Radius server to Authenticate

[shansuresh]

Hi

I want to setup the radius server, so whenever anyone try to login into a cisco switch (telneting), I want the radius server to authenicate them. Is it possible?

[a.awan · Accepted solution]

Yes this is possible provided you configure your switches to authenticate against the Radius server. To achieve this you have to use a feature called AAA. This feature can work with protocols like Radius, TACACS+, to name a few. The following link will give you an idea as to how to configure it on IOS based switches specifically the 3550:

http://www.cisco.com/en/US/partner/products/hw/switches/ps646/products_configuration_guide_chapter09186a00801a6b15.html

Make sure that you apply the authentication list to vty lines to ensure that telnet access is authenticated against the radius server. Fot CatOS based switches the following link will prove helpful:

http://www.cisco.com/en/US/partner/tech/tk583/tk642/technologies_tech_note09186a0080094ea4.shtml

[shansuresh]

Thanks, That's really helped me.

Do you know where I can find the documentation on how to setup on the Radius server? As the above doucmentation only tells what I needed to configure on the Cisco switch but it fails to tell what what I need to configure on the RADIUS server?

[a.awan]

The way you configure the Radius server depends on the kind of Radius server you are using. However, to get the basic authentication process up and running all you need to configure on the Radius server is the client (your router or switch) and a way to authenticate the user logging into the client. Pretty much all radius servers support authentication against an internal user database which means that you configure the username and password on the radius server itself. They also let you integrate with an LDAP database or maybe with MS Windows Active Directory natively.To put you in the right direction i can suggest a few Radius servers you can look at:

1. Cisco System ACS. (supports both Radius and TACACS)

2. Funk Software Steel Belted Radius.

3. Microsoft IAS.

4. Free Radius (yes it is free as it is open source)