Trinity Shibboleth Identity Provider (SAML 2.0 metadata)
Trinity's own Shibboleth IdP, self-hosted on its own registrable domain: idp.tcd.ie resolves through idpha.tcd.ie to 134.226.14.232, inside Trinity's 134.226.0.0/16 allocation. The metadata endpoint serves an unauthenticated SAML 2.0 EntityDescriptor (entityID https://idp.tcd.ie/idp/shibboleth) carrying an IDPSSODescriptor and a shibmd:Scope of tcd.ie. The entity is registered in HEAnet's Edugate federation and exported to eduGAIN, confirmed on the REFEDS Metadata Explorer. This is the strongest institution-operated, machine-readable contract Trinity publishes.