Segment Routing.png

 

In this post , we will simulate how to configure segment routing (basic configuration)

The running IGP is ISIS level 2

 

R1#ping 192.168.203.20
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.203.20, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

 

CSR1#show mpls forwarding-table
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop
Label      Label      or Tunnel Id     Switched      interface
16         No Label   192.168.101.0/24[V]   \
                                       0             aggregate/MSSK
CSR2#show mpls forwarding-table
no MPLS apps enabled or MPLS not enabled on any interfaces

CSR3#show mpls forwarding-table
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop
Label      Label      or Tunnel Id     Switched      interface
16         No Label   192.168.203.0/24[V]   \
                                       0             aggregate/MSSK

 

CSR1:
segment-routing mpls
connected-prefix-sid-map
  address-family ipv4
   1.1.1.1/32 index 100
  exit-address-family

router isis 1
segment-routing mpls

CSR2:
segment-routing mpls
connected-prefix-sid-map
  address-family ipv4
   2.2.2.2/32 index 200
  exit-address-family

router isis 1
segment-routing mpls

CSR3:
segment-routing mpls
connected-prefix-sid-map
  address-family ipv4
   3.3.3.3/32 index 300
  exit-address-family

router isis 1
segment-routing mpls

 

CSR1#show mpls forwarding-table
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop
Label      Label      or Tunnel Id     Switched      interface
16         No Label   192.168.101.0/24[V]   \
                                       570           aggregate/MSSK
17         Pop Label  0000.0000.0002-Gi1-192.168.12.2   \
                                       0             Gi1        192.168.12.2
16200      Pop Label  2.2.2.2/32       0             Gi1        192.168.12.2
16300      16300      3.3.3.3/32       0             Gi1        192.168.12.2

CSR2#show mpls forwarding-table
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop
Label      Label      or Tunnel Id     Switched      interface
16         Pop Label  0000.0000.0001-Gi1-192.168.12.1   \
                                       0             Gi1        192.168.12.1
17         Pop Label  0000.0000.0003-Gi2-192.168.23.3   \
                                       0             Gi2        192.168.23.3
16100      Pop Label  1.1.1.1/32       1098          Gi1        192.168.12.1
16300      Pop Label  3.3.3.3/32       1098          Gi2        192.168.23.3

CSR3#show mpls forwarding-table
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop
Label      Label      or Tunnel Id     Switched      interface
16         No Label   192.168.203.0/24[V]   \
                                       570           aggregate/MSSK
17         Pop Label  0000.0000.0002-Gi1-192.168.23.2   \
                                       0             Gi1        192.168.23.2
16100      16100      1.1.1.1/32       0             Gi1        192.168.23.2
16200      Pop Label  2.2.2.2/32       0             Gi1        192.168.23.2

CSR1#show ip cef 3.3.3.3/32
3.3.3.3/32
  nexthop 192.168.12.2 GigabitEthernet1 label 16300()

CSR3#show ip cef 1.1.1.1/32
1.1.1.1/32
  nexthop 192.168.23.2 GigabitEthernet1 label 16100()

 

CSR1#show isis segment-routing
ISIS protocol is registered with MFI
ISIS MFI Client ID:0x63
Tag 1 - Segment-Routing:
   SR State:SR_ENABLED
   Number of SRGB:1
   SRGB Start:16000, Range:8000, srgb_handle:0x7F25A007F490, srgb_state: created
   Address-family IPv4 unicast SR is configured
     Operational state:Enabled
     Receive is enabled
     Advertise local is disabled
     Explicit null is disabled
     SR label preferred is disabled

CSR3#show isis segment-routing
ISIS protocol is registered with MFI
ISIS MFI Client ID:0x63
Tag 1 - Segment-Routing:
   SR State:SR_ENABLED
   Number of SRGB:1
   SRGB Start:16000, Range:8000, srgb_handle:0x7FBE8DB056F8, srgb_state: created
   Address-family IPv4 unicast SR is configured
     Operational state:Enabled
     Receive is enabled
     Advertise local is disabled
     Explicit null is disabled
     SR label preferred is disabled

CSR1#show segment-routing mpls state
Segment Routing MPLS State : ENABLED

CSR3#show segment-routing mpls state
Segment Routing MPLS State : ENABLED

 

CSR1#show isis database level-2 verbose

Tag 1:
IS-IS Level-2 Link State Database:
LSPID                 LSP Seq Num  LSP Checksum  LSP Holdtime      ATT/P/OL
CSR1.00-00          * 0x00000005   0xECC1        383               0/0/0
  Area Address: 49.0001
  NLPID:        0xCC
  Router CAP:   1.1.1.1, D:0, S:0
    Segment Routing: I:1 V:0, SRGB Base: 16000 Range: 8000
  Hostname: CSR1
  Metric: 10         IS-Extended CSR2.01
    Lan Adjacency SID:
      SID Value:17, CSR2, F:0 B:0 V:1 L:1 S:0 Weight:0
  IP Address:   1.1.1.1
  Metric: 10         IP 1.1.1.1/32
    Prefix-SID Index: 100, Algorithm:0, R:0 N:1 P:0 E:0 V:0 L:0
  Metric: 10         IP 192.168.12.0/24
  Metric: 10         IP 192.168.22.0/24
CSR2.00-00            0x00000006   0xFD8D        1181              0/0/0
  Area Address: 49.0001
  NLPID:        0xCC
  Router CAP:   2.2.2.2, D:0, S:0
    Segment Routing: I:1 V:0, SRGB Base: 16000 Range: 8000
  Hostname: CSR2
  Metric: 10         IS-Extended CSR2.01
    Lan Adjacency SID:
      SID Value:16, CSR1, F:0 B:0 V:1 L:1 S:0 Weight:0
  Metric: 10         IS-Extended CSR3.01
    Lan Adjacency SID:
      SID Value:17, CSR3, F:0 B:0 V:1 L:1 S:0 Weight:0
  IP Address:   2.2.2.2
  Metric: 10         IP 2.2.2.2/32
    Prefix-SID Index: 200, Algorithm:0, R:0 N:1 P:0 E:0 V:0 L:0
  Metric: 10         IP 192.168.12.0/24
  Metric: 10         IP 192.168.122.0/24
  Metric: 10         IP 192.168.23.0/24
CSR2.01-00            0x00000002   0x7C4C        934               0/0/0
  Metric: 0          IS-Extended CSR2.00
  Metric: 0          IS-Extended CSR1.00
CSR3.00-00            0x00000005   0x0B43        1157              0/0/0
  Area Address: 49.0001
  NLPID:        0xCC
  Router CAP:   3.3.3.3, D:0, S:0
    Segment Routing: I:1 V:0, SRGB Base: 16000 Range: 8000
  Hostname: CSR3
  Metric: 10         IS-Extended CSR3.01
    Lan Adjacency SID:
      SID Value:17, CSR2, F:0 B:0 V:1 L:1 S:0 Weight:0
  IP Address:   3.3.3.3
  Metric: 10         IP 3.3.3.3/32
    Prefix-SID Index: 300, Algorithm:0, R:0 N:1 P:0 E:0 V:0 L:0
  Metric: 10         IP 192.168.23.0/24
  Metric: 10         IP 192.168.133.0/24
CSR3.01-00            0x00000002   0x9134        882               0/0/0
  Metric: 0          IS-Extended CSR3.00
  Metric: 0          IS-Extended CSR2.00

R1#ping 192.168.203.20
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.203.20, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/56/72 ms