Introduction - Why Cisco Password Types Matter
Cisco networking devices have evolved for decades, and so have their password encryption methods. Each generation of Cisco IOS and IOS-XE introduced new password types to address emerging security threats and compliance requirements.
In short:
Cisco passwords range from cleartext (Type 0) to modern cryptographic standards (Type 9).
Understanding these differences is essential to protect your network from unauthorized access.
| Security Level | Weak → Strong |
| Type 0 / 7 | Obsolete |
| Type 5 | Transitional |
| Type 8 / 9 | Secure (Best Practice) |
Cisco Password Evolution Overview
| Generation | Type | Algorithm | Introduced | Status | Security Level |
| Legacy | 0 | Plaintext | Pre-2000 | Obsolete | Very Weak |
| Legacy | 7 | Vigenère Cipher | Pre-2000 | Obsolete | Very Weak |
| Transitional | 4 | Flawed SHA-256 | 2010 | Deprecated | Weak |
| Classic | 5 | MD5 (salted) | 2000 | Legacy | Medium |
| Modern | 8 | PBKDF2-HMAC-SHA256 | 2014 | Secure | Strong |
| Modern | 9 | scrypt (memory-hard) | 2016 | Best Practice | Very Strong |
In essence: Types 8 and 9 are today’s standards for strong Cisco password encryption. Older types should be retired wherever possible.
Cisco Password Type Comparison Table
| Type | Algorithm | Encryption Strength | Crackability | Hashcat Mode | Recommendation |
| 0 | Plaintext | None | Instant | N/A | ❌ Never use |
| 7 | Vigenère Cipher | Very Weak | Instant | N/A | ❌ Never use |
| 4 | Flawed SHA-256 | Low | Seconds | 5700 | ❌ Deprecated |
| 5 | MD5 (Salted, 1000x) | Medium | Minutes | 500 | ⚠️ Legacy |
| 8 | PBKDF2-SHA256 (20,000x) | High | Difficult | 9200 | ✅ Secure |
| 9 | scrypt (memory-hard) | Very High | Very Hard | 9300 | ✅ Best Practice |
Type 9 uses memory-intensive encryption to resist GPU and ASIC cracking - currently Cisco’s strongest algorithm.
Understanding Cisco Password Types
Legacy Types - Type 0 and Type 7
Type 0 (Plaintext)
- Appears unencrypted (e.g., password cisco123).
- Offers zero protection; visible in configuration files.
- Never use in production.
Type 7 (Vigenère Cipher)
- Uses a reversible cipher, easily decoded.
- Example: password 7 0832585D0A16
- Replace with Type 8 or Type 9 immediately.
Transitional Types — Type 4 and Type 5
Type 4 (Broken SHA-256)
- Designed for PBKDF2 but implemented incorrectly (no salt, single iteration).
- Removed from Cisco IOS after 15.3(3)M3.
- Deprecated and insecure.
Type 5 (MD5 Salted)
- Uses salted MD5 hash (1,000 iterations).
- Example CLI: enable secret 5 $1$GgghHhJ7$3LxDSE8US1E
- Still crackable with modern GPU tools.
- Only use when Type 8/9 not supported.
Modern Secure Types — Type 8 and Type 9
Type 8 (PBKDF2-HMAC-SHA256)
80-bit salt, 20,000 iterations.
Strong, standards-compliant implementation.
Example commands:
- Switch(config)# enable algorithm-type sha256 secret MyStrongPassword
- Switch(config)# username admin algorithm-type sha256 secret Cisco@2025
Recommended for most deployments.
Type 9 (scrypt)
Memory-hard algorithm — resistant to parallel cracking (GPUs, ASICs)
Example commands:
- Switch(config)# enable algorithm-type scrypt secret SecurePass99
- Switch(config)# username admin algorithm-type scrypt secret Cisco@Secure
Best Practice — the highest level of Cisco password security.
Quick Summary: Use Type 9 when available → fallback to Type 8 → eliminate Type 0, 4, and 7.
Migration & Upgrade Strategy
Migration Checklist
| Step | Action | Command Example |
| 1 | Check IOS version | show version |
| 2 | Verify supported algorithms | ? enable algorithm-type |
| 3 | Create new secure passwords | enable algorithm-type scrypt secret |
| 4 | Replace all Type 0/7/5 passwords | Update local accounts |
| 5 | Delete obsolete entries | no username |
| 6 | Test access methods | SSH, console, web |
| 7 | Backup configuration | Encrypt backup file (AES-256 ZIP) |
Firmware Note: Type 8 and 9 require IOS 15.3(3)M3 or later. Upgrade before migration if not supported.
Authorized Security Testing
Only perform password hash testing during approved internal audits.
| Type | Hashcat Example | John Format |
| 5 | hashcat -m 500 file.hash wordlist.txt | --format=md5crypt |
| 8 | hashcat -m 9200 file.hash wordlist.txt | --format=pbkdf2-hmac-sha256 |
| 9 | hashcat -m 9300 file.hash wordlist.txt | --format=scrypt |
Legal Disclaimer: Never use password-cracking tools without written authorization. Unauthorized use is illegal and unethical.
Cisco Password Security Best Practices
- Always use Type 8 or Type 9 for all local and enable secrets.
- Disable legacy password lines using Type 0/7.
- Enforce complex passwords (>12 characters, mixed case & symbols).
- Regularly verify password types with:bash复制编辑show running-config | include secret
- Integrate TACACS+ or RADIUS for centralized authentication.
- Encrypt configuration backups (AES-256 or encrypted ZIP).
- Conduct periodic audits for weak hashes (grep for “password 7”).
Compliance Tip: Type 9 passwords meet NIST SP 800-63 and modern cryptographic policy requirements.
FAQ - Common Questions
Q1: How do I identify which password type is used?
A: Check the number after secret or password. Example: enable secret 9 $9$… = Type 9.
Q2: Are Type 5 and Type 8 compatible?
A: Yes. They can coexist in configs, but Type 8/9 require IOS 15.3(3)M3+.
Q3: Why are Type 7 passwords still appearing?
A: They remain from older configurations (e.g., console or SNMP lines). Replace manually.
Q4: What if my IOS doesn’t support Type 9?
A: Use Type 8 (PBKDF2) until upgrade possible.
Q5: Does NX-OS or ASA use the same password types?
A: Not exactly. NX-OS supports Type 5/8; ASA uses a similar SHA-based scheme. Always confirm per platform.
Conclusion - Adopt Modern Encryption Now
Cisco’s password algorithms evolved from simple obfuscation to industry-grade cryptography. By upgrading to Type 8 or 9, network administrators ensure:
- Strong protection against brute-force attacks
- Compliance with security frameworks
- Long-term configuration integrity
Network-Switch Expert Insight: “Upgrading to Type 9 is a small change with a huge security payoff — it’s the easiest way to harden your Cisco infrastructure today.”
Visit Network-Switch.com for Cisco configuration templates, IOS upgrade guidance, and professional security consulting.
Did this article help you or not? Tell us on Facebook and LinkedIn . We’d love to hear from you!
https://network-switch.com/pages/about-us