Hello @SonalBK843 ,
Thanks for reaching out.
This issue seems to be more on DNS resolution (io.netty.resolver.dns.DnsNameResolverTimeoutException project) related than Azure Key vault starter.
The Azure SDKs support users to bring their own http client implementation while constructing the sdk client.
In addition that could you try to customize the reactor http client like this
https://projectreactor.io/docs/netty/release/reference/index.html#_host_name_resolution_2
Hope this helps.
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