Configuring modems via Cisco AS

1
Configuring modems via Cisco AS

• telnet x.x.x.x 200y
• x.x.x.x - IP address of the AS
• y - line number to which the modem is connected
• Use AT commands
• Finish with CTRL x
• clear line 1

2
Cisco AS - creating usernames

• username row1pc1 password row1pc1
• username row1pc2 password row1pc2
• ...

3
Cisco AS - Physical Layer Commands

• line 1
• login local
• modem inout
• stopbits 1
• speed 115200
• flowcontrol hardware
• autohangup

4
Cisco AS - Higher Layer commands

• Interface async 1
• ip unnumbered Ethernet0
• ip tcp header-compression passive
• async defaul IP address x.x.x.x
• async dynamic address
• async mode interactive

5
Cisco AS - Routing

• ip route 0.0.0.0 0.0.0.0 161.53.75.1

6
Connecting Dialogue - Dial up host

• Username username
• Password password
• promptgttelnet ltIP addressgt
• or
• promptgtppp default

7
Connecting Dialogue - Dial up LAN

• Username username
• Password password
• promptgtppp ltdedicated IP addressgt

8
PAP Authentication

• int async 1
• encapsulation ppp
• ppp authentication pap

9
CHAP Authentication

• int async 1
• encapsulation ppp
• ppp authentication chap

10
Debugging commands

• debug modem
• debug ppp negotiation
• debug ppp authentication

11
Cisco AS - TACACS Configuration

• tacacs-server host ltIP addressgt
• tacacs-server key key
• aaa new-model
  
• aaa authentication local-override
  
• aaa authentication login default tacacs
  
• aaa authentication ppp default if-needed tacacs

12
Cisco AS - TACACS Configuration

• aaa authorization exec local if-authenticated
  
• aaa authorization commands 0 none
  
• aaa authorization network tacacs
  
• aaa accounting exec start-stop tacacs
  
• aaa accounting network start-stop tacacs
  
• aaa accounting system start-stop tacacs
  

13
Debugging commands

• debug aaa authentication
• debug aaa authorisation

14
Tacacs Server

• TACACS demon
• /usr/sbin/tacacs -C tac.conf
• Man page
• man tacacs
• User guide
• /root/tacacs.ug

15
Tacacs Server Configuration - terminal user
key secret user terminal global cleartext
terminal service exec autocmd "telnet
161.53.74.11"
16
TACACS - PPP user
user ppp-dynamic global cleartext ppp
service ppp protocol ip user
ppp-static global cleartext ppp service
ppp protocol ip addr 161.53.75.254
17
TACACS - LAN user
user ppp-LAN global cleartext ppp-lan
service ppp protocol ip addr
161.53.75.253 route "192.168.20.0
255.255.255.0 161.53.75.253"