Exam Professional Cloud Network Engineer topic 1 question 65 discussion

I think it's B. "This will be a VPC native cluster, and the *default* Pod IP range allocation will be used." From https://cloud.google.com/kubernetes-engine/docs/how-to/flexible-pod-cidr#overview "With the *default* maximum of 110 Pods per node, Kubernetes assigns a /24 CIDR block (256 addresses) to each of the nodes." That is, /24 for one node. We have 3 nodes, so we need /22.

TL;DR: correct answer /22 Max nodes will be three. Each node can have a max of 254 pods. 254 * 3 -> 762 pods Both a /25 and /23 wouldn't be enough --> those would respectively account for 128 and 512 pods /21 would be too large -> that would be enough for 2048 pods /22 is the right one, accounting for 1024 PODs

I think it should be /21, considering each node can have 256 pods and the address block always contains at least twice as many addresses as the maximum number of Pods per node as per documentation. 256(max pods per node)*3 nodes=768 pods 768(total max pods)*2=1536(twice the total pods) addresses And /21 range satisfies this.

Answer is C: /23 3 nodes with max of 110 pods = 330 pods. the real answer is /24 for a total of 510 IPs.. /25 gives you 254 IPs... Since /24 is not a option the next best is /23

It’s B

/22 allows 4 nodes, since each node needs /24 allocated for Pods (110 pods per node)

Answer is B see the table attached for 4 nodes and 330 pods( 440 is max size )

Option D (/25) is the correct answer because it allows for the minimum number of Pod IP addresses while still providing enough IP addresses for the maximum of three nodes in the cluster. A /25 subnet mask provides 128 IP addresses, which is enough for a single node cluster (with one IP address used for the node) and for a three node cluster (with one IP address used for each node). Option A (/21) provides more IP addresses than necessary and could result in IP address wastage. Option B (/22) and Option C (/23) also provide more IP addresses than necessary for a single node cluster and may lead to IP address wastage. So, the best option is to use a /25 subnet mask to allocate the minimum number of Pod IP addresses while still providing enough IP addresses for the maximum of three nodes in the cluster.

The corre tra answer is B. /24 is the default CIDR block assigned to each worker node, with maximum 110 PODs for node. For 3 node, we need 3 x /24 = /22

Answer is : B

Answer is : B

it's B https://cloud.google.com/kubernetes-engine/docs/concepts/alias-ips#defaults_limits

B https://cloud.google.com/kubernetes-engine/docs/concepts/alias-ips#defaults_limits

https://cloud.google.com/kubernetes-engine/docs/concepts/alias-ips#cluster_sizing_secondary_range_pods

Correction to my below reply - Each node will have max of 2^8 =256 , so for 3 nodes it will be 254*3 = 762. If you chose /23 then 2^(32-23) = 2^9 = 512 which is less than 762 so incorrect option .if you do the same thing for /22 you get 2048 which is more than 762 hence option B /22 is correct

Each node will have max of 2^8 =254 , so for 3 nodes it will be 254*3 = 762. If you chose /23 then 2^(32-23) = 2^9 = 512 which is less than 762 so incorrect option .if you do same thing for /212 you get 2048 which is more than 762 hence option B /21 is correct

B is the answer. When the "default" Pod IP range allocation is used, GKE assigns /24 CIDR block for pods on each node, which means the minimum secondary IP range of the subnet is /24, and that allows for max 1 node in your cluster. To expand to 3 Nodes, /22 range is required.