So I am having an issue with a Domain trust. My domain has three domain trusts, domain A, B and C. Domain A is a Forest trust and Domain B and C are External trusts. All three trusts have been verified. I create a share on a server on my domain. I go to grant users access, I select domain A and the users lookup pops right up, I search for my users and am able to add them. I then select domain B and the same happens, the user lookup opens and I can add a user. I then select domain C and prior to the user lookup opening up it asks me for credentials for domain C. Now if I enter in a user from domain C I can then select a user and add them to the share and the share functions as expected.
My question is what am I missing on the trust on domain C that causes user lookup to require credentials from domain C to add users.
I have confirmed that the Admin on domain C is seeing the same action when adding users from my domain to shares on his servers.
I found the problem to be quite simple. Once the trust was crested I needed to restart the server that I was applying the user permissions to. Once I rebooted the PC I was able to assign permissions to the shares to users in a trusted domain without being prompted for credentials.