はじめての OTV (Overlay Transport Virtualization)
OTV を使うと L2 延伸を行うことが出来ます。例えば、離れたデータセンター間で仮想マシンを vMotion した際等に利用出来ます。L2延伸だけなら L2TP でも可能ですが、L2TP ではループする可能性があります。対して OTV はマルチパス機能やループフリーである、という性質を持っています。今回はシンプルな構成で OTV を試してみます。
構成
以下の構成で検証します。
![file](01.png)
DC1 と DC2 という異なるデータセンターの OTV ルータ間でユニキャストを使った OTV 設定をしていますので、DC1 と DC2 の LAN 内が同じ 192.168.200.0/24 (VLAN200) というネットワークになっています。各ルータの OS は以下の通りです。
Hostname |
OS |
DC1-OTV |
IOS-XE 03.17.00 |
DC2-OTV |
IOS-XE 03.17.00 |
Core |
15.6(2)T |
DC1-Host |
15.6(2)T |
DC2-Host |
15.6(2)T |
コンフィグ
Host と Core はインターフェイスにアドレスを割り当てているだけで、その他は特に何も設定していません。
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35 | DC1-OTV
hostname DC1-OTV
!
otv site bridge-domain 100
otv isis hello-interval 3
!
otv site-identifier 0000.0000.0001
!
interface Overlay0
no ip address
no shutdown
otv join-interface GigabitEthernet2
otv adjacency-server unicast-only
otv isis hello-interval 3
service instance 200 ethernet
encapsulation dot1q 200
bridge-domain 200
!
interface GigabitEthernet2
ip address 10.0.1.1 255.255.255.0
no shutdown
!
interface GigabitEthernet3
no ip address
no shutdown
service instance 100 ethernet
encapsulation dot1q 100
bridge-domain 100
service instance 200 ethernet
encapsulation dot1q 200
bridge-domain 200
!
ip route 10.0.2.0 255.255.255.0 10.0.1.254
!
end
|
DC2-OTV
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47 | hostname DC2-OTV
!
otv site bridge-domain 100
otv isis hello-interval 3
!
otv site-identifier 0000.0000.0002
!
interface Overlay0
no ip address
no shutdown
otv join-interface GigabitEthernet2
otv use-adjacency-server 10.0.1.1 unicast-only
otv adjacency-server unicast-only
otv isis hello-interval 3
service instance 200 ethernet
encapsulation dot1q 200
bridge-domain 200
!
interface GigabitEthernet2
ip address 10.0.2.2 255.255.255.0
no shutdown
!
interface GigabitEthernet3
no ip address
no shutdown
service instance 100 ethernet
encapsulation dot1q 100
bridge-domain 100
service instance 200 ethernet
encapsulation dot1q 200
bridge-domain 200
!
ip route 10.0.1.0 255.255.255.0 10.0.2.254
!
end
Core
hostname Core
!
interface GigabitEthernet0/1
ip address 10.0.1.254 255.255.255.0
no shutdown
!
interface GigabitEthernet0/2
ip address 10.0.2.254 255.255.255.0
no shutdown
!
end
|
DC1-Host
| hostname DC1-Host
!
interface GigabitEthernet0/1
no ip address
no shutdown
!
interface GigabitEthernet0/1.200
encapsulation dot1Q 200
ip address 192.168.200.11 255.255.255.0
!
end
|
DC2-Host
| hostname DC2-Host
!
interface GigabitEthernet0/1
no ip address
no shutdown
!
interface GigabitEthernet0/1.200
encapsulation dot1Q 200
ip address 192.168.200.22 255.255.255.0
!
end
|
状態確認
DC1-Host から DC2-Host へ Ping を実行
| DC1-Host# ping 192.168.200.22
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.200.22, timeout is 2 seconds:
..!!!
Success rate is 60 percent (3/5), round-trip min/avg/max = 9/10/12 ms
|
| DC1-Host# show ip arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 192.168.200.11 - fa16.3e2f.8da1 ARPA GigabitEthernet0/1.200
Internet 192.168.200.22 7 fa16.3ee5.aae6 ARPA GigabitEthernet0/1.20
|
DC1-OTV の状態
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19 | DC1-OTV# show otv
Overlay Interface Overlay0
VPN name : None
VPN ID : 1
State : UP
Fwd-capable : Yes
Fwd-ready : Yes
AED-Server : Yes
Backup AED-Server : No
AED Capable : Yes
Join interface(s) : GigabitEthernet2
Join IPv4 address : 10.0.1.1
Tunnel interface(s) : Tunnel0
Encapsulation format : GRE/IPv4
Site Bridge-Domain : 100
Capability : Unicast-only
Is Adjacency Server : Yes
Adj Server Configured : No
Prim/Sec Adj Svr(s) : None
|
| DC1-OTV# show otv site
Site Adjacency Information (Site Bridge-Domain: 100)
Overlay0 Site-Local Adjacencies (Count: 1)
Hostname System ID Last Change Ordinal AED Enabled Status
* DC1-OTV 001E.7A3B.C900 01:43:25 0 site overlay
|
| DC1-OTV# show otv vlan
Key: SI - Service Instance, NA - Non AED, NFC - Not Forward Capable.
