Ensure legacy networks does not exist

MediumLevel 1Automatedalibaba

Description

In order to prevent use of legacy networks, ECS instances should not have a legacy network configured. Legacy networks have a single network IPv4 prefix range and a single gateway IP address for the whole network. With legacy networks, you cannot create subnetworks or switch from legacy to auto or custom subnet networks. Counts ECS instances with InstanceNetworkType classic in every region; any instance on the legacy classic network fails. Read-only aliyun CLI calls; credentials and default region come from the CLI's normal profile (aliyun configure, ~/.aliyun/config.json or ALIBABA_CLOUD_* environment variables). JSON output is parsed with sed/awk. A missing CLI or credential fails the check.

How it is checked

Audit method: Shell command

shell

regs=$(aliyun ecs DescribeRegions 2>/dev/null) || exit 1
regions=$(printf '%s\n' "$regs" | sed -n 's/.*"RegionId"[[:space:]]*:[[:space:]]*"\([^"]*\)".*/\1/p' | sort -u)
[ -n "$regions" ] || exit 1
bad=0
for r in $regions; do
  out=$(aliyun ecs DescribeInstances --RegionId "$r" --InstanceNetworkType classic --PageSize 10 2>/dev/null) || exit 1
  n=$(printf '%s\n' "$out" | sed -n 's/.*"TotalCount"[[:space:]]*:[[:space:]]*\([0-9]\{1,\}\).*/\1/p' | head -n 1)
  [ "${n:-0}" -eq 0 ] || { echo "classic-network instances in $r: $n"; bad=1; }
done
[ "$bad" -eq 0 ] && echo compliant

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Migrate classic-network ECS instances to a VPC (ECS console > Instances > Migrate to VPC) and stop creating classic-network resources.

Properties

Operating systems: Any
Tags: alibabanetwork
Reference: CIS Alibaba Cloud Foundation Benchmark v2.0.1 - 3.1 Ensure legacy networks does not exist

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target alibaba