### Old Way (Pre-9.7 ASA Versions and Older IOS Versions):
- **OSPF Authentication Configuration**: Both the ASA and IOS routers allowed for either **simple password authentication** or **MD5 authentication** directly on the interface or under the OSPF process.
- **No Key-Chain**: Key-chains were not used for OSPF authentication in either ASA or IOS router configurations.
- **Simple and MD5 Authentication**:
- **Simple Authentication**: A plain-text password was configured.
- **MD5 Authentication**: MD5 hash was used for enhanced security.
Example of old OSPF authentication on ASA:
router ospf 1
network 192.168.1.0 255.255.255.0 area 0
interface GigabitEthernet0/0
ip address 192.168.1.1 255.255.255.0
ip ospf authentication message-digest
ip ospf message-digest-key 1 md5 mypassword
Example of old OSPF authentication on IOS Router:
router ospf 1
network 192.168.1.0 0.0.0.255 area 0
interface GigabitEthernet0/0
ip address 192.168.1.1 255.255.255.0
ip ospf authentication message-digest
ip ospf message-digest-key 1 md5 mypassword
### New Way (Post-9.7 ASA Versions and Newer IOS Versions):
The "new way" for configuring OSPF authentication on both ASA and IOS routers is largely similar to the old way, with minor updates reflecting improved practices and syntax standardization across Cisco devices.
1. **Consistency**:
- Both ASA and IOS routers continue to configure OSPF authentication without using key-chains, ensuring consistency in configuration syntax across both platforms.
2. **Interface-Level Configuration**:
- Both platforms allow for more flexible, interface-level OSPF configuration, although the specific commands may have been refined to improve clarity and function.
3. **Enhanced Security Options**:
- While the basic OSPF authentication commands remain largely the same, newer platforms offer better integration with modern security practices, such as improved cryptographic support across other features, even though OSPF itself remains relatively unchanged.
Example of new OSPF authentication on ASA:
router ospf 1
network 192.168.1.0 255.255.255.0 area 0
interface GigabitEthernet0/0
ip address 192.168.1.1 255.255.255.0
ospf authentication message-digest
ospf message-digest-key 1 md5 newpassword
Example of new OSPF authentication on IOS Router:
router ospf 1
network 192.168.1.0 0.0.0.255 area 0
interface GigabitEthernet0/0
ip address 192.168.1.1 255.255.255.0
ospf authentication message-digest
ospf message-digest-key 1 md5 newpassword
### Summary:
- **Key-Chains**: Neither the old nor the new method of configuring OSPF authentication on ASA or IOS routers involves the use of key-chains. This remains unchanged.
- **Consistency Across Platforms**: The configuration of OSPF authentication is consistent across ASA and IOS routers, with both platforms continuing to use the same commands for simple password or MD5 authentication.
- **Minor Syntax Improvements**: The newer approach may include slight updates to syntax or additional commands that offer more flexibility or clarity, but the basic process remains familiar.
Overall, while there have been improvements in the surrounding features and platform capabilities, the configuration of OSPF authentication on ASA and IOS routers has remained stable, ensuring ease of use and consistency across different Cisco devices.
