Win32::Resolv.get_resolv_info returns unavailable DNS servers
Win32::Resolv.get_resolv_info returns a list of IP address that include DNS server for network devices that are not connected, causing long timeouts when using
Resolv::DNS (or Rubygems which uses
Win32::Resolv scans the registry for DNS server addresses. Unfortunatly, if some of your network devices are not currently connected, the old DNS information is still stored in registry. So
get_resolv_info still returns it. This can cause very long timeouts when using
Resolv::DNS (e.g. rubygems). For example, a simple 'gem install' on my machine would take over a minute, because of several timeouts waiting for DNS.
irb(main):024:0> Win32::Resolv.get_resolv_info => [["mynet", "mycompany.local", "local"], ["192.168.1.1", "172.27.0.1", "220.127.116.11", "18.104.22.168", "192.168.101.10", "192.168.101.11"]]
- 192.168.1.1 is the DNS server from my home Wifi (not currently connected)
- 172.27.0.1 is the DNS server from a router I had connected via an USB Ethernet Device a week ago
- 22.214.171.124 is from the same as above (but incidentally works, since it is available)
- 192.168.101.10+11 are the actual current DNS server
I think a solution could be to rely on
GetAdapterAddresses() in the Win32 API instead to get the IP address of DNS server.
As a workaround for users affected by this is to remove unconnected Interfaces from
HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces in the registry.
Updated by nobu (Nobuyoshi Nakada) over 5 years ago
- Status changed from Open to Closed
Applied in changeset r55781.
- ext/win32/resolv/resolv.c (get_dns_server_list): [Win32] get DNS servers only for connected network devices by GetNetworkParams API. [Bug #12604]
Updated by nagachika (Tomoyuki Chikanaga) almost 5 years ago
- Backport changed from 2.1: WONTFIX, 2.2: REQUIRED, 2.3: DONE to 2.1: WONTFIX, 2.2: REQUIRED, 2.3: REQUIRED
I reverted r57571 at r57626. r57571 broke RubyCI on vc12-x64.
I cannot have time to see in details to fix it just now, I temporarily reverted it.