原理
1. 网络负载平衡,使用Windows Network Load Balance. 参考微软技术文档,http://www.microsoft.com/china/technet/prodtechnol/windowsserver2003/technologies/clustering/nlbbp.mspx网络负载平衡:Windows 2000 和 Windows Server 2003 的配置最佳实践
2. 互为备份,实现方法
- 两台ISA各自周期限性的检查自己的Default Gateway,通过ICMP (PING)来确定物理链路是否正常工作。
- 当发现ICMP 结果失败,停止本机的NLB服务,这样双节点的NLB 自动Failover 到另一个节点
- 写了一个服务程序来实现此功能,附源代码及工程文件。
网络拓朴图如下
DG : Default Gateway NLB: Network Load Balance
具体实现
因为实验环境有限,修改网络拓朴图如下,道理相信大家都明白的。
1. Windows 2003 Server (Enterprise Edition) x 2 或 Windows 2000 Advanced Server x 2. 只有Windows 2000 Advanced Server/Windows 2003 Enterprise Edition才支持Network Load Balancing
2. 安装ISA Server 2000 (Standard Edition), Standalone, 集成模式,双网卡
安装次序,
- All Windows Critical Updates
- ISA Server 2000 Service Pack 1
- ISA Server 2000 Feature Pack 1
- ISA Server 2000 Service Pack 2
原理1 网络配置 部分
ISA Server 1 (ISA1)
Windows IP Configuration
Host Name . . . . . . . . . . . . : ISA1 Primary Dns Suffix . . . . . . . : vnet.net Node Type . . . . . . . . . . . . : Unknown IP Routing Enabled. . . . . . . . : Yes WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : vnet.net
Ethernet adapter InternalNIC:
Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Intel 21140-Based PCI Fast Ethernet Adapter (Generic) #2 Physical Address. . . . . . . . . : 02-BF-0A-00-00-03 DHCP Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : 10.0.0.3 Subnet Mask . . . . . . . . . . . : 255.0.0.0 IP Address. . . . . . . . . . . . : 10.0.0.1 Subnet Mask . . . . . . . . . . . : 255.0.0.0 Default Gateway . . . . . . . . . : DNS Servers . . . . . . . . . . . : 10.0.0.1 10.0.0.2
Ethernet adapter ExternalNIC:
Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Intel 21140-Based PCI Fast Ethernet Adapter (Generic) Physical Address. . . . . . . . . : 00-03-FF-C0-68-CD DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IP Address. . . . . . . . . . . . : 192.168.0.252 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.0.230 DHCP Server . . . . . . . . . . . : 192.168.0.230 DNS Servers . . . . . . . . . . . : 202.96.209.5 202.96.209.133 Lease Obtained. . . . . . . . . . : Saturday, August 14, 2004 4:00:02 PM Lease Expires . . . . . . . . . . : Saturday, August 14, 2004 5:00:02 PM
网络负载平衡配置图
ISA Server 2 (ISA2)
Windows IP Configuration
Host Name . . . . . . . . . . . . : ISA2 Primary Dns Suffix . . . . . . . : vnet.net Node Type . . . . . . . . . . . . : Unknown IP Routing Enabled. . . . . . . . : Yes WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : vnet.net
Ethernet adapter ExternalNIC:
Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Intel 21140-Based PCI Fast Ethernet Adapter (Generic) Physical Address. . . . . . . . . : 00-03-FF-C1-68-CD DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IP Address. . . . . . . . . . . . : 192.168.0.251 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.0.230 DHCP Server . . . . . . . . . . . : 192.168.0.230 DNS Servers . . . . . . . . . . . : 202.96.209.5 202.96.209.133 Lease Obtained. . . . . . . . . . : Saturday, August 14, 2004 4:00:14 PM Lease Expires . . . . . . . . . . : Saturday, August 14, 2004 5:00:14 PM
Ethernet adapter InternalNIC:
Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Intel 21140-Based PCI Fast Ethernet Adapter (Generic) #2 Physical Address. . . . . . . . . : 02-BF-0A-00-00-03 DHCP Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : 10.0.0.3 Subnet Mask . . . . . . . . . . . : 255.0.0.0 IP Address. . . . . . . . . . . . : 10.0.0.2 Subnet Mask . . . . . . . . . . . : 255.0.0.0 Default Gateway . . . . . . . . . : DNS Servers . . . . . . . . . . . : 10.0.0.1 10.0.0.2
网络负载平衡配置 图
完成上述配置后,要对网络负载平衡配置进行复核,确保其能正常工作。请在任一ISA上运行wlbs query。
如出现下图所示的结果,一切正常。如果最后一行只有1或只有2,NLB工作不正常。这边不展开讨论NLB的问题。
C:\Documents and Settings\Administrator>wlbs query WLBS Cluster Control Utility V2.4 (c) 1997-2003 Microsoft Corporation. Cluster 10.0.0.3 Host 2 has entered a converging state 6 time(s) since joining the cluster and the last convergence completed at approximately: 8/14/2004 4:23:15 PM Host 2 converged with the following host(s) as part of the cluster: 1, 2
继续在ISA1/ISA2上建立相应的协议规则(Protocol Rule/Site and Content Rule),客户端就可以使用10.0.0.3的地址访问Internet,
做得更加完美的话,可以在DNS加入一条A记录ISA -> 10.0.0.3
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