使用 PXE 的 DHCP 故障转移

Question

经过多次实验后，我找到了答案：事实证明，池内的访问控制语句的顺序很重要。

以下是我原始帖子中的类定义的重复：

class "dhcp" {
      match if exists dhcp-message-type;
}
class "pxe" {
      match if substring (option vendor-class-identifier, 0, 9) = "PXEClient";
}

这是subnet在我的主 DHCP 服务器上有效的定义。这与我原始帖子中的配置的主要区别在于range语句的顺序与任何allow或deny语句的顺序不同，并且我"pxe"首先定义池。原始故障转移行保持不变。

subnet 10.4.0.0 netmask 255.255.0.0 {
    default-lease-time 86400; # one day (in seconds)
    option subnet-mask 255.255.0.0;
    option broadcast-address 10.4.255.255;
    option routers 10.4.0.1;
    option domain-name-servers 10.4.7.7, 10.4.7.29; 
    option domain-name "company.example.com";
    option time-offset -18000; # Eastern Standard Time
    option ntp-servers 10.4.7.105, 10.4.7.7, 10.4.7.29;
    next-server 10.4.7.9;    # On which system the bootp filename is located.

    if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
        if option architecture-type =  00:07 {
           filename "uefi/grubx64.efi"; # The file to load for EFI systems.
        }
        else {
           filename "pxelinux/pxelinux.0"; # The file to load via bootp for BIOS systems.
        }
    }

    # A separate pool for PXE services.
    pool {
         range dynamic-bootp 10.4.45.251 10.4.45.255; # DHCP pool on private network
         allow dynamic bootp clients;
         allow members of "pxe";
    }

    # The "regular" DHCP pool.
    pool {
         failover peer "dhcp-failover";
         range 10.4.45.1 10.4.45.250; # DHCP pool on private network
         deny dynamic bootp clients;
         deny members of "pxe";
    }
}

以下是subnet我的辅助 DHCP 服务器配置中修改后的行，尽管这些更改可能并不重要：

subnet 10.4.0.0 netmask 255.255.0.0 {
    default-lease-time 86400; # one day (in seconds)
    option subnet-mask 255.255.0.0;
    option broadcast-address 10.4.255.255;
    option routers 10.4.0.1;
    option domain-name-servers 10.4.7.7, 10.4.7.29; 
    option domain-name "company.example.com";
    option time-offset -18000; # Eastern Standard Time
    option ntp-servers 10.4.7.105, 10.4.7.7, 10.4.7.29;

    # Note that there are a few IP addresses in the range of the primary
    # server that are not included here. This is for PXE, which is
    # not handled by the secondary server.
    pool {
         failover peer "dhcp-failover";
         deny dynamic bootp clients;     
         range 10.4.45.1 10.4.45.250; # DCHP pool on private network
    }
}

我现在有一个设置，既有 DHCP 故障转移，也有 PXE 启动，用于安装/修复操作系统，可同时容纳 BIOS 和 EFI 系统。我希望其他人会发现上面的内容很有用！

Answer 1