组网要求:PC1和PC2通过4台三层交换机相连,从拓扑图中可以看出,数据从PC1到PC2有两条路径可以到达,分别是PC1-SW1-SW2-SW4-PC2和PC1-SW3-SW4-PC2,OSPF网络中有四台交换机,同属于区域0。要求配置负载分担,使得Sw1流量,可以分别通过Sw2和Sw3送到Sw4。
一、本节主要知识点:
OSPF负载分担:等价负载分担ECMP(Equal-Cost Multiple Path),是指在两个网络节点之间同时存在多条路径时,节点间的流量在多条路径上平均分摊。负载分担的作用是减轻每条路径的流量压力,增强网络健壮性。当到达同一目的地存在同一路由协议发现的多条路由时,且这几条路由的开销值也相同,那么就满足负载分担的条件。当实现负载分担时,路由器根据五元组(源地址、目的地址、源端口、目的端口、协议)进行转发,当五元组相同时,路由器总是选择与上一次相同的下一跳地址发送报文。当五元组不同时,路由器会选取相对空闲的路径进行转发。在OSPF网络中,有时候两个网元之间会存在多条等价路径,而单条路径又很难承担全部的业务流量,此时用户一般希望多条路径平均分摊所有的业务流量,这样既能提高网络的可靠性,又能提高资源的利用率,这种情况下可以考虑配置OSPF负载分担。
说明:请确保该场景下互联接口的STP处于未使能状态。因为在使能STP的环形网络中,如果用交换机的VLANIF接口构建三层网络,会导致某个端口被阻塞,从而导致三层业务不能正常运行。
二、配置思路:
1、创建VLAN并配置各接口所属VLAN,配置各VLANIF接口的IP地址。
2、在各交换机上配置OSPF基本功能,实现OSPF网络的基本互通。
3、在SwitchA配置负载分担,实现负载均衡的目的。
三、IP设置:
1、SW1:
VLANif10:192.168.10.254/24 ,vlan10
VLANif20:192.168.20.1/24 ,vlan20
VLANif30:192.168.30.1/24 ,vlan30
PC1:192.168.10.1/24
2、SW2:
VLANif20:192.168.20.2/24 ,vlan20
VLANif50:192.168.50.1/24 ,vlan50
3、SW3:
VLANif30:192.168.30.2/24 ,vlan30
VLANif40:192.168.40.1/24 ,vlan 50
4、SW4:
VLANif40:192.168.40.2/24 ,vlan40
VLANif50:192.168.50.2/24 ,vlan50
VLANif60:192.168.60.254/24 ,vlan60
PC2:192.168.60.1/24
四、实际操作视频:
五、SW1交换机的主要配置文件:
#
sysname SW1
#
vlan batch 10 20 30
#
interface Vlanif10
ip address 192.168.10.254 255.255.255.0
#
interface Vlanif20
ip address 192.168.20.1 255.255.255.0
#
interface Vlanif30
ip address 192.168.30.1 255.255.255.0
#
interface MEth0/0/1
#
interface GigabitEthernet0/0/1
port link-type access
port default vlan 10
#
interface GigabitEthernet0/0/2
port link-type trunk
port trunk allow-pass vlan 2 to 4094
#
interface GigabitEthernet0/0/3
port link-type trunk
port trunk allow-pass vlan 2 to 4094
#
ospf 1
area 0.0.0.0
network 192.168.10.0 0.0.0.255
network 192.168.20.0 0.0.0.255
network 192.168.30.0 0.0.0.255
#
return
六、SW2交换机的主要配置文件:
#
sysname SW2
#
vlan batch 20 50
#
interface Vlanif20
ip address 192.168.20.2 255.255.255.0
#
interface Vlanif50
ip address 192.168.50.1 255.255.255.0
#
interface MEth0/0/1
#
interface GigabitEthernet0/0/1
port link-type trunk
port trunk allow-pass vlan 2 to 4094
#
interface GigabitEthernet0/0/2
port link-type trunk
port trunk allow-pass vlan 2 to 4094
#
ospf 1
area 0.0.0.0
network 192.168.20.0 0.0.0.255
network 192.168.50.0 0.0.0.255
#
return
七、SW3交换机的主要配置文件:
#
sysname SW3
#
vlan batch 30 40
#
stp disable //关闭stp破环协议,否则三层业务不能正常运行
#
interface Vlanif30
ip address 192.168.30.2 255.255.255.0
#
interface Vlanif40
ip address 192.168.40.1 255.255.255.0
#
interface MEth0/0/1
#
interface GigabitEthernet0/0/1
port link-type trunk
port trunk allow-pass vlan 2 to 4094
#
interface GigabitEthernet0/0/2
port link-type trunk
port trunk allow-pass vlan 2 to 4094
#
ospf 1
area 0.0.0.0
