Information
RadSec Server: RadSec (RADIUS over TLS) is a secure extension of RADIUS that encrypts RADIUS communication using TLS. It provides secure authentication, authorization (through RBAC) and accounting for AOS-CX switches over untrusted networks like the WANs.
Unlike traditional RADIUS, which uses UDP and leaves communication vulnerable, RadSec ensures transport-layer encryption with TLS, offering enhanced security. RadSec is more suitable for environments where RADIUS traffic traverses public or untrusted networks. Local authentication, while simple, lacks centralized management and scalability.
Solution
Prerequisite for TLS - The RadSec connection between the switch and RadSec server requires TLS with mutual authentication. The switch and RadSec servers exchange digital certificates as a part of TLS mutual authentication. Also, RadSec mandates validating server certificates SAN/CN while establishing connections.
To associate the Leaf Certificate for RadSec -
switch(config)# crypto pki application radsec-client certificate <certificate-name>
To Configure RadSec Server -
switch(config)# radius-server host {<FQDN> | <IPV4> | <IPV6>} tls [vrf <VRF-NAME>]
To Associate RadSec Server to the group -
switch(config)# aaa group server radius <group-name>
switch(config-sg) # server <FQDN | IPv4 | IPv6> tls vrf <vrf>
switch(config-sg) # exit
Impact:
Deploying RadSec improves data security by ensuring all authentication traffic is encrypted, reducing the risk of interception or tampering. It is especially beneficial in distributed networks with remote sites. However, it may require additional certificate configurations, increasing operational complexity.