A request to allocate an ephemeral port number from the global UDP port space has failed due to all such ports being in use

Such a long title of error message, I got this error on the Win Server 2012, The server is running for more than 2 years and suddenly all my apps is hang.

The first things we want to check is what is the UDP Port is currently using there is 2 ways to check it.
1. Is using TCPView
2. Is using Command Prompt (netstat) it.

Open the Command Prompt “netstat -anob -p UDP > 20150414_1521.txt” It will save in this file.

We will see there is alot of list of “Dnscache” which is using PPID 3312

UDP    [::]:49656             *:*                                    3312

Moving forward we want to know what is the PPID 3312.
tasklist /svc /fi “pid eq 3312”

svchost.exe 3312 CryptSvc, Dnscache, LanmanWorkstation,
NlaSvc, WinRM

Based on this article it said to turn off the LLMNR Listener, on the last comment


From what we capture the network traffic we saw that .48 is calling LLMNR destination which is also state in this article:


To fix this issue I use the last article “Disabling LLMNR Causing Slow Network” and it work.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s