“No available servers for service 'domain1.example.com’ “ when multiple AD domains are configured.

Issue

• When multiple Active Directory domains are configured, SSSD attempts to connect to each of them. If one or more domains are unreachable, SSSD continues trying to resolve them we get "No available servers for service 'sd_domain1.example.com'" repeated error log in sssd_<domain>.log, which may lead to delayed authentication or failed logins for users.

  (2025-10-08 11:33:39): [be[corp.local]] [fo_resolve_service_send] (0x0020): [RID#6] No available servers for service 'sd_domain1.example.com'
  *  (2025-10-08 11:35:06): [be[corp.local]] [be_resolve_server_process] (0x0200): [RID#47] Found address for server server1.domain1.example.com: [192.168.121.32] TTL 2681
  *  (2025-10-08 11:35:06): [be[corp.local]] [ad_resolve_callback] (0x0100): [RID#47] Constructed uri 'ldap://server1.domain1.example.com'
  *  (2025-10-08 11:35:06): [be[corp.local]] [sssd_async_socket_init_send] (0x4000): [RID#47] Using file descriptor [28] for the connection.
  *  (2025-10-08 11:35:06): [be[corp.local]] [sssd_async_socket_init_send] (0x0400): [RID#47] Setting 6 seconds timeout [ldap_network_timeout] for connecting
  *  (2025-10-08 11:35:12): [be[corp.local]] [sssd_async_connect_timeout] (0x0100): [RID#47] The connection timed out [ldap_network_timeout]
  *  (2025-10-08 11:35:12): [be[corp.local]] [sssd_async_socket_init_done] (0x0040): [RID#47] sdap_async_sys_connect request failed: [110]: Connection timed out [ldap_network_timeout].