network 192.168.30.0 0.0.0.255
network 192.168.40.0 0.0.0.255
#
return
八、SW4交换机的主要配置文件:
#
sysname SW4
#
vlan batch 40 50 60
#
interface Vlanif40
ip address 192.168.40.2 255.255.255.0
#
interface Vlanif50
ip address 192.168.50.2 255.255.255.0
#
interface Vlanif60
ip address 192.168.60.254 255.255.255.0
#
interface MEth0/0/1
#
interface GigabitEthernet0/0/1
port link-type trunk
port trunk allow-pass vlan 2 to 4094
#
interface GigabitEthernet0/0/2
port link-type trunk
port trunk allow-pass vlan 2 to 4094
#
interface GigabitEthernet0/0/3
port link-type access
port default vlan 60
#
ospf 1
// 如果不希望Sw2和Sw3形成负载分担,可以配置等价路由优先级,指定下一跳。使用:nexthop 192.168.20.2 weight 1 命令,(1-254)数值越小优先级越高。
area 0.0.0.0
network 192.168.40.0 0.0.0.255
network 192.168.50.0 0.0.0.255
network 192.168.60.0 0.0.0.255
#
return
九、验证配置结果:
1、查看SW1的IP路由表。
[SW1]disp ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 11 Routes : 12
Destination/Mask Proto Pre Cost Flags NextHop Interface
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
192.168.10.0/24 Direct 0 0 D 192.168.10.254 Vlanif10
192.168.10.254/32 Direct 0 0 D 127.0.0.1 Vlanif10
192.168.20.0/24 Direct 0 0 D 192.168.20.1 Vlanif20
192.168.20.1/32 Direct 0 0 D 127.0.0.1 Vlanif20
192.168.30.0/24 Direct 0 0 D 192.168.30.1 Vlanif30
192.168.30.1/32 Direct 0 0 D 127.0.0.1 Vlanif30
192.168.40.0/24 OSPF 10 2 D 192.168.30.2 Vlanif30
192.168.50.0/24 OSPF 10 2 D 192.168.20.2 Vlanif20
192.168.60.0/24 OSPF 10 3 D 192.168.20.2 Vlanif20
OSPF 10 3 D 192.168.30.2 Vlanif30
从路由表可以看出,Sw1到192.168.60.0有两个下一跳192.168.20.2(Sw2)和192.168.30.2(Sw3)均成为有效路由。
2、查看SW1到192.168.60.0 ip路由表详情。
[SW1]disp ip routing-table 192.168.60.0 ver
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Table : Public
Summary Count : 2
Destination: 192.168.60.0/24
Protocol: OSPF Process ID: 1
Preference: 10 Cost: 3
NextHop: 192.168.20.2 Neighbour: 0.0.0.0
State: Active AdvAge: 00h10m58s
Tag: 0 Priority: low
Label: NULL QoSInfo: 0x0
IndirectID: 0x0
RelayNextHop: 0.0.0.0 Interface: Vlanif20
TunnelID: 0x0 Flags: D
Destination: 192.168.60.0/24
Protocol: OSPF Process ID: 1
Preference: 10 Cost: 3
NextHop: 192.168.30.2 Neighbour: 0.0.0.0
State: Active Adv Age: 00h05m36s
Tag: 0 Priority: low
Label: NULL QoSInfo: 0x0
IndirectID: 0x0
RelayNextHop: 0.0.0.0 Interface: Vlanif30
TunnelID: 0x0 Flags: D
2、可以看出Sw1到Sw4(192.168.60.0)网络有2条活动路由。
3、在PC1使用ping命令验证连通性。
PC>ping 192.168.60.1
Ping 192.168.60.1: 32 data bytes, Press Ctrl_C to break
From 192.168.60.1: bytes=32 seq=1 ttl=125 time=94 ms
From 192.168.60.1: bytes=32 seq=2 ttl=125 time=93 ms
From 192.168.60.1: bytes=32 seq=3 ttl=125 time=79 ms
From 192.168.60.1: bytes=32 seq=4 ttl=125 time=62 ms
From 192.168.60.1: bytes=32 seq=5 ttl=125 time=63 ms
领取专属 10元无门槛券
私享最新 技术干货