防火墙里的负载均衡是干嘛用的？

如下图所示，用户从两个运营商ISP 1和ISP 2处分别租用了链路Link 1和Link 2，这两条链路的路由器跳数、带宽和成本均相同，但Link 1的网络延迟小于Link 2。通过配置链路负载均衡，使Host访问Server时优先选择这两条链路中的最优链路。

图-1 出方向链路负载均衡基本组网配置组网图

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配置步骤

1. 配置接口IP地址

# 根据组网图中规划的信息，配置各接口的IP地址，具体配置步骤如下。

<Device> system-view

[Device] interface gigabitethernet 1/0/1

[Device-GigabitEthernet1/0/1] ip address 10.1.1.1 255.255.255.0

[Device-GigabitEthernet1/0/1] quit

请参考以上步骤配置其他接口的IP地址，具体配置步骤略。

2. 配置接口加入安全域。

# 请根据组网图中规划的信息，将接口加入对应的安全域，具体配置步骤如下。

[Device] security-zone name untrust

[Device-security-zone-Untrust] import interface gigabitethernet 1/0/1

[Device-security-zone-Untrust] import interface gigabitethernet 1/0/2

[Device-security-zone-Untrust] quit

[Device] security-zone name trust

[Device-security-zone-Trust] import interface gigabitethernet 1/0/3

[Device-security-zone-Trust] quit

3. 配置安全策略

配置安全策略放行Trust与Untrust安全域、Local与Untrust安全域之间的流量，用于用户访问外网服务器。

# 配置名称为lbrule1的安全策略规则，使用户可以访问外网服务器，具体配置步骤如下。

[Device] security-policy ip

[Device-security-policy-ip] rule name lbrule1

[Device-security-policy-ip-1-lbrule1] source-zone trust

[Device-security-policy-ip-1-lbrule1] destination-zone untrust

[Device-security-policy-ip-1-lbrule1] source-ip-subnet 192.168.1.0 255.255.255.0

[Device-security-policy-ip-1-lbrule1] action pass

[Device-security-policy-ip-1-lbrule1] quit

# 配置名称为lblocalout的安全策略规则，使Device可以向链路下一跳发送健康检测报文，具体配置步骤如下。

[Device-security-policy-ip] rule name lblocalout

[Device-security-policy-ip-2-lblocalout] source-zone local

[Device-security-policy-ip-2-lblocalout] destination-zone untrust

[Device-security-policy-ip-2-lblocalout] destination-ip-subnet 10.1.1.0 255.255.255.0

[Device-security-policy-ip-2-lblocalout] destination-ip-subnet 20.1.1.0 255.255.255.0

