FNS技術研究所
FNS技術研究所

MPLS (Multiprotocol Label SwitchingでRFC 3031により規程)

例）下図のようにCiscoルーター4台構成にて簡単なMPLSネットワークを構築し、デフォルトプロトコルの
LDP(Label Distrubution Protocol)によるラベルスイッチングが行われているか確認。

#ref error ：ご指定のファイルが見つかりません。ファイル名を確認して、再度指定してください。 (mpls-network.png)
LDPはneighborとの通信確立のために、RouterIDを用いた疎通が必須のため、OSPF等のIGPでのルート通知が必要。
複数のLoopbackが在る場合は最大IPが優先されるため、「mpls ldp router-id loopback0 force」等でLoopbackを指定可能
参考：MPLSのトラブル 【CCIEレベル】

PE-1ルータ(Provider Edge)

PE-1ルータのconfig 
interface Loopback0
 ip address 10.0.0.3 255.255.255.255
!
interface GigabitEthernet0/0
 ip address 192.168.252.238 255.255.255.252
 duplex auto
 speed auto
!
interface GigabitEthernet0/1
 ip address 192.168.252.241 255.255.255.252
 duplex auto
 speed auto
 mpls ip
!
router ospf 1
 log-adjacency-changes
 network 10.0.0.3 0.0.0.0 area 0
 network 192.168.252.238 0.0.0.0 area 0
 network 192.168.252.241 0.0.0.0 area 0
!
PE-1ルータのルーティングテーブル 
PE-1#show ip route
Gateway of last resort is not set

     10.0.0.0/32 is subnetted, 4 subnets
C       10.0.0.3 is directly connected, Loopback0
O       10.0.0.6 [110/4] via 192.168.252.242, 00:04:56, GigabitEthernet0/1
O       10.0.0.4 [110/2] via 192.168.252.242, 00:04:56, GigabitEthernet0/1
O       10.0.0.5 [110/3] via 192.168.252.242, 00:04:56, GigabitEthernet0/1
     192.168.252.0/30 is subnetted, 5 subnets
O       192.168.252.244 [110/2] via 192.168.252.242, 00:04:56, GigabitEthernet0/1
C       192.168.252.240 is directly connected, GigabitEthernet0/1
O       192.168.252.252 [110/4] via 192.168.252.242, 00:04:56, GigabitEthernet0/1
O       192.168.252.248 [110/3] via 192.168.252.242, 00:04:56, GigabitEthernet0/1
C       192.168.252.236 is directly connected, GigabitEthernet0/0
PE-1ルータのフォワーディングテーブル 
PE-1#show mpls forwarding-table
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop
tag    tag or VC   or Tunnel Id      switched   interface
16     Pop tag     10.0.0.4/32       0          Gi0/1      192.168.252.242
17     Pop tag     192.168.252.244/30   \
                                     0          Gi0/1      192.168.252.242
18     19          10.0.0.5/32       0          Gi0/1      192.168.252.242
19     16          192.168.252.248/30   \
                                     0          Gi0/1      192.168.252.242
20     17          192.168.252.252/30   \
                                     0          Gi0/1      192.168.252.242
21     20          10.0.0.6/32       0          Gi0/1      192.168.252.242

P-1ルータ(Provider)

P-1ルータのconfig 
interface Loopback0
 ip address 10.0.0.4 255.255.255.255
!
interface GigabitEthernet0/0
 ip address 192.168.252.242 255.255.255.252
 duplex auto
 speed auto
 mpls ip
!
interface GigabitEthernet0/1
 ip address 192.168.252.245 255.255.255.252
 duplex auto
 speed auto
 mpls ip
!
router ospf 1
 network 10.0.0.4 0.0.0.0 area 0
 network 192.168.252.242 0.0.0.0 area 0
 network 192.168.252.245 0.0.0.0 area 0
!
P-1ルータのルーティングテーブル 
P-1#show ip route
Gateway of last resort is not set