Overlay 0 VLAN Configuration Information
Inst VLAN BD Auth ED State Site If(s)
0 200 200 *DC1-OTV active Gi3:SI200
Total VLAN(s): 1
|
| DC1-OTV# show otv adjacency
Overlay Adjacency Database for overlay 0
Hostname System-ID Dest Addr Site-ID Up Time State
DC2-OTV 001e.e681.fd00 10.0.2.2 0000.0000.0002 01:41:38 UP
|
| DC1-OTV# show otv arp-nd-cache
Overlay0 ARP/ND L3->L2 Address Mapping Cache
BD MAC Layer-3 Address Age (HH:MM:SS) Local/Remote
200 fa16.3ee5.aae6 192.168.200.22 00:00:34 Remote
|
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16 | DC1-OTV# show otv route
Codes: BD - Bridge-Domain, AD - Admin-Distance,
SI - Service Instance, * - Backup Route
OTV Unicast MAC Routing Table for Overlay0
Inst VLAN BD MAC Address AD Owner Next Hops(s)
----------------------------------------------------------
0 200 200 fa16.3e2f.8da1 40 BD Eng Gi3:SI200
0 200 200 fa16.3ee5.aae6 50 ISIS DC2-OTV
2 unicast routes displayed in Overlay0
----------------------------------------------------------
2 Total Unicast Routes Displayed
|
DC2-OTV の状態
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26 | DC2-OTV# show otv
Overlay Interface Overlay0
VPN name : None
VPN ID : 1
State : UP
Fwd-capable : Yes
Fwd-ready : Yes
AED-Server : Yes
Backup AED-Server : No
AED Capable : Yes
Join interface(s) : GigabitEthernet2
Join IPv4 address : 10.0.2.2
Tunnel interface(s) : Tunnel0
Encapsulation format : GRE/IPv4
Site Bridge-Domain : 100
Capability : Unicast-only
Is Adjacency Server : Yes
Adj Server Configured : Yes
Prim/Sec Adj Svr(s) : 10.0.1.1
DC2-OTV# show otv site
Site Adjacency Information (Site Bridge-Domain: 100)
Overlay0 Site-Local Adjacencies (Count: 1)
Hostname System ID Last Change Ordinal AED Enabled Status
* DC2-OTV 001E.E681.FD00 01:46:12 0 site overlay
|
| DC2-OTV# show otv vlan
Key: SI - Service Instance, NA - Non AED, NFC - Not Forward Capable.
Overlay 0 VLAN Configuration Information
Inst VLAN BD Auth ED State Site If(s)
0 200 200 *DC2-OTV active Gi3:SI200
Total VLAN(s): 1
|
| DC2-OTV# show otv adjacency
Overlay Adjacency Database for overlay 0
Hostname System-ID Dest Addr Site-ID Up Time State
DC1-OTV 001e.7a3b.c900 10.0.1.1 0000.0000.0001 01:46:54 UP
|
| DC2-OTV# show otv arp-nd-cache
Overlay0 ARP/ND L3->L2 Address Mapping Cache
BD MAC Layer-3 Address Age (HH:MM:SS) Local/Remote
200 fa16.3e2f.8da1 192.168.200.11 00:04:58 Remote
|
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16 | DC2-OTV# show otv route
Codes: BD - Bridge-Domain, AD - Admin-Distance,
SI - Service Instance, * - Backup Route
OTV Unicast MAC Routing Table for Overlay0
Inst VLAN BD MAC Address AD Owner Next Hops(s)
----------------------------------------------------------
0 200 200 fa16.3e2f.8da1 50 ISIS DC1-OTV
0 200 200 fa16.3ee5.aae6 40 BD Eng Gi3:SI200
2 unicast routes displayed in Overlay0
----------------------------------------------------------
2 Total Unicast Routes Displayed
|
DC2-Host での状態確認
| DC2-Host# show ip arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 192.168.200.11 7 fa16.3e2f.8da1 ARPA GigabitEthernet0/1.200
Internet 192.168.200.22 - fa16.3ee5.aae6 ARPA GigabitEthernet0/1.20
|
参考 URL