# MemoryDB and IPV6
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You can create new dual stack and ipv6-only clusters with both Valkey and Redis OSS engines, by providing subnet groups with dual stack and ipv6-only subnets. You cannot change the network type for an existing cluster.

With this functionality you can:
+ Create ipv4-only and dual stack clusters on dual stack subnets.
+ Create ipv6-only clusters on ipv6-only subnets.
+ Create new subnet groups to support ipv4-only, dual stack, and ipv6-only subnets.
+ Modify existing subnet groups to include additional subnets from the underlying VPC.
+ Modify existing subnets in subnet groups
  + Add IPv6 only subnets to subnet groups configured for IPv6
  + Add IPv4 or dual stack subnets to subnet groups configured for IPv4 and dual stack support
+ Discover all the nodes in the cluster with ipv4 OR ipv6 addresses, through engine discovery commands for dual stack and ipv6 clusters. These discovery commands include `redis_info`, `redis_cluster`, and similar.
+ Discover the ipv4 and ipv6 addresses of all the nodes in the cluster, through DNS discovery commands for dual stack and ipv6 clusters.