      10.0.0.0/32 is subnetted, 4 subnets
O        10.0.0.3 [110/2] via 192.168.252.241, 00:26:06, GigabitEthernet0/0
C        10.0.0.4 is directly connected, Loopback0
O        10.0.0.5 [110/2] via 192.168.252.246, 00:21:54, GigabitEthernet0/1
O        10.0.0.6 [110/3] via 192.168.252.246, 00:17:14, GigabitEthernet0/1
      192.168.252.0/24 is variably subnetted, 7 subnets, 2 masks
O        192.168.252.236/30 [110/2] via 192.168.252.241, 00:12:23, GigabitEthernet0/0
C        192.168.252.240/30 is directly connected, GigabitEthernet0/0
L        192.168.252.242/32 is directly connected, GigabitEthernet0/0
C        192.168.252.244/30 is directly connected, GigabitEthernet0/1
L        192.168.252.245/32 is directly connected, GigabitEthernet0/1
O        192.168.252.248/30 [110/2] via 192.168.252.246, 00:21:44, GigabitEthernet0/1
O        192.168.252.252/30 [110/3] via 192.168.252.246, 00:20:26, GigabitEthernet0/1
P-1ルータのフォワーディングテーブル 
P-1#show mpls forwarding-table
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop
Label      Label      or Tunnel Id     Switched      interface
16         Pop Label  192.168.252.248/30   \
                                       570           Gi0/1      192.168.252.246
17         19         192.168.252.252/30   \
                                       0             Gi0/1      192.168.252.246
18         Pop Label  10.0.0.3/32      570           Gi0/0      192.168.252.241
19         Pop Label  10.0.0.5/32      0             Gi0/1      192.168.252.246
20         20         10.0.0.6/32      2950          Gi0/1      192.168.252.246
21         Pop Label  192.168.252.236/30   \
                                       1140          Gi0/0      192.168.252.241

P-2ルータ(Provider)

P-2ルータのconfig 
interface Loopback0
 ip address 10.0.0.5 255.255.255.255
!
interface GigabitEthernet0/0
 ip address 192.168.252.246 255.255.255.252
 duplex auto
 speed auto
!
interface GigabitEthernet0/1
 ip address 192.168.252.249 255.255.255.252
 duplex auto
 speed auto
 mpls ip
!
router ospf 1
 network 10.0.0.5 0.0.0.0 area 0
 network 192.168.252.246 0.0.0.0 area 0
 network 192.168.252.249 0.0.0.0 area 0
!
P-2ルータのルーティングテーブル 
P-2#show ip route
Gateway of last resort is not set

      10.0.0.0/32 is subnetted, 4 subnets
O        10.0.0.3 [110/3] via 192.168.252.245, 00:30:05, GigabitEthernet0/0
O        10.0.0.4 [110/2] via 192.168.252.245, 00:30:05, GigabitEthernet0/0
C        10.0.0.5 is directly connected, Loopback0
O        10.0.0.6 [110/2] via 192.168.252.250, 00:25:25, GigabitEthernet0/1
      192.168.252.0/24 is variably subnetted, 7 subnets, 2 masks
O        192.168.252.236/30 [110/3] via 192.168.252.245, 00:20:34, GigabitEthernet0/0
O        192.168.252.240/30 [110/2] via 192.168.252.245, 00:30:05, GigabitEthernet0/0
C        192.168.252.244/30 is directly connected, GigabitEthernet0/0
L        192.168.252.246/32 is directly connected, GigabitEthernet0/0
C        192.168.252.248/30 is directly connected, GigabitEthernet0/1
L        192.168.252.249/32 is directly connected, GigabitEthernet0/1
O        192.168.252.252/30 [110/2] via 192.168.252.250, 00:28:47, GigabitEthernet0/1
P-2ルータのフォワーディングテーブル 
P-2#show mpls forwarding-table
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop
Label      Label      or Tunnel Id     Switched      interface
16         Pop Label  10.0.0.4/32      0             Gi0/0      192.168.252.245
17         18         10.0.0.3/32      590           Gi0/0      192.168.252.245
18         Pop Label  192.168.252.240/30   \
                                       1140          Gi0/0      192.168.252.245
19         Pop Label  192.168.252.252/30   \
                                       0             Gi0/1      192.168.252.250
20         Pop Label  10.0.0.6/32      2850          Gi0/1      192.168.252.250
21         21         192.168.252.236/30   \
                                       1180          Gi0/0      192.168.252.245

