本檔案將說明簡易虛擬網路(EVN)功能,此功能是專為園區網路中提供簡單、易於設定的虛擬化機制而設計的。它利用當前技術,例如虛擬路由和轉發Lite(VRF-Lite)以及dot1q封裝,並且不引入任何新協定。
本文件沒有特定需求。
本檔案中的資訊是根據以下硬體和軟體版本:
本文中的資訊是根據特定實驗室環境內的裝置所建立。文中使用到的所有裝置皆從已清除(預設)的組態來啟動。如果您的網路正在作用,請確保您已瞭解任何指令可能造成的影響。
以下是EVN功能的概述:
使用本節中介紹的資訊配置EVN功能。
以下網路設定用於說明EVN配置和show命令:
以下是有關此設定的一些重要說明:
完成以下步驟即可設定EVN功能:
vrf definition [name]以下是有關此組態的一些重要說明:
vnet tag [2-4094]
!
address-family ipv4|ipv6
exit-address-family
!
vrf definition CUST-A在所有路由器上為這些VRF使用相同的VNET標籤。在CORE-4上,VRF COM不需要VNET標籤。目標是將VRF保留在CORE-4的本地位置,並配置洩漏和重新分發,以便從CUST-A和CUST-B訪問公共伺服器。
vnet tag 100
!
address-family ipv4
exit-address-family
vrf definition CUST-B
vnet tag 200
!
address-family ipv4
exit-address-family
CORE-1#show vnet counters
Maximum number of VNETs supported: 32
Current number of VNETs configured: 2
Current number of VNET trunk interfaces: 2
Current number of VNET subinterfaces: 4
Current number of VNET forwarding interfaces: 6
CORE-1#
interface GigabitEthernetx/x以下是有關此組態的一些重要說明:
vnet trunk
ip address x.x.x.x y.y.y.y
...
CORE-1#show run | s Ethernet0/0以下是派生的組態:
interface Ethernet0/0
vnet trunk
ip address 192.168.1.1 255.255.255.252
!
CORE-1#
CORE-1#show derived-config | s Ethernet0/0如圖所示,所有子介面都繼承主介面的IP地址。
interface Ethernet0/0
vnet trunk
ip address 192.168.1.1 255.255.255.252
Interface Ethernet0/0.100
description Subinterface for VNET CUST-A
encapsulation dot1Q 100
vrf forwarding CUST-A
ip address 192.168.1.1 255.255.255.252
interface Ethernet0/0.200
description Subinterface for VNET CUST-B
encapsulation dot1Q 200
vrf forwarding CUST-B
ip address 192.168.1.1 255.255.255.252
CORE-1#
interface GigabitEthernet x/x.y通過此設定,配置應用於CORE-1和CORE-4。以下是CORE-4的一個示例:
vrf forwarding [name]
ip address x.x.x.x y.y.y.y
...
interface Ethernet2/0
vrf forwarding CUST-A
ip address 10.1.2.1 255.255.255.0
!
interface Ethernet3/0
vrf forwarding CUST-B
ip address 10.2.2.1 255.255.255.0
!
interface Ethernet4/0
vrf forwarding COM
ip address 100.1.1.1 255.255.255.0
router ospf x vrf [name]
network x.x.x.x y.y.y.y area x
...
