H O M E > ネットワークのおべんきょしませんか? Cisco CCNA/CCNP/CCIE、ネットワークスペシャリスト試験の勉強にピッタリ > 2010年4月
(所属カテゴリー:IPルーティング | シスコ---投稿日時:2010年4月16日)
下記のネットワーク構成で、MPLS-VPNを通じてR4とR5間の通信ができるようにしたいと考えています。
ルータの役割は、次の通りです。
PEルータ:R1、R3
Pルータ :R2
CEルータ:R4、R5
PEルータであるR1、R3ではともにVRFとして次のように定義します。
VRF名:VPN
RD:100:100
Import RT:100:100
Export RT:100:100
各ルータで行われているMPLS-VPNでの通信に関連する設定は次の通りです。
R1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ip vrf VPN rd 100:100 route-target export 100:100 route-target import 100:101 ! interface Loopback0 ip address 192.168.0.1 255.255.255.255 ! interface FastEthernet0/0 ip vrf forwarding VPN ip address 10.14.14.1 255.255.255.0 ! interface Serial1/0 ip address 192.168.12.1 255.255.255.0 encapsulation ppp mpls ip no peer neighbor-route ! router ospf 14 vrf VPN log-adjacency-changes redistribute bgp 100 subnets network 10.14.14.1 0.0.0.0 area 0 ! router ospf 1 log-adjacency-changes network 192.168.0.0 0.0.255.255 area 0 ! router bgp 100 no synchronization bgp log-neighbor-changes neighbor 192.168.0.3 remote-as 100 neighbor 192.168.0.3 update-source Loopback0 no auto-summary ! address-family vpnv4 neighbor 192.168.0.3 activate neighbor 192.168.0.3 send-community extended exit-address-family ! address-family ipv4 vrf VPN no synchronization exit-address-family ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R2 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ interface Loopback0 ip address 192.168.0.2 255.255.255.255 ! interface Serial1/0 ip address 192.168.12.2 255.255.255.0 encapsulation ppp mpls ip no peer neighbor-route ! interface Serial1/1 ip address 192.168.23.2 255.255.255.0 encapsulation ppp mpls ip no peer neighbor-route ! router ospf 1 log-adjacency-changes network 192.168.0.0 0.0.255.255 area 0 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R3 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ip vrf VPN rd 100:100 route-target export 100:100 route-target import 100:100 ! interface Loopback0 ip address 192.168.0.3 255.255.255.255 ! interface FastEthernet0/0 ip vrf forwarding VPN ip address 10.35.35.3 255.255.255.0 duplex auto speed auto ! interface Serial1/0 ip address 192.168.23.3 255.255.255.0 encapsulation ppp mpls ip no peer neighbor-route ! router ospf 35 vrf VPN log-adjacency-changes redistribute bgp 100 subnets network 10.35.35.3 0.0.0.0 area 0 ! router ospf 1 log-adjacency-changes network 192.168.0.0 0.0.255.255 area 0 ! router bgp 100 no synchronization bgp log-neighbor-changes neighbor 192.168.0.1 remote-as 100 neighbor 192.168.0.1 update-source Loopback0 no auto-summary ! address-family vpnv4 neighbor 192.168.0.1 activate neighbor 192.168.0.1 send-community extended exit-address-family ! address-family ipv4 vrf VPN redistribute ospf 35 vrf VPN no synchronization exit-address-family ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R4 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ interface Loopback0 ip address 172.16.4.4 255.255.255.0 ip ospf network point-to-point ! interface FastEthernet0/0 ip address 10.14.14.4 255.255.255.0 ! router ospf 1 log-adjacency-changes network 10.14.14.4 0.0.0.0 area 0 network 172.16.4.4 0.0.0.0 area 0 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R5 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ interface Loopback0 ip address 172.16.5.5 255.255.255.0 ip ospf network point-to-point ! interface FastEthernet0/0 ip address 10.35.35.5 255.255.255.0 ! router ospf 1 log-adjacency-changes network 10.35.35.5 0.0.0.0 area 0 network 172.16.5.5 0.0.0.0 area 0 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
R4、R5でルーティングテーブルを見るとお互いのルートを確認できません。そのため、当然、通信が不可能な状態になってしまっています。R4のルーティングテーブルと、R5への通信の結果は次のようになっています。
R4 show ip route/ping 172.16.5.5 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R4#sh ip route ~省略~ Gateway of last resort is not set 172.16.0.0/24 is subnetted, 1 subnets C 172.16.4.0 is directly connected, Loopback0 10.0.0.0/24 is subnetted, 1 subnets C 10.14.14.0 is directly connected, FastEthernet0/0 R4#ping 172.16.5.5 source 172.16.4.4 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.5.5, timeout is 2 seconds: Packet sent with a source address of 172.16.4.4 ..... Success rate is 0 percent (0/5) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
PEルータであるR1、R3とCEルータであるR4、R5はOSPFでルーティングを行っています。ネイバーを確認すると、次のように正常にOSPFネイバーを確認できています。
