You plan to implement an Azure virtual network that will contain 10 virtual subnets. The subnets will use IPv6 addresses. Each subnet will host up to 200 load-balanced virtual machines.
You need to recommend which subnet mask size to use for the virtual subnets.
What should you recommend?
For IPv6 networks, the standard and recommended subnet size is /64. This provides a vast number of addresses, ensuring compatibility with various IPv6 functions and future scalability. A /64 subnet mask allows for auto-configuration of IP addresses, which is a fundamental feature of IPv6. Each subnet can easily accommodate the requirement of hosting up to 200 virtual machines.
"The subnets for IPv6 must be exactly /64 in size. This ensures future compatibility should you decide to enable routing of the subnet to an on-premises network since some routers can only accept /64 IPv6 routes." https://learn.microsoft.com/en-us/azure/virtual-network/ip-services/ipv6-overview#capabilities
IPv6 does NOT have /24 --> D is correct --> /64
U Mean A
/64 The subnets for IPv6 must be exactly /64 in size. This ensures future compatibility should you decide to enable routing of the subnet to an on-premises network since some routers can only accept /64 IPv6 routes. https://learn.microsoft.com/en-us/azure/virtual-network/ip-services/ipv6-overview#capabilities
IPv6-only Virtual Machines or Virtual Machines Scale Sets aren't supported, each NIC must include at least one IPv4 IP configuration. https://learn.microsoft.com/en-us/azure/virtual-network/ip-services/ipv6-overview So in that case its dual-stack, the ipv4 subnet mask for 200 VMs is /24. And Ipv6 subnet mask is /64. But its not clear mask which is asked in the question... assuming it is referring to ipv6 as mentioned initially, answer will be /64
should be /64
What is your explaining Bigfatdavye?
https://learn.microsoft.com/en-us/azure/virtual-network/ip-services/ipv6-overview#capabilities "Important The subnets for IPv6 must be exactly /64 in size. This ensures future compatibility should you decide to enable routing of the subnet to an on-premises network since some routers can only accept /64 IPv6 routes."
Could you explain ?
https://learn.microsoft.com/en-us/azure/virtual-network/ip-services/ipv6-overview#capabilities "Important The subnets for IPv6 must be exactly /64 in size. This ensures future compatibility should you decide to enable routing of the subnet to an on-premises network since some routers can only accept /64 IPv6 routes."
Definitely answer is A and most people not accepting A as answer is because their mindset is still WIRED to IPv4 IPV6 /64 will take billions of hosts not such 200 vms...you have to remember /64 is IPv6 as IPv4 is max /32 hence both are totally different but same concept, read below for more info Thus routing prefix is /64 and host portion is 64 bits. We can further subnet the network beyond 16 bits of Subnet ID, by borrowing host bits; but it is recommended that 64 bits should always be used for hosts addresses because auto-configuration requires 64 bits. IPv6 subnetting works on the same concept as Variable Length Subnet Masking in IPv4. /48 prefix can be allocated to an organization providing it the benefit of having up to /64 subnet prefixes, which is 65535 sub-networks, each having 264 hosts. A /64 prefix can be assigned to a point-to-point connection where there are only two hosts (or IPv6 enabled devices) on a link.
more info here https://docs.netgate.com/pfsense/en/latest/network/ipv6/subnets.html
This is wrong, a /120 can host 2^8 (256) ips
my bad -->not accepted below /64 so response 1 /64
my bad -->not accepted below /64 so response 1 /64
A /64 subnet mask provides an enormous address space of 2^64 addresses, which is far more than enough to accommodate the required number of virtual machines in each subnet (up to 200). Using a /64 subnet mask aligns with standard IPv6 practices and ensures compatibility with various IPv6 features and functionalities.
Chatgpt: /48 subnet mask in IPv6 provides 65,536 subnets, each with a vast address space of 18,446,744,073,709,551,616 addresses. This is more than enough to accommodate your requirement of hosting up to 200 load-balanced virtual machines in each of the 10 virtual subnets, and it allows for future scalability and flexibility in your network design.
and this is why I don't use chatGPT ;)
/ 24,Because of the number of host 254. from the question "Each subnet will host up to 200 load-balanced virtual machines."
Totally wrong your mindset is WIRED to IPv4, this is about IPv6, read my explanation
Definately A
Given the requirements, the best recommendation for the subnet mask size would be: B. /120 Here's the reasoning: IPv6 addressing: IPv6 has a much larger address space than IPv4, allowing for more granular subnetting. Subnet size: Each subnet needs to host up to 200 load-balanced virtual machines. /120 subnet mask: In IPv6, a /120 subnet provides 2^8 = 256 addresses. This is more than enough to accommodate 200 virtual machines per subnet while leaving some room for network infrastructure addresses (e.g., gateway). A /120 subnet mask offers the necessary address space while conserving address allocations for other potential subnets or uses within your Azure virtual network.
Chat GPT's "reasoning" is garbage. IPv6 subnets can have ONLY one mask: /64. No exceptions