CORE-1#show run | s router os您可以進入路由情景模式,以檢視與特定VRF相關的資訊,而無需在每個命令中指定VRF:
router ospf 1 vrf CUST-A
network 10.1.1.0 0.0.0.255 area 0
network 192.168.1.0 0.0.0.255 area 0
router ospf 2 vrf CUST-B
network 10.2.1.0 0.0.0.255 area 0
network 192.168.1.0 0.0.0.255 area 0
CORE-1#
CORE-1#routing-context vrf CUST-A
CORE-1%CUST-A#
CORE-1%CUST-A#show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "ospf 1"
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Router ID 192.168.1.13
It is an area border router
Number of areas in this router is 1. 1 normal 0 stub 0 nssa
Maximum path: 4
Routing for Networks:
10.1.1.0 0.0.0.255 area 0
192.168.1.0 0.0.0.255 area 0
Routing Information Sources:
Gateway Distance Last Update
192.168.1.9 110 1d00h
192.168.1.14 110 1d00h
Distance: (default is 110)
CORE-1%CUST-A#
CORE-1%CUST-A#show ip os neighbor
Neighbor ID Pri State Dead Time Address Interface
192.168.1.14 1 FULL/DR 00:00:30 192.168.1.14 Ethernet1/0.100
192.168.1.5 1 FULL/BDR 00:00:37 192.168.1.2 Ethernet0/0.100
10.1.1.2 1 FULL/BDR 00:00:33 10.1.1.2 Ethernet2/0
CORE-1%CUST-A#
CORE-1%CUST-A#show ip route 10.1.2.0
Routing Table: CUST-A
Routing entry for 10.1.2.0/24
Known via "ospf 1", distance 110, metric 30, type intra area
Last update from 192.168.1.2 on Ethernet0/0.100, 1d00h ago
Routing Descriptor Blocks:
* 192.168.1.14, from 192.168.1.9, 1d00h ago, via Ethernet1/0.100
Route metric is 30, traffic share count is 1
192.168.1.2, from 192.168.1.9, 1d00h ago, via Ethernet0/0.100
Route metric is 30, traffic share count is 1
CORE-1%CUST-A#
CORE-1%CUST-A#routing-context vrf CUST-B
CORE-1%CUST-B#
CORE-1%CUST-B#show ip route 10.2.2.0
Routing Table: CUST-B
Routing entry for 10.2.2.0/24
Known via "ospf 2", distance 110, metric 30, type intra area
Last update from 192.168.1.2 on Ethernet0/0.200, 1d00h ago
Routing Descriptor Blocks:
* 192.168.1.14, from 192.168.1.6, 1d00h ago, via Ethernet1/0.200
Route metric is 30, traffic share count is 1
192.168.1.2, from 192.168.1.6, 1d00h ago, via Ethernet0/0.200
Route metric is 30, traffic share count is 1
CORE-1%CUST-B#
CORE-1%CUST-B#exit
CORE-1#
CORE-1#
vrf definition VRF-X以下是有關此組態的一些重要說明:
address-family ipv4|ipv6
route-replicate from vrf VRF-Y unicast|multicast
[route-origin] [route-map [name]]
vrf definition CUST-A此時,複製的路由不會在內部網關協定(IGP)中傳播,因此只有CE-A-2和CE-B-2可以訪問COM服務(100.1.1.100),而不是CE-A-1和CE-B-1。
address-family ipv4
route-replicate from vrf COM unicast connected
!
vrf definition CUST-B
address-family ipv4
route-replicate from vrf COM unicast connected
!
vrf definition COM
address-family ipv4
route-replicate from vrf CUST-A unicast ospf 1 route-map USERS
route-replicate from vrf CUST-B unicast ospf 2 route-map USERS
!
route-map USERS permit 10
match ip address prefix-list USER-SUBNETS
!
ip prefix-list USER-SUBNETS seq 5 permit 10.0.0.0/8 le 32
CORE-4#show ip route vrf CUST-A
Routing Table: COM
Codes: L - local, 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, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override
...
10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks
O 10.1.1.0/24 [110/30] via 192.168.1.10, 3d19h, Ethernet1/0.100
[110/30] via 192.168.1.5, 3d19h, Ethernet0/0.100
100.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C + 100.1.1.0/24 is directly connected (COM), Ethernet4/0
CORE-4#show ip route vrf CUST-B
... 10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks
O 10.2.1.0/24 [110/30] via 192.168.1.10, 1d00h, Ethernet1/0.200
[110/30] via 192.168.1.5, 1d00h, Ethernet0/0.200
100.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C + 100.1.1.0/24 is directly connected (COM), Ethernet4/0
CORE-4#show ip route vrf COM
...
