RADIUS and Cisco 2611 router

Question

Greetings. First, let me start by saying I am an idiot, I know I am an idiot, and I apologize for wasting everyone's time. I have actually RTFM, many RTFMs, in fact, and I still have not found a resolution.
Second, I am trying to set up a RADIUS server in my test network. I have installed ClearBox RADIUS on a Windows 2000 system. I have the following configuration on my Cisco 2611 router:
Using 2297 out of 29688 bytes
! Last configuration change at 17:20:27 PDT Tue May 20 2008
! NVRAM config last updated at 17:20:29 PDT Tue May 20 2008
version 12.1
no service single-slot-reload-enable
service timestamps debug datetime msec localtime show-timezone
service timestamps log datetime msec localtime show-timezone
service password-encryption
hostname Tester
logging buffered 10000 debugging
aaa new-model
aaa group server radius RadiusServers
server 172.26.0.2 auth-port 1812 acct-port 1813
aaa authentication login default group RadiusServers local
aaa authentication login localauth local
aaa authentication ppp default if-needed group radius local
aaa authorization exec default group radius local
aaa authorization network default group radius local
aaa accounting delay-start
aaa accounting exec default start-stop group radius
aaa accounting network default start-stop group radius
aaa processes 6
enable secret xxx
username test password xxx
clock timezone PST -8
clock summer-time PDT recurring
ip subnet-zero
no ip domain-lookup
no ip bootp server
interface Loopback0
ip address 192.168.0.1 255.255.255.0
interface Ethernet0/0
description To Main Network
ip address X.X.X.X 255.255.255.128
no ip redirects
no ip unreachables
no ip proxy-arp
ip nat outside
full-duplex
no cdp enable
interface Ethernet0/1
description To Internal Network
ip address 172.26.0.1 255.255.255.0
no ip redirects
no ip unreachables
no ip proxy-arp
ip nat inside
load-interval 30
full-duplex
no cdp enable
ip nat pool test X.X.X.X X.X.X.X netmask 255.255.255.128
ip nat inside source list 3 pool test overload
ip nat inside destination list 3 pool test
ip classless
ip route 0.0.0.0 0.0.0.0 X.X.X.X
no ip http server
ip radius source-interface Ethernet0/1
access-list 3 permit 172.26.0.0 0.0.0.255
no cdp run
snmp-server community public RO 15
radius-server host 172.26.0.2 auth-port 1812 acct-port 1813 key secret
radius-server retransmit 3
radius-server key secret
line con 0
password xxx
logging synchronous
line aux 0
line vty 0 4
access-class 10 in
password 7 1234567890
logging synchronous
ntp clock-period 17208108
ntp server 192.43.244.18
end
My RADIUS server is up and responding to requests, but my router does not appear to be forwarding authentication requests to it. In fact, when I log into the router using HyperTerm, it times out, and I end up authenticating locally.
I really don't care whether my Cisco equipment authenticates against the RADIUS server, but I do need to get it set up to authenticate my users so I can track their time online. What have I missed in my router configuration? Why isn't it forwarding user authentication requests to the RADIUS server.
Thank you for any assistance you may be able to provide.

Answer 1

I have found that if I am in the middle of composing a response, and I open the thread in another browser window (to refer to it), when I go to submit my response, it doesn't get posted. Perhaps you are running into the same thing.
The command I shared:
aaa authentication enable default group radius local
... was erroneous. The keyword should have been "enable", as you have discovered.
Therefore use:
aaa authentication enable default group radius enable
When I view a Wireshark trace I see the following:
AVP: l=18 t=User-Password(2): Decrypted: "user-PWD\000\000\000\000\000\000\000\000"
Like you, I see the user password appended with the group of \000 grouping's.
Note the word "Decrypted" which confirms that the password entered in Wireshark is a match with that entered on the AAA client (for what that's worth).
I'm not sure if I suggested that this would confirm that the server and client were using the same shared secret. If I did, I miss-spoke. I think we would have to gauge the server's response to the attributes we see passed by the client.
The Wireshark decryption is much more dramatic with TACACS+ because the whole payload is encrypted.
My issue with your PPPoE is that I saw no "interface" on the router that is configured to perform such authentication. I do seem to recall a global authentication command with the PPP keyword perhaps. I have not attempted to do this, and am not sure whether the interfaces in your router will support this method. Perhaps someone else will weigh in with an opinion.
However, there are other mainstream authentication methods that I think you should investigate as well.
You could implement 802.1x on a switch so that a host has to authenticate before it can gain Layer 3 access to the LAN. Depending on the platform, you can download VLAN assignments and ACLs.
I believe the router also supports 802.1x, but that may determine whether a host can get "through" the router. I have not had cause to investigate 802.1x on the router. I may do so in the future to authorize access to IPsec tunnels.
The router is also likely to support Authentication Proxy. This feature intercepts a user's attempt to browse resources on the other side of the router. User specific ACLs can be downloaded to the router (from RADIUS) to control what resources a user can access.
I think you should:
1. Resolve the issue(s) with AAA logins on the router. It'll establish a baseline of functionality, and give you some short term joy.
2. Investigate whether PPPoE support exists on your router's interfaces.
3. Read up on 802.x and Authentication Proxy (docs on Cisco web site).
4. Decide which methods appeals to you.
5. Dive in.
I'd lose the self-deprecation. I don't think it will serve you well. If you're treated badly, move to a newsgroup where the participants display a higher level of emotional maturity. I don't think you will have an issue on the Cisco forums. Others would probably step in.
I'm going to be absent for several days, so if you don't receive any response, it will be for said reason.
Good luck.