Solved

Authenticating PPP users while keeping them out of IOS on a Cisco router

Posted on 2008-10-23
3
190 Views
Last Modified: 2013-12-14
We authenticate PPP users on a Cisco router using a local username and password list. To my horror, recently I realized that any PPP user could could open an SSH or telnet session to the router with full administrative privileges using their PPP username and password.

As a temporary fix I have put in some ACL's to prevent access to port 22 and 23 from anywhere except admin IP addresses. However obviously now I am looking to put in a more permanent and secure solution without the hassle of having to install a separate RADIUS authentications server. I would like to keep maintaining a PPP username and password list on the router without compromising security.

The relevant router config sections is attached

!                                                                               
line con 0                                                                      
line aux 0                                                                      
line vty 0 4                                                                    
 privilege level 15                                                             
 transport input telnet ssh                                                     
!                                                                               
 
!                                                                               
aaa new-model                                                                   
!                                                                               
!                                                                               
aaa authentication ppp default local                                               
!                                     
 
!                                                                               
username admin secret 5 $8$NCxxxxxxxxxxxx
username pppuser1 password 0 secret123                             
archive                                                                         
 log config                                                                     
  hidekeys                                                                      
!

Open in new window

0
Comment
Question by:Fo_Shizzle
  • 2
3 Comments
 
LVL 10

Expert Comment

by:kyleb84
ID: 22792510
Local RADIUS server...

The Cisco itself can be the RADIUS server as well...

aaa new-model
aaa authentication login default radius local
aaa authentication login no_radius enable
aaa authentication ppp default if-needed radius
aaa authorization network radius
aaa accounting exec start-stop radius
aaa accounting network start-stop radius
---
radius-server local
 nas [VLAN1IP] key [key]
 group usersgrp
  user user1 nthash password1 group usersgrp
  user user2 nthash password2 group usersgrp
!
radius-server host [VLAN1IP] auth-port 1812 acct-port 1813 key [key]
radius-server retransmit 3
radius-server attribute 32 include-in-access-req format %h
radius-server authorization permit missing Service-Type
radius-server vsa send accounting

-------------

The above authenticates ppp users via RADIUS username/passwords, and console access by the local password database.

0
 
LVL 10

Accepted Solution

by:
kyleb84 earned 500 total points
ID: 22792570
Hmm should change the line:

"aaa authentication login default radius local"
to
"aaa authentication login default local"

and:
line vty 0 4
 login authentication default
0

Featured Post

Netscaler Common Configuration How To guides

If you use NetScaler you will want to see these guides. The NetScaler How To Guides show administrators how to get NetScaler up and configured by providing instructions for common scenarios and some not so common ones.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Problem Description:   Couple of months ago we upgraded the ADSL line at our branch office from Home to Business line. The purpose of transforming the service to have static public IP’s. We were in need for public IP’s to publish our web resour…
Getting hacked is no longer a matter or "if you get hacked" — the 2016 cyber threat landscape is now titled "when you get hacked." When it happens — will you be proactive, or reactive?
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

832 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question