10.0.0.0/24 is subnetted, 2 subnets
O + 10.1.1.0 [110/30] via 192.168.1.10 (CUST-A), 3d19h, Ethernet1/0.100
[110/30] via 192.168.1.5 (CUST-A), 3d19h, Ethernet0/0.100
O + 10.2.1.0 [110/30] via 192.168.1.10 (CUST-B), 1d00h, Ethernet1/0.200
[110/30] via 192.168.1.5 (CUST-B), 1d00h, Ethernet0/0.200
100.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 100.1.1.0/24 is directly connected, Ethernet4/0
vrf definition VRF-X
address-family ipv4
route-replicate from vrf >global unicast|multicast [route-origin]
[route-map [name]]
exit-address-family
!
exit
!
global-address-family ipv4 unicast
route-replicate from vrf [vrf-name] unicast|multicast [route-origin]
[route-map [name]]
router ospf x vrf VRF-X從VRF-Y洩漏的路由在VRF-X中運行的OSPF進程中重新分配。以下是CORE-4的一個示例:
redistribute vrf VRF-Y [route-origin] [route-map [name]]
router ospf 1 vrf CUST-A本例中不需要路由對映,因為VRF COM中只有一個連線的路由。現在可從CE-A-1和CE-B-1訪問COM服務(100.1.1.100):
redistribute vrf COM connected subnets route-map CON-2-OSPF
!
route-map CON-2-OSPF permit 10
match ip address prefix-list COM
!
ip prefix-list COM seq 5 permit 100.1.1.0/24
CE-A-1#ping 100.1.1.100
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 100.1.1.100, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
CE-A-1#
CE-B-1#ping 100.1.1.100
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 100.1.1.100, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
CE-B-1#
本節提供的資訊可用於調整VNET中繼。
預設情況下,所有VNET中繼上都允許配置有VNET標籤的所有VRF。中繼清單允許您指定VNET中繼上的授權VRF清單:
vrf list [list-name]
member [vrf-name]
!
interface GigabitEthernetx/x
vnet trunk list [list-name]
例如,CORE-1在CORE-1和CORE-2之間的VNET中繼上為VRF CUST-B進行了調整:
vrf list TEST
member CUST-A
!
interface ethernet0/0
vnet trunk list TEST
如圖所示,VRF CUST-B的OSPF對等通過中繼斷開:
%OSPF-5-ADJCHG: Process 2, Nbr 192.168.1.2 on Ethernet0/0.200 from FULL to DOWN,
Neighbor Down: Interface down or detached
VRF CUST-B的子介面被刪除:
CORE-1#show derived-config | b Ethernet0/0
interface Ethernet0/0
vnet trunk list TEST
ip address 192.168.1.1 255.255.255.252
!
interface Ethernet0/0.100
description Subinterface for VNET CUST-A
encapsulation dot1Q 100
vrf forwarding CUST-A
ip address 192.168.1.1 255.255.255.252
!
預設情況下,dot1q子介面繼承物理介面的引數,以便所有VRF的子介面具有相同的屬性(如成本和身份驗證)。 可以調整每個VNET標籤的中繼引數:
interface GigaEthernetx/x
vnet trunk
vnet name VRF-X
ip ospf cost 100
vnet name VRF-Y
ip ospf cost 15
您可以調整以下引數:
CORE-1(config-if-vnet)#?
