Saturday 20 September 2008

How to simulate ISDN Back To Back Configuration POTS Dial-Peers?

Connect two routers back-to-back style with cross over cable. Define switch type lets say qsig, then framing, line code, clock source, pri groups, user side, network side. (mean while forget about IP networks).

Here is one basic sample config, see how direct-indward-dial works, try some show and debug commands show isdn status, debug q931and q921 to see call set up signaling stuff.

(ISDN PRI Back To Back Configuration_Pots Dial-Peers)

USER SIDE CONFIGURATION
------------------------------
R1_3640#sh run
!
isdn switch-type primary-qsig
!
controller T1 1/0
framing esf
linecode b8zs
pri-group timeslots 1-4,24
!
interface Serial1/0:23
no ip address
encapsulation hdlc
isdn switch-type primary-qsig
isdn incoming-voice voice
no cdp enable
!
voice-port 1/0:23
!
voice-port 3/0/0
!
dial-peer voice 1111 pots
destination-pattern 1111
port 3/0/0
!
dial-peer voice 2222 pots
destination-pattern 2222
direct-inward-dial
port 1/0:23
forward-digits all

-------------------------------
NETWORK SIDE CONFIGURATION
-------------------------------
R2_3725#sh run
!
isdn switch-type primary-qsig
!
controller T1 1/0
framing esf
clock source internal
linecode b8zs
pri-group timeslots 1-4,24
!
interface Serial1/0:23
no ip address
isdn switch-type primary-qsig
isdn protocol-emulate network
isdn incoming-voice voice
no cdp enable
!
voice-port 1/0:23
!
voice-port 2/0/0
!
dial-peer voice 2222 pots
destination-pattern 2222
port 2/0/0
!
dial-peer voice 1111 pots
destination-pattern 1111
direct-inward-dial
port 1/0:23
forward-digits all

Friday 19 September 2008

How to set up a Cisco router to act as an NTP server?

Step 1 Log in to the router.

Step 2 Enter configuration mode:

router# configure terminal

Step 3 