PE-2ルータ(Provider Edge)

PE-2ルータのconfig 
interface Loopback0
 ip address 10.0.0.6 255.255.255.255
 !
!
interface GigabitEthernet0/0
 ip address 192.168.252.250 255.255.255.252
 duplex auto
 speed auto
 mpls ip
 !
!
interface GigabitEthernet0/1
 ip address 192.168.252.253 255.255.255.252
 duplex auto
 speed auto
 !
!
router ospf 1
 log-adjacency-changes
 network 10.0.0.6 0.0.0.0 area 0
 network 192.168.252.250 0.0.0.0 area 0
 network 192.168.252.253 0.0.0.0 area 0
 network 192.168.253.246 0.0.0.0 area 0
!
PE-2ルータのルーティングテーブル 
PE-2#show ip route
Gateway of last resort is not set

      10.0.0.0/32 is subnetted, 4 subnets
O        10.0.0.3 [110/4] via 192.168.252.249, 00:37:20, GigabitEthernet0/0
O        10.0.0.4 [110/3] via 192.168.252.249, 00:37:20, GigabitEthernet0/0
O        10.0.0.5 [110/2] via 192.168.252.249, 00:37:20, GigabitEthernet0/0
C        10.0.0.6 is directly connected, Loopback0
      192.168.252.0/24 is variably subnetted, 7 subnets, 2 masks
O        192.168.252.236/30 [110/4] via 192.168.252.249, 00:29:06, GigabitEthernet0/0
O        192.168.252.240/30 [110/3] via 192.168.252.249, 00:37:21, GigabitEthernet0/0
O        192.168.252.244/30 [110/2] via 192.168.252.249, 00:37:21, GigabitEthernet0/0
C        192.168.252.248/30 is directly connected, GigabitEthernet0/0
L        192.168.252.250/32 is directly connected, GigabitEthernet0/0
C        192.168.252.252/30 is directly connected, GigabitEthernet0/1
L        192.168.252.253/32 is directly connected, GigabitEthernet0/1
PE-2ルータのフォワーディングテーブル 
PE-2#show mpls forwarding-table
Local      Outgoing   Prefix           Bytes Label   Outgoing   Next Hop
Label      Label      or Tunnel Id     Switched      interface
16         Pop Label  10.0.0.5/32      0             Gi0/0      192.168.252.249
17         Pop Label  192.168.252.244/30   \
                                       0             Gi0/0      192.168.252.249
18         17         10.0.0.3/32      0             Gi0/0      192.168.252.249
19         18         192.168.252.240/30   \
                                       0             Gi0/0      192.168.252.249
20         16         10.0.0.4/32      0             Gi0/0      192.168.252.249
21         21         192.168.252.236/30   \
                                       0             Gi0/0      192.168.252.249

動作確認

上記の設定にてPE-1のクラウド側よりPE-2のクラウド側にpingを実行する。この時、P-1、P-2でmplsのデバッグを行い通過パケットのラベルを確認する。

PE-1ルータの送信元IP(192.168.252.238)よりPE-2ルータへ送信先IP(192.168.252.253)へping実行する。

PE-1#ping 192.168.252.253 source 192.168.252.238

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.252.253, timeout is 2 seconds:
Packet sent with a source address of 192.168.252.238
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms

