Catalog views are use to store information related to linked server logins, security and other features which are enabled for linked server.
Sys.linked_logins – We can fire select query on this Catalog view which stores Linked-server-login mapping information from local server to the corresponding linked server for execute distributed queries by using RPC.
select * FROM sys.linked_logins
Sys.remote_login – This Catalog view is used to map incoming local logins from a corresponding server to an actual local login.
select * FROM sys.remote_logins
Sys.servers – This Catalog view is used to store information related to linked or remote server registered. Also store data related to servers which are involve in the linked server like linked server name, server id, type servers, provider information and other feature related to linked server.
select * FROM sys.servers
By using these tables we can find out the servers which are involve linked server and corresponding features