sql network interfaces error 26 error locating server instance specified microsoft sq

[UkDraxion]

Hi all, this is my first post so please be gentle.

I have a problem connecting to an instance on one of our sql servers.

The sql server currently has a number of other instances on it which seem to be working fine, but this one instance is proving a little awkwards.

I was able at one point to access the instance from sql management studio on my laptop, but then it was left for a while with no use and this morning I tried again and could not connect from anything outside the server.

I have checked the services are running ok.

I cannot ping the instance directly, but our server team guys can, I can still map a drive to the instance but that about all.

Getting the error message 'sql network interfaces error 26 error locating server instance specified microsoft sql server' when I try to connect from the management console.

is there any reason why it should stop working afte a period of time, and what could be causing this issue?

Cheers

[UkDraxion]

Hi all, I found the issue.

We had not opened up the UDP port 1434, once that was opened it worked fine.

Cheers