R4 show ip ospf neighbor ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R4#sh ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.14.14.1 1 FULL/BDR 00:00:34 10.14.14.1 FastEthernet0/0 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R5 show ip ospf neighbor ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 5#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.35.35.3 1 FULL/BDR 00:00:38 10.35.35.3 FastEthernet0/0 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
そのため、PE-CE間のルーティングには特に問題がないと考えられます。問題はMPLSバックボーンにある可能性が高いです。そこでMPLSバックボーンを構成するR1、R2、R3で次のshowコマンドで原因の切り分けを行いました。
R1 show mpls interface show mpls ldp neighbor show ip vrf detail show ip bgp vpnv4 all show ip route vrf VPN R2 show mpls interface show mpls ldp neighbor R3 show mpls interface show mpls ldp neighbor show ip vrf detail show ip bgp vpnv4 all show ip route vrf VPN R1 showコマンドの結果 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R1#show mpls interface Interface IP Tunnel Operational Serial1/0 Yes (ldp) No Yes R1#show mpls ldp neighbor Peer LDP Ident: 192.168.0.2:0; Local LDP Ident 192.168.0.1:0 TCP connection: 192.168.0.2.18981 - 192.168.0.1.646 State: Oper; Msgs sent/rcvd: 27/27; Downstream Up time: 00:17:08 LDP discovery sources: Serial1/0, Src IP addr: 192.168.12.2 Addresses bound to peer LDP Ident: 192.168.12.2 192.168.0.2 192.168.23.2 R1#show ip vrf detail VRF VPN; default RD 100:100; default VPNIDInterfaces: Fa0/0 Connected addresses are not in global routing table Export VPN route-target communities RT:100:100 Import VPN route-target communities RT:100:101 No import route-map No export route-map VRF label distribution protocol: not configured R1#show ip bgp vpnv4 all R1#show ip route vrf VPN Routing Table: VPN Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route Gateway of last resort is not set 172.16.0.0/24 is subnetted, 1 subnets O 172.16.4.0 [110/2] via 10.14.14.4, 00:16:35, FastEthernet0/0 10.0.0.0/24 is subnetted, 1 subnets C 10.14.14.0 is directly connected, FastEthernet0/0 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R2 showコマンドの結果 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R2#show mpls interface Interface IP Tunnel Operational Serial1/0 Yes (ldp) No Yes Serial1/1 Yes (ldp) No Yes R2#show mpls ldp neighbor Peer LDP Ident: 192.168.0.1:0; Local LDP Ident 192.168.0.2:0 TCP connection: 192.168.0.1.646 - 192.168.0.2.18981 State: Oper; Msgs sent/rcvd: 28/29; Downstream Up time: 00:18:12 LDP discovery sources: Serial1/0, Src IP addr: 192.168.12.1 Addresses bound to peer LDP Ident: 192.168.0.1 192.168.12.1 Peer LDP Ident: 192.168.0.3:0; Local LDP Ident 192.168.0.2:0 TCP connection: 192.168.0.3.20001 - 192.168.0.2.646 State: Oper; Msgs sent/rcvd: 29/28; Downstream Up time: 00:18:10 LDP discovery sources: Serial1/1, Src IP addr: 192.168.23.3 Addresses bound to peer LDP Ident: 192.168.0.3 192.168.23.3 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R3 showコマンドの結果 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ R3#show mpls interface Interface IP Tunnel Operational Serial1/0 Yes (ldp) No Yes R3#show mpls ldp neighbor Peer LDP Ident: 192.168.0.2:0; Local LDP Ident 192.168.0.3:0 TCP connection: 192.168.0.2.646 - 192.168.0.3.20001 State: Oper; Msgs sent/rcvd: 29/30; Downstream Up time: 00:18:49 LDP discovery sources: Serial1/0, Src IP addr: 192.168.23.2 Addresses bound to peer LDP Ident: 192.168.12.2 192.168.0.2 192.168.23.2 R3#show ip vrf detail VRF VPN; default RD 100:100; default VPNID Interfaces: Fa0/0 Connected addresses are not in global routing table Export VPN route-target communities RT:100:100 Import VPN route-target communities RT:100:100 No import route-map No export route-map VRF label distribution protocol: not configured R3#show ip bgp vpnv4 all BGP table version is 11, local router ID is 192.168.0.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path Route Distinguisher: 100:100 (default for vrf VPN) *> 10.35.35.0/24 0.0.0.0 0 32768 ? *> 172.16.5.0/24 10.35.35.5 2 32768 ? R3#show ip route vrf VPN Routing Table: VPN Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route Gateway of last resort is not set 172.16.0.0/24 is subnetted, 1 subnets O 172.16.5.0 [110/2] via 10.35.35.5, 00:18:18, FastEthernet0/0 10.0.0.0/24 is subnetted, 1 subnets C 10.35.35.0 is directly connected, FastEthernet0/0 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
R1~R3のshowコマンドによって設定ミスがわかったので修正すると、正常にMPLS-VPNを通じてR4-R5間の通信ができるようになりました。
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待望のMPLS-VPNの仕組み解説セミナー、7/3(土)に開催!!
お申込、詳細は以下をご覧ください。
http://www.n-study.com/page/mpls-vpn.html
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