space, where a label must be unique for the entire platform. A label is interpreted the same way at all the interfaces. The FIB entry in the router does not contain incoming interface-related information. Thus the incoming traffic will be matched only with the label.

Topology

Figure 15. LDP Topology

PE1

PE1#configure terminal

Enter configure mode

PE1(config)#interface lo

Enter interface mode.

PE1(config-if)#ip address 1.1.1.1/32 secondary

Configure IP address for the loopback address

PE1(config-if)#exit

Exit interface mode

PE1(config)#interface xe6

Specify the interface (xe6)to be configured

PE1(config-if)#ip address 10.10.10.1/24

Configure IP address for the interface

PE1(config-if)#no shutdown

Administratively bringing up the interface

PE1(config-if)#exit

Exit interface mode

PE1(config)#router ospf 100

Configure the routing process and specify the Process ID (100)

PE1(config-router)#ospf router-id 1.1.1.1

Configure OSPF router ID same as loopback IP address

PE1(config-router)#network 10.10.10.0/24 area 0

PE1(config-router)#network 1.1.1.1/32 area 0

Define the interface on which OSPF runs and associate the area ID(0)with the interface

PE1(config-router)#exit

Exit configure mode

PE1(config)#router ldp

Enter router mode for LDP

PE1(config-router)#router-id 1.1.1.1

Set the router ID to IP address 1.1.1.1

PE1(config-router)#transport-address ipv4 1.1.1.1

Configure the transport address to be used for a TCP session over which LDP will run on an IPv4 interface. Note: It is preferable to use the loopback address as transport address. In addition, use the parameter "ipv6" if you are configuring an IPv6 interface.

PE1(config-router)# targeted-peer ipv4 3.3.3.3

Configure targeted peer.

PE1(config-router-targeted-peer)#exit

Exit from router target peer and LDP mode

PE1(config-if)#exit

Exit interface mode

PE1(config)#interface xe6

Specify the interface (xe6)to be configured

PE1(config-if)#label-switching

Enabling label switching capability on router

PE1(config-if)#enable-ldp ipv4

Enabling ldp on interface

PE1(config-if)#commit

Commit the transaction

P

P#configure terminal

Enter configure mode.

P(config)#interface lo

Enter interface mode.

P(config-if)#ip address 2.2.2.2/32 secondary

Configure IP address for the loopback address

P(config-if)#exit

Exit interface mode

P(config)#interface xe6

Specify the interface (xe6)to be configured

P(config-if)#ip address 10.10.10.2/24

Configure IP address for the interface

P(config-if)#no shutdown

Administratively bringing up the interface

P(config)#interface xe1

Specify the interface (xe1)to be configured

P(config-if)#ip address 20.20.20.1/24

Configure IP address for the interface

P(config)#router ospf 100

Configure the routing process and specify the Process ID (100)

P(config-router)#ospf router-id 2.2.2.2

Configure OSPF router ID same as loopback IP address

P(config-router)#network 10.10.10.0/24 area 0

P(config-router)#network 20.20.20.0/24 area 0

P(config-router)#network 2.2.2.2/32 area 0

Define the interface on which OSPF runs and associate the area ID (0)with the interface

P(config-router)#exit

Exit router mode

P(config)#router ldp

Enter router mode for LDP

P(config-router)#router-id 2.2.2.2

Set the router ID to IP address 2.2.2.2

P(config-router)#transport-address ipv4 2.2.2.2

Configure the transport address to be used for a TCP session over which LDP will run on an IPv4 interface. Note: It is preferable to use the loopback address as transport address. In addition, use the parameter "ipv6" if you are configuring an IPv6 interface.

P(config-router)#exit

Exit router mode for LDP

P(config)#mpls min-label-value 1000 max-label-value 50000 label-space 0

Configure the minimum label value and maximum label value to be used by Platform label space (Label space 0)

P(config)#interface xe6

Specify the interface (xe6)to be configured

P(config-if)#label-switching

Enabling label switching capability on router

P(config-if)#enable-ldp ipv4

Enabling ldp on interface

P(config-if)#exit

Exit interface mode

P(config)#interface xe1

Specify the interface (xe1) to be configured

P(config-if)#label-switching

Enabling label switching capability on router

P(config-if)#enable-ldp ipv4

Enabling ldp on interface

P(config-if)#commit

Commit the transaction

PE2

PE2#configure terminal

Enter configure mode.

PE2(config)#interface lo

Enter interface mode.

PE2(config-if)#ip address 3.3.3.3/32 secondary

Configure IP address for the loopback address

PE2(config-if)#exit

Exit interface mode

PE2(config)#interface xe1

Specify the interface (xe1)to be configured

PE2(config-if)#ip address 20.20.20.2/24

Configure IP address for the interface

PE2(config-if)#no shutdown

Administratively bringing up the interface

PE2(config-if)#exit

Exit interface mode

PE2(config)#router ospf 100

Configure the routing process and specify the Process ID (100)

PE2(config-router)#ospf router-id 3.3.3.3

Configure OSPF router ID same as loopback IP address

PE2(config-router)#network 20.20.20.0/24 area 0

PE2(config-router)#network 3.3.3.3/32 area 0

Define the interface on which OSPF runs and associate the area ID (0)with the interface

PE2(config-router)#exit

Exit router mode

PE2(config)#router ldp

Enter router mode for LDP

PE2(config-router)#router-id 3.3.3.3

Set the router ID to IP address 3.3.3.3

(config-router)#transport-address ipv4 3.3.3.3

Configure the transport address to be used for a TCP session over which LDP will run on an IPv4 interface. Note: It is preferable to use the loopback address as transport address. In addition, use the parameter "ipv6" if you are configuring an IPv6 interface.

