Hi everyone, I’m working on a project where I need to resolve hostnames or Fully Qualified Domain Names (FQDNs) to a list of IP addresses. The use case involves resolving a hostname to about a dozen or two IP addresses, and I’m evaluating which function would be most suitable for this purpose between GetAddrinfoEx and DNSQueryEx . Here are my questions: What are the key differences between GetAddrinfoEx and DNSQueryEx in terms of performance, flexibility, intended use cases and ease of use for resolving multiple IPs from hostnames/FQDNs? Is there a specific situation where one function would be preferred over the other for resolving a hostname or FQDN to multiple IP addresses (i.e., in cases with high availability or multiple DNS records)? Which one would you recommend for resolving a hostname to multiple IP addresses efficiently in a scenario with as low as 1 -2 to dozen or more addresses? Any insights into the advantages or best practices for using either of these functions in this context would be greatly appreciated! Thanks in advance!

Choosing Between GetAddrinfoEx and DNSQueryEx for Efficiently Resolving Multiple IP Addresses from Hostnames

Harshal Goyal 20

Hi everyone,

I’m working on a project where I need to resolve hostnames or Fully Qualified Domain Names (FQDNs) to a list of IP addresses. The use case involves resolving a hostname to about a dozen or two IP addresses, and I’m evaluating which function would be most suitable for this purpose between GetAddrinfoEx and DNSQueryEx.

Here are my questions:

What are the key differences between GetAddrinfoEx and DNSQueryEx in terms of performance, flexibility, intended use cases and ease of use for resolving multiple IPs from hostnames/FQDNs?
Is there a specific situation where one function would be preferred over the other for resolving a hostname or FQDN to multiple IP addresses (i.e., in cases with high availability or multiple DNS records)?
Which one would you recommend for resolving a hostname to multiple IP addresses efficiently in a scenario with as low as 1 -2 to dozen or more addresses?

Any insights into the advantages or best practices for using either of these functions in this context would be greatly appreciated!

Thanks in advance!

Jeanine Zhang-MSFT 10,356 Reputation points Microsoft Vendor

2025-01-02T08:05:23.7866667+00:00

If you want to hostname resolution, I suggest you use GetAddrInfoEx.

I suggest you could refer to the links:

https://stackoverflow.com/a/51812514

https://learn.microsoft.com/en-us/windows-hardware/drivers/network/resolving-host-names-and-ip-addresses
Harshal Goyal 20 Reputation points

2025-01-03T04:14:37.4133333+00:00
Hi @Jeanine Zhang-MSFT ,

Thanks for your response! I appreciate the recommendation to use GetAddrInfoEx. However, I would love to get a bit more context and detailed insight into your reasoning.

Could you elaborate on the key differences between GetAddrInfoEx and DNSQueryEx in terms of:

Performance – How do these two functions compare in terms of speed and resource usage when resolving multiple IP addresses (in the range of 1-2 to a dozen or more)?

Flexibility – How do they differ in terms of supporting different DNS record types (A, AAAA, PTR, etc.) or dealing with DNS-based load balancing or multiple records?

Intended use cases – Are there scenarios where one would be clearly more suitable than the other (e.g., handling high availability or failover)?

Ease of use – Which function would be easier to implement for resolving multiple IP addresses in my specific use case, and are there any best practices for using them efficiently in this context?

I'd really appreciate your detailed thoughts on these points to help me make a more informed decision.

Thanks again!
Jeanine Zhang-MSFT 10,356 Reputation points Microsoft Vendor

2025-01-03T07:55:18.2433333+00:00

Your question involves the internal implementation logic of the API, which is out of our support scope. If you don't have any special requirements, it is recommended to use GetAddrInfoEx directly.

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Choosing Between GetAddrinfoEx and DNSQueryEx for Efficiently Resolving Multiple IP Addresses from Hostnames

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