Interface VNET instance override configuration commands:
bandwidth Set bandwidth informational parameter
default Set a command to its defaults
delay Specify interface throughput delay
exit-if-vnet Exit from VNET submode
ip Interface VNET submode Internet Protocol config commands
no Negate a command or set its defaults
vnet Configure protocol-independent VNET interface options
CORE-1(config-if-vnet)#
CORE-1(config-if-vnet)#ip ?
authentication authentication subcommands
bandwidth-percent Set EIGRP bandwidth limit
dampening-change Percent interface metric must change to cause update
dampening-interval Time in seconds to check interface metrics
hello-interval Configures EIGRP-IPv4 hello interval
hold-time Configures EIGRP-IPv4 hold time
igmp IGMP interface commands
mfib Interface Specific MFIB Control
multicast IP multicast interface commands
next-hop-self Configures EIGRP-IPv4 next-hop-self
ospf OSPF interface commands
pim PIM interface commands
split-horizon Perform split horizon
summary-address Perform address summarization
verify Enable per packet validation
CORE-1(config-if-vnet)#ip
在本例中,CORE-1的每個VRF的OSPF開銷已更改,因此CORE-2路徑用於CUST-A,CORE-3路徑用於CUST-B(預設開銷為10):
interface Ethernet0/0
vnet name CUST-A
ip ospf cost 8
!
vnet name CUST-B
ip ospf cost 12
!
CORE-1#show ip route vrf CUST-A 10.1.2.0
Routing Table: CUST-A
Routing entry for 10.1.2.0/24
Known via "ospf 1", distance 110, metric 28, type intra area
Last update from 192.168.1.2 on Ethernet0/0.100, 00:05:42 ago
Routing Descriptor Blocks:
* 192.168.1.2, from 192.168.1.9, 00:05:42 ago, via Ethernet0/0.100
Route metric is 28, traffic share count is 1
CORE-1#
CORE-1#show ip route vrf CUST-B 10.2.2.0
Routing Table: CUST-B
Routing entry for 10.2.2.0/24
Known via "ospf 2", distance 110, metric 30, type intra area
Last update from 192.168.1.14 on Ethernet1/0.200, 00:07:03 ago
Routing Descriptor Blocks:
* 192.168.1.14, from 192.168.1.6, 1d18h ago, via Ethernet1/0.200
Route metric is 30, traffic share count is 1
CORE-1#
預設情況下,在VRF定義中定義的VNET標籤用於所有中繼。但是,每個中繼可以使用不同的VNET標籤。
此範例介紹這樣一種情況:您連線到不支援EVN的裝置,將VRF-Lite與手動中繼一起使用,並且全域VNET標籤由另一個VLAN使用:
通過此設定,用於CUST-A的CORE-1和CORE-2之間的中繼上使用的VNET標籤從100更改為101:
interface Ethernet0/0
vnet name CUST-A
vnet tag 101
在CORE-1上發生此更改後,將建立一個新的子介面:
CORE-1#show derived-config | b Ethernet0/0
interface Ethernet0/0
vnet trunk
ip address 192.168.1.1 255.255.255.252
!
interface Ethernet0/0.101
description Subinterface for VNET CUST-A
encapsulation dot1Q 101
vrf forwarding CUST-A
ip address 192.168.1.1 255.255.255.252
!
interface Ethernet0/0.200
description Subinterface for VNET CUST-B
encapsulation dot1Q 200
vrf forwarding CUST-B
ip address 192.168.1.1 255.255.255.252
如果此更改僅在一端發生,則相關VRF中的連線會丟失,並且OSPF會關閉:
%OSPF-5-ADJCHG: Process 1, Nbr 192.168.1.5 on Ethernet0/0.101 from FULL to DOWN,
Neighbor Down: Dead timer expired
在CORE-2上使用相同的VNET標籤後,連線會恢復,並且在該中繼上使用dot1q標籤101,而在CORE-1到CORE-3中繼上仍使用100:
%OSPF-5-ADJCHG: Process 1, Nbr 192.168.1.5 on Ethernet0/0.101 from LOADING to
FULL, Loading Done
目前沒有適用於此組態的驗證程序。
目前尚無適用於此組態的具體疑難排解資訊。
修訂 | 發佈日期 | 意見 |
---|---|---|
1.0 |
04-Aug-2014 |
初始版本 |