5 Cisco NAS equipment has become quite popular of late, but being Cisco
6 equipment running IOS, the configuration can be a bit non-obvious to the
7 unfamiliar. This document aims to describe the most common configuration
8 options to make your Ciscos interoperate with radius as you would expect a
9 well-behaved NAS to do.
13 For Cisco 12.x ( 12.0 and 12.1 ), the following AAA configuration directives
17 aaa authentication login default group radius local
18 aaa authentication login localauth local
19 aaa authentication ppp default if-needed group radius local
20 aaa authorization exec default group radius local
21 aaa authorization network default group radius local
22 aaa accounting delay-start
23 aaa accounting exec default start-stop group radius
24 aaa accounting network default start-stop group radius
27 this configuration works very well with most radius servers. One of the more
28 important configurations is:
30 aaa accounting delay-start
32 This directive will delay the sending of the Accounting Start packet until
33 after an IP address has been assigned during the PPP negotiation process.
34 This will supersede the need to enable the sending of "Alive" packets as
35 described below for IOS versions 11.x
37 *NOTE* with the above it will use the radius server to authenticate
38 your inbound 'telnet' connections. You will need to create an entry
39 in your users file similar to the following to allow access:
41 !root User-Password == "somepass"
42 Service-Type = NAS-Prompt-User
44 This will let a user in for the first level of access to your Cisco. You
45 will still need to 'enable' ( using the locally configured enable secret )
46 to perform any configuration changes or anything requiring a higher level
47 of access. The username '!root' was used as an example here, you can make
48 this any username you want, of course.
50 1.1 Unique Acct-Session-Id's
52 From: http://isp-lists.isp-planet.com/isp-australia/0201/msg05143.html
54 Just a note to all cisco ISPs out there who want RFC2866 compliance need to
55 enable the hidden command 'radius-server unique-ident <n>'
57 Minimum IOS: 12.1(4.1)T.
59 Acct-Session-Id should be unique and wrap after every 256 reboots.
61 You must reboot after entering this command to take effect. If not, you
62 will observe after 10 minutes
63 of entering this command, the following message.
65 %RADIUS-3-IDENTFAIL: Save of unique accounting ident aborted.
70 For Cisco 11.1, you normally use
73 aaa authentication ppp radppp if-needed radius
74 aaa authorization network radius none
75 aaa accounting network wait-start radius
77 to get the Cisco to talk to a radius server.
79 With IOS 11.3, you need to add:
81 aaa accounting update newinfo
83 If you want the IP address of the user to show up in the radutmp file
84 (and thus, the output of "radwho").
86 This is because with IOS 11.3, the Cisco first sends a "Start" accounting
87 packet without the IP address included. By setting "update newinfo" it
88 will send an account "Alive" packet which updates the information.
91 Also you might see a lot of "duplicates" in the logfile. That can be
94 aaa accounting network wait radius
95 radius-server timeout 3
98 To enable the Ascend style attributes (which we do NOT recommend!)
100 radius-server host X.Y.Z.A auth-port 1645 acct-port 1646 non-standard
102 To disable the Ascend style attributes (which is a VERY good idea!):
104 radius-server host X.Y.Z.A auth-port 1645 acct-port 1646
106 To see Cisco-AVPair attributes in the Cisco debugging log:
108 radius-server vsa accounting
110 4. Cisco 36xx & 26xx, keeping the NAS IP static
112 The Cisco 36/26 by default selects (it seems at random) any IP address
113 assigned to it (serial, ethernet etc.) as it's RADIUS client source
114 address, thus the access request may be dropped by the RADIUS server,
115 because it can not verify the client. To make the cisco box always use
116 one fixed address, add the following to your configuration:
118 ip radius source-interface Loopback0
120 and configure the loopback interface on your router as follows:
123 ip address 192.168.0.250 255.255.255.255
125 Use a real world IP address and check the Cisco documentation for why
126 it is a good idea to have working loopback interface configured on
129 If you don't want to use the loopback interface of course you can set
130 the source-interface to any interface on your Cisco box which has an
136 Original - Alan DeKok <aland@ox.org>
137 12.x Info - Chris Parker <cparker@starnetusa.net> 2000-10-12
141 For more information, the following page on Cisco's web site may help:
143 http://www.cisco.com/univercd/cc/td/doc/product/access/acs_serv/vapp_dev/vsaig3.htm