/etc/krb5.conf.
Setup
krb5.conf
Most Linux tools read/etc/krb5.conf to find the KDC. Without it, Kerberos auth will fail with KDC not found or Cannot contact any KDC.
/etc/hosts
Kerberos tickets bind to FQDNs. IP targets will fail even with a valid ticket.Getting a TGT
Tool Reference
SMB
Remote Execution
LDAP
RPC / Other Impacket Tools
Certipy
Common Errors
| Error | Cause | Fix |
|---|---|---|
KDC_ERR_SKEW / Clock skew too great | System clock > 5 min off from DC | faketime -f '+Xh' bash or sync NTP |
KDC can't be contacted | Missing or wrong krb5.conf | Check /etc/krb5.conf realms and KDC entry |
No credentials cache found | KRB5CCNAME not set | export KRB5CCNAME=user.ccache |
Ticket expired | ccache is stale | Re-run getTGT.py and refresh KRB5CCNAME |
Target IP instead of FQDN | Tool resolving to IP | Use FQDN in target, check /etc/hosts |
nxc: STATUS_NOT_SUPPORTED | nxc falling back to NTLM | Always pair -k with --use-kcache and FQDN |
KDC_ERR_PREAUTH_FAILED | Wrong password/hash for AS-REQ | Verify creds; try AES key if RC4 is disabled |
KRB_AP_ERR_BAD_INTEGRITY | Wrong service ticket or wrong key | Re-request ST with correct -spn |