| 389 | LDAP ldap | TCP UDP | 6/10 high | optional |
| 636 | LDAPS ldaps | TCP UDP | 5/10 moderate | yes |
| 88 | Kerberos kerberos | TCP UDP | 6/10 high | yes |
| 3268 | Global Catalog (LDAP) msft-gc | TCP UDP | 6/10 high | optional |
| 1812 | RADIUS radius | UDP TCP | 5/10 moderate | no |
| 31 | MSG Authentication msg-auth | TCP UDP | - | - |
| 49 | Login Host Protocol (TACACS) tacacs | TCP UDP | - | - |
| 56 | XNS Authentication xns-auth | TCP UDP | - | - |
| 113 | Authentication Service auth, ident | TCP UDP | - | - |
| 129 | Password Generator Protocol pwdgen | TCP UDP | - | - |
| 191 | Prospero Directory Service prospero | TCP UDP | - | - |
| 197 | Directory Location Service dls | TCP UDP | - | - |
| 198 | Directory Location Service Monitor dls-mon | TCP UDP | - | - |
| 221 | Berkeley rlogind with SPX auth fln-spx | TCP UDP | - | - |
| 300 | TLS Secure Login Host Protocol (TACACSS) tacacss | TCP | - | - |
| 323 | Resource PKI to Router Protocol rpki-rtr | TCP | - | - |
| 324 | Resource PKI to Router Protocol over TLS rpki-rtr-tls | TCP | - | yes |
| 464 | kpasswd kpasswd | TCP UDP | - | - |
| 472 | ljk-login ljk-login | TCP UDP | - | - |
| 491 | go-login go-login | TCP UDP | - | - |
| 586 | Password Change password-chg | TCP UDP | - | - |
| 749 | kerberos administration kerberos-adm | TCP UDP | - | - |
| 750 | kerberos version iv kerberos-iv, loadav, rfile | UDP TCP | - | - |
| 1151 | Unizensus Login Server unizensus | TCP UDP | - | - |
| 1333 | Password Policy passwrd-policy | TCP UDP | - | - |
| 1615 | NetBill Authorization Server netbill-auth | TCP UDP | - | - |
| 1760 | www-ldap-gw www-ldap-gw | TCP UDP | - | - |
| 1813 | RADIUS Accounting radius-acct | TCP UDP | - | - |
| 1918 | IBM Tivole Directory Service - NDS can-nds | TCP UDP | - | - |
| 1919 | IBM Tivoli Directory Service - DCH can-dch | TCP UDP | - | - |
| 1920 | IBM Tivoli Directory Service - FERRET can-ferret | TCP UDP | - | - |
| 2083 | Secure Radius Service radsec | TCP UDP | - | - |
| 2139 | IAS-AUTH ias-auth | TCP UDP | - | - |
| 2147 | Live Vault Authentication lv-auth | TCP UDP | - | - |
| 2334 | ACE Client Auth ace-client | TCP UDP | - | - |
| 2366 | qip-login qip-login | TCP UDP | - | - |
| 2392 | Tactical Auth tacticalauth | TCP UDP | - | - |
| 2478 | SecurSight Authentication Server (SSL) ssm-cssps | TCP UDP | - | - |
| 2710 | SSO Service sso-service | TCP UDP | - | - |
| 2711 | SSO Control sso-control | TCP UDP | - | - |
| 2821 | VERITAS Authentication Service vrts-at-port | TCP UDP | - | - |
| 3024 | NDS_SSO nds_sso, nds-sso | TCP UDP | - | - |
| 3113 | CS-Authenticate Svr Port cs-auth-svr | TCP UDP | - | - |
| 3207 | Veritas Authentication Port vx-auth-port | TCP UDP | - | - |
| 3269 | Microsoft Global Catalog with LDAP/SSL msft-gc-ssl | TCP UDP | - | yes |
| 3407 | LDAP admin server port ldap-admin | TCP UDP | - | - |
| 3411 | BioLink Authenteon server biolink-auth | TCP UDP | - | - |
| 3437 | Autocue Directory Service autocueds | TCP UDP | - | - |
| 3538 | IBM Directory Server ibm-diradm | TCP UDP | - | - |
| 3539 | IBM Directory Server SSL ibm-diradm-ssl | TCP UDP | - | - |
| 3660 | IBM Tivoli Directory Service using SSL can-nds-ssl | TCP UDP | - | - |
| 3661 | IBM Tivoli Directory Service using SSL can-ferret-ssl | TCP UDP | - | - |
| 3710 | PortGate Authentication portgate-auth | TCP UDP | - | - |
| 3735 | Password Distribution pwdis | TCP UDP | - | - |
| 3799 | RADIUS Dynamic Authorization radius-dynauth | TCP UDP | - | - |
| 3833 | AIPN LS Authentication aipn-auth | TCP UDP | - | - |
| 3868 | DIAMETER diameter | TCP SCTP | - | - |
| 4032 | VERITAS Authorization Service vrts-auth-port | TCP UDP | - | - |
| 4043 | Neighbour Identity Resolution nirp | TCP UDP | - | - |
| 4129 | NuFW authentication protocol nuauth | TCP UDP | - | - |
| 4604 | Identity Registration Protocol irp | TCP | - | - |
| 4952 | SAG Directory Server sagxtsds | TCP UDP | - | - |
| 5059 | SIP Directory Services sds | TCP UDP | - | - |
| 5318 | PKIX Certificate Management using CMS (CMC) pkix-cmc | TCP | - | - |
| 5635 | SFM Authentication Subsystem sfmsso | TCP | - | - |
| 5725 | Microsoft Identity Lifecycle Manager ms-ilm | TCP | - | - |
| 5757 | OpenMail X.500 Directory Server x500ms | TCP UDP | - | - |
| 5868 | Diameter over TLS/TCP diameters | TCP SCTP | - | yes |
| 6268 | Grid Authentication grid | TCP UDP | - | - |
| 6269 | Grid Authentication Alt grid-alt | TCP UDP | - | - |
| 6301 | BMC CONTROL-D LDAP SERVER bmc_ctd_ldap, bmc-ctd-ldap | TCP UDP | - | - |
| 6670 | Vocaltec Global Online Directory vocaltec-gold | TCP UDP | - | - |
| 7004 | AFS/Kerberos authentication service afs3-kaserver | TCP UDP | - | - |
| 7847 | A product key authentication protocol made by CSO csoauth | TCP | - | - |
| 9002 | DynamID authentication dynamid | TCP UDP | - | - |
| 9389 | Active Directory Web Services adws | TCP | - | - |
| 9612 | StreamComm User Directory streamcomm-ds | TCP UDP | - | - |
| 9629 | UniPort SSO Controller uniport | TCP UDP | - | - |
| 13832 | Certificate Management and Issuing a-trust-rpc | TCP | - | - |
| 21846 | NetSpeak Corp. Directory Services netspeak-is | TCP UDP | - | - |
| 23294 | 5AFE SDN Directory 5afe-dir, 5afe-disc | TCP UDP | - | - |
| 24321 | Isolv Local Directory ild | TCP UDP | - | - |
| 27999 | TW Authentication/Key Distribution and tw-auth-key | TCP UDP | - | - |