P-1ルータのデバッグ

P-1#debug mpls packet
P-1#
*Feb 19 15:27:07.950: MPLS les: Gi0/0: rx: Len 118 Stack {17 0 255} - ipv4 data
*Feb 19 15:27:07.950: MPLS les: Gi0/1: tx: Len 118 Stack {19 0 254} - ipv4 data
*Feb 19 15:27:07.954: MPLS les: Gi0/1: rx: Len 118 Stack {21 0 254} - ipv4 data
*Feb 19 15:27:07.954: MPLS les: Gi0/0: rx: Len 118 Stack {17 0 255} - ipv4 data
*Feb 19 15:27:07.954: MPLS les: Gi0/1: tx: Len 118 Stack {19 0 254} - ipv4 data
*Feb 19 15:27:07.954: MPLS les: Gi0/1: rx: Len 118 Stack {21 0 254} - ipv4 data
*Feb 19 15:27:07.954: MPLS les: Gi0/0: rx: Len 118 Stack {17 0 255} - ipv4 data
*Feb 19 15:27:07.954: MPLS les: Gi0/1: tx: Len 118 Stack {19 0 254} - ipv4 data
P-1#
*Feb 19 15:27:07.954: MPLS les: Gi0/1: rx: Len 118 Stack {21 0 254} - ipv4 data
*Feb 19 15:27:07.958: MPLS les: Gi0/0: rx: Len 118 Stack {17 0 255} - ipv4 data
*Feb 19 15:27:07.958: MPLS les: Gi0/1: tx: Len 118 Stack {19 0 254} - ipv4 data
*Feb 19 15:27:07.958: MPLS les: Gi0/1: rx: Len 118 Stack {21 0 254} - ipv4 data
*Feb 19 15:27:07.958: MPLS les: Gi0/0: rx: Len 118 Stack {17 0 255} - ipv4 data
*Feb 19 15:27:07.958: MPLS les: Gi0/1: tx: Len 118 Stack {19 0 254} - ipv4 data
*Feb 19 15:27:07.958: MPLS les: Gi0/1: rx: Len 118 Stack {21 0 254} - ipv4 data

P-2ルータのデバッグ

P-2#debug mpls packet
P-2#
*Feb 19 15:18:27.138: MPLS les: Gi0/0: rx: Len 118 Stack {19 0 254} - ipv4 data
*Feb 19 15:18:27.138: MPLS les: Gi0/1: rx: Len 118 Stack {21 0 255} - ipv4 data
*Feb 19 15:18:27.138: MPLS les: Gi0/0: tx: Len 118 Stack {21 0 254} - ipv4 data
*Feb 19 15:18:27.142: MPLS les: Gi0/0: rx: Len 118 Stack {19 0 254} - ipv4 data
*Feb 19 15:18:27.142: MPLS les: Gi0/1: rx: Len 118 Stack {21 0 255} - ipv4 data
*Feb 19 15:18:27.142: MPLS les: Gi0/0: tx: Len 118 Stack {21 0 254} - ipv4 data
*Feb 19 15:18:27.142: MPLS les: Gi0/0: rx: Len 118 Stack {19 0 254} - ipv4 data
*Feb 19 15:18:27.142: MPLS les: Gi0/1: rx: Len 118 Stack {21 0 255} - ipv4 data
P-2#
*Feb 19 15:18:27.142: MPLS les: Gi0/0: tx: Len 118 Stack {21 0 254} - ipv4 data
*Feb 19 15:18:27.146: MPLS les: Gi0/0: rx: Len 118 Stack {19 0 254} - ipv4 data
*Feb 19 15:18:27.146: MPLS les: Gi0/1: rx: Len 118 Stack {21 0 255} - ipv4 data
*Feb 19 15:18:27.146: MPLS les: Gi0/0: tx: Len 118 Stack {21 0 254} - ipv4 data
*Feb 19 15:18:27.146: MPLS les: Gi0/0: rx: Len 118 Stack {19 0 254} - ipv4 data
*Feb 19 15:18:27.146: MPLS les: Gi0/1: rx: Len 118 Stack {21 0 255} - ipv4 data
*Feb 19 15:18:27.146: MPLS les: Gi0/0: tx: Len 118 Stack {21 0 254} - ipv4 data

参考：MPLSの基本
参考：MPLSとは
「MPLS」をウィキ内検索
最終更新：2013年02月20日 02:12
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