[Device-security-policy-ip-2-lblocalout] action pass

[Device-security-policy-ip-2-lblocalout] quit

[Device-security-policy-ip] quit

4. 配置链路组

# 创建ICMP类型的NQA模板t1，并配置每次探测结果发送机制。

[Device] nqa template icmp t1

[Device-nqatplt-icmp-t1] reaction trigger per-probe

[Device-nqatplt-icmp-t1] quit

# 指定缺省就近性探测方法为t1，并配置就近性计算的网络延迟权值为200。

[Device] loadbalance proximity

[Device-lb-proximity] match default probe t1

[Device-lb-proximity] rtt weight 200

[Device-lb-proximity] quit

# 创建链路组lg，开启就近性功能，关闭NAT功能。

[Device] loadbalance link-group lg

[Device-lb-lgroup-lg] proximity enable

[Device-lb-lgroup-lg] transparent enable

[Device-lb-lgroup-lg] quit

5. 配置链路

# 创建链路link1和link2，配置link1的下一跳IPv4地址为10.1.1.2，link2的下一跳IPv4地址为20.1.1.2，并加入链路组lg。

[Device] loadbalance link link1

[Device-lb-link-link1] router ip 10.1.1.2

[Device-lb-link-link1] link-group lg

[Device-lb-link-link1] quit

[Device] loadbalance link link2

[Device-lb-link-link2] router ip 20.1.1.2

[Device-lb-link-link2] link-group lg

[Device-lb-link-link2] quit

6. 配置虚服务器

# 创建LINK-IP类型的虚服务器vs，配置其VSIP为通配0.0.0.0/0，指定其缺省主用链路组为lg，并开启此虚服务器。

[Device] virtual-server vs type link-ip

[Device-vs-link-ip-vs] virtual ip address 0.0.0.0 0

[Device-vs-link-ip-vs] default link-group lg

[Device-vs-link-ip-vs] service enable

[Device-vs-link-ip-vs] quit

验证配置

# 显示所有链路的简要信息。

[Device] display loadbalance link brief

Link             Route IP             State        VPN instance   Link group

link1            10.1.1.2             Active                      lg

link2            20.1.1.2             Active                      lg

# 显示所有链路组的详细信息。

[Device] display loadbalance link-group

Link group: lg

  Description:

  Predictor: Round robin

  Proximity: Enabled

  NAT: Disabled

  SNAT pool:

  Failed action: Keep

  Active threshold: Disabled

  Slow-online: Disabled

  Selected link: Disabled

  Probe information:

    Probe success criteria: All

    Probe method:

    t1

  Total link: 2

  Active link: 2

  Link list:

  Name          State         VPN instance  Router IP            Weight Priority

  link1         Active                      10.1.1.2             100    4

  link2         Active                      20.1.1.2             100    4

# 显示所有虚服务器的详细信息。

[Device] display virtual-server

Virtual server: vs

  Description:

  Type: LINK-IP

  State: Active

  VPN instance:

  Virtual IPv4 address: 0.0.0.0/0

  Virtual IPv6 address: --

  Port: 0

  Primary link group: lg (in use)

  Backup link group:

  Sticky:

  LB policy:

  LB limit-policy:

  Connection limit: --

  Rate limit:

    Connections: --

    Bandwidth: --

    Inbound bandwidth: --

    Outbound bandwidth: --

  Connection synchronization: Disabled

  Sticky synchronization: Disabled

  Bandwidth busy protection: Disabled

  Interface bandwidth statistics: Disabled

  Route advertisement: Disabled

# 显示所有IPv4就近性表项的简要信息。

[Device] display loadbalance proximity ip

(*) - Real server object

Slot 1:

    IPv4 address/Mask length       Timeout     Best link

    ------------------------------------------------------------

    10.1.0.0/24                    50          link1

配置文件

#

interface GigabitEthernet1/0/1

 ip address 10.1.1.1 255.255.255.0

#

interface GigabitEthernet1/0/2

 ip address 20.1.1.1 255.255.255.0

#

interface GigabitEthernet1/0/3

 ip address 192.168.1.1 255.255.255.0

#

security-zone name Untrust

 import interface GigabitEthernet1/0/1

 import interface GigabitEthernet1/0/2

#

security-zone name Trust

 import interface GigabitEthernet1/0/3

#

security-policy ip

 rule 1 name lbrule1

  action pass

  source-zone trust

  destination-zone untrust

  source-ip-subnet 192.168.1.0 255.255.255.0

 rule 2 name lblocalout

  action pass

  source-zone local

  destination-zone untrust

  destination-ip-subnet 10.1.1.0 255.255.255.0

  destination-ip-subnet 20.1.1.0 255.255.255.0

#

nqa template icmp t1

 reaction trigger per-probe

#

loadbalance proximity

 rtt weight 200

 match default probe t1

#

loadbalance link-group lg

 proximity enable

 transparent enable

#

loadbalance link link1

 router ip 10.1.1.2

 link-group lg

#

loadbalance link link2

 router ip 20.1.1.2

 link-group lg

#

virtual-server vs type link-ip

 virtual ip address 0.0.0.0 0

 default link-group lg

 service enable

#