PE2(config-router)# targeted-peer ipv4 1.1.1.1

Configure targeted peer

PE1(config-router-targeted-peer)#exit

Exit from router target peer and LDP mode

PE2(config-router)#exit

Exit router mode for LDP

PE2(config)#interface xe1

Specify the interface (xe1) to be configured

PE2(config-if)#label-switching

Enabling label switching capability on router

PE2(config-if)#enable-ldp ipv4

Enabling ldp on interface

PE2(config-if)#commit

Commit the transaction.

Validation

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PE1#show ldp
Router ID                : 1.1.1.1
LDP Version              : 1
Fast-reroute Per-prefix  : Disabled
Global Merge Capability  : Merge Capable
Label Advertisement Mode : Downstream Unsolicited
Label Retention Mode     : Liberal
Label Control Mode       : Independent
Instance Loop Detection  : Off
Request Retry            : Off
Propagate Release        : Disabled
Graceful Restart         : Disabled
Hello Interval           : 5
Targeted Hello Interval  : 15
Hold time                : 15
Targeted Hold time       : 45
Keepalive Interval       : 10
Keepalive Timeout        : 30
Request retry Timeout    : 5
Auto Targeted Hello Receipt   : Disabled
Transport Address data   :
  Labelspace 0           : 1.1.1.1 (in use)
Import BGP routes        : No
 
PE1#show ip ospf neighbor
 
Total number of full neighbors: 1
OSPF process 100 VRF(default):
Neighbor ID     Pri   State            Dead Time   Address         Interface           Instance ID
2.2.2.2           1   Full/Backup      00:00:30    10.10.10.2      xe1                    0

 

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P#show ldp
        
Router ID                : 2.2.2.2
LDP Version              : 1
Global Merge Capability  : Merge Capable
Label Advertisement Mode : Downstream Unsolicited
Label Retention Mode     : Liberal
Label Control Mode       : Independent
Instance Loop Detection  : Off
Request Retry            : Off
Propagate Release        : Disabled
Graceful Restart         : Disabled
Hello Interval           : 5
Targeted Hello Interval  : 15
Hold time                : 15
Targeted Hold time       : 45
Keepalive Interval       : 10
Keepalive Timeout        : 30
Request retry Timeout    : 5
Auto Targeted Hello Receipt: Disabled
Transport Address data   :
  Labelspace 0           : 2.2.2.2 (in use)
Import BGP routes        : No
 
P#show mpls label-space 0
 
Label range (min - max)         : 1000 - 50000
 
 module-static
      Default range             : 1000 - 3839
 
 module-srgb
      Default range (Usable)    : 3840 - 8739
      Default range (Allotted)  : 3840 - 8959
 
 module-srlb
      Default range (Usable)    : 8960 - 9959
      Default range (Allotted)  : 8960 - 10239
 
 module-rsvp
      Configured range          : N/A
      Current dynamic range     : N/A
 
 module-ldp
      Configured range          : Not configured
      Current dynamic range     : 10880 - 11519
 
 module-ldp-vc
      Configured range          : Not configured
      Current dynamic range     : 11520 - 12159
 
 module-bgp
      Configured range          : N/A
      Current dynamic range     : N/A
 
P#show ip ospf neighbor
 
Total number of full neighbors: 2
OSPF process 100 VRF(default):
Neighbor ID     Pri   State            Dead Time   Address         Interface           Instance ID
10.12.49.142      1   Full/DR          00:00:34    10.10.10.1      xe1                    0
10.12.49.158      1   Full/Backup      00:00:36    20.20.20.2      xe6                   0
 
P#show mpls ilm-table
Codes: > - installed ILM, * - selected ILM, p - stale ILM, ! - using backup
       K - CLI ILM, T - MPLS-TP, s - Stitched ILM
       S - SNMP, L - LDP, R - RSVP, C - CRLDP
       B - BGP , K - CLI , V - LDP_VC, I - IGP_SHORTCUT
       O - OSPF/OSPF6 SR, i - ISIS SR, k - SR CLI
       P - SR Policy, U - unknown
 
Code    FEC/VRF/L2CKT    ILM-ID      In-Label    Out-Label   In-Intf    Out-Intf/VRF       Nexthop                 pri    LSP-Type
   L>   1.1.1.1/32         2           10881       3           N/A        eth3             10.10.10.1              Yes    LSP_DEFAULT
   L>   3.3.3.3/32         1           10880       3           N/A        eth2             20.20.20.2              Yes    LSP_DEFAULT
 
PE2#show ldp
Router ID                : 3.3.3.3
LDP Version              : 1
Fast-reroute Per-prefix  : Disabled
Global Merge Capability  : Merge Capable
Label Advertisement Mode : Downstream Unsolicited
Label Retention Mode     : Liberal
Label Control Mode       : Independent
Instance Loop Detection  : Off
Request Retry            : Off
Propagate Release        : Disabled
Graceful Restart         : Disabled
Hello Interval           : 5
Targeted Hello Interval  : 15
Hold time                : 15
Targeted Hold time       : 45
Keepalive Interval       : 10
Keepalive Timeout        : 30
Request retry Timeout    : 5
Auto Targeted Hello Receipt   : Disabled
Transport Address data   :
  Labelspace 0           : 3.3.3.3 (in use)
Import BGP routes        : No
 
PE2#show ip ospf neighbor
 
Total number of full neighbors: 1
OSPF process 100 VRF(default):
Neighbor ID     Pri   State            Dead Time   Address         Interface           Instance ID
2.2.2.2           1   Full/Backup      00:00:29    20.20.20.1      xe1                    0