将Google Cloud单区域传统网络迁移至自定义VPC遇IP错误求助

我尝试将Google Cloud单区域传统网络迁移至VPC网络，使用单区域转换工具和GKE网络转换脚本后，均碰到同一错误：

ERROR: (gcloud.beta.compute.networks.update) The first 2 IPs in this network's range 10.240.0.0/16 must be in used.

错误提及的前两个IP为网络IP10.240.0.0和默认网关10.240.0.1，这两个是传统网络默认分配的，无法手动修改。官方迁移指南仅要求确保网络最后两个IP10.240.0.254和10.240.0.255处于空闲状态，我环境中这两个IP确实未被占用，且指南的故障排查章节未提及该错误。有没有人遇到过此问题并找到解决办法？

EDIT-1：已使用的IP及关联资源 #

10.240.0.1      default gateway
10.240.0.3      compute#instance
10.240.0.4      compute#instance
10.240.0.7      compute#instance
10.240.0.18     compute#instance
10.240.0.22     compute#instance
10.240.0.23     compute#instance
10.240.0.28     compute#instance
10.240.0.31     compute#instance
10.240.0.34     compute#instance
10.240.0.37     compute#instance
10.240.0.39     compute#instance
10.240.0.43     compute#instance
10.240.0.44     compute#instance
10.240.0.56     compute#instance
10.240.0.58     compute#instance
10.240.0.60     compute#instance
10.240.0.68     compute#instance
10.240.0.75     compute#instance
10.240.0.81     compute#instance
10.240.0.84     compute#instance
10.240.0.101    compute#instance
10.240.0.105    compute#instance
10.240.0.106    compute#instance
10.240.0.109    compute#instance
10.240.0.111    compute#instance
10.240.0.117    compute#instance
10.240.0.123    compute#instance
10.240.0.124    compute#instance
10.240.0.133    compute#instance
10.240.0.137    compute#instance
10.240.0.175    compute#instance
10.240.92.185   compute#instance
10.240.117.221  compute#instance

EDIT-2：使用的命令及输出 #

GKE网络转换脚本命令 #

gkeconvert                                \
 --project=<project-name>                 \
 --network=<legacy-network-name>          \
 --control-plane-version=1.23.14-gke.1800 \
 --node-version="-"                       \
 --validate-only=false

输出：

INFO[0000] Fetching network <legacy-network-name> for project "<project-name>"
INFO[0001] Initialize objects for conversion.
INFO[0002] Initialize NodePool objects for Cluster projects/<project-name>/locations/<gcloud-zone>/clusters/<gke-cluster-name>
INFO[0005] Validate resources for conversion.
INFO[0005] Upgrade for Cluster projects/<project-name>/locations/<gcloud-zone>/clusters/<gke-cluster-name> is valid
INFO[0005] Validate NodePool upgrade(s) for Cluster projects/<project-name>/locations/<gcloud-zone>/clusters/<gke-cluster-name>
INFO[0005] Upgrade for NodePool projects/<project-name>/locations/<gcloud-zone>/clusters/<gke-cluster-name>/nodePools/<pool-1-name> is valid
INFO[0005] Upgrade for NodePool projects/<project-name>/locations/<gcloud-zone>/clusters/<gke-cluster-name>/nodePools/<pool-2-name> is valid
INFO[0005] Upgrade for NodePool projects/<project-name>/locations/<gcloud-zone>/clusters/<gke-cluster-name>/nodePools/<pool-3-name> is valid
INFO[0005] Upgrade for NodePool projects/<project-name>/locations/<gcloud-zone>/clusters/<gke-cluster-name>/nodePools/<pool-4-name> is valid
INFO[0005] Upgrade for NodePool projects/<project-name>/locations/<gcloud-zone>/clusters/<gke-cluster-name>/nodePools/<pool-5-name> is valid
INFO[0005] Initiate resource conversion.
INFO[0005] Switching legacy network projects/<project-name>/global/networks/<legacy-network-name> to custom mode VPC network
Error: error waiting on Operation projects/<project-name>/global/operations/operation-xxxxxxxx-xxxxxxxx-xxxxxxxx-xxxxxx: The first 2 IPs in this network's range 10.240.0.0/16 must be in used.

单区域转换工具命令 #

gcloud beta compute networks update <legacy-network-name>  --switch-to-custom-subnet-mode

输出：

Network [<legacy-network-name>] will be switched to custom mode. This operation cannot be undone.

Do you want to continue (Y/n)?  Y

X Migrating Network from Legacy to Custom Mode
  . Validating Network
  . Creating Subnetwork
  . Updating Instances
  . Updating Instance Groups
  . Updating Forwarding Rules
  . Converting Network to Subnet Mode
Failed.
ERROR: (gcloud.beta.compute.networks.update) The first 2 IPs in this network's range 10.240.0.0/16 must be in used.

解决方法 #

1. 手动预创建匹配子网
   转换前先手动创建和传统网络CIDR一致的子网，明确绑定网关IP为10.240.0.1，让系统识别到该IP已被使用：

   gcloud compute networks subnets create <subnet-name> \
     --network=<legacy-network-name> \
     --range=10.240.0.0/16 \
     --region=<your-region> \
     --gateway-address=10.240.0.1
   

2. 重新执行转换命令
   子网创建完成后，再运行之前的转换工具或脚本，此时系统会跳过自动创建子网的步骤，直接使用已创建的子网，避免校验错误。

3. 验证转换结果
   转换完成后，检查子网配置及实例的网络关联状态，确认所有资源正常接入VPC网络。

内容的提问来源于stack exchange，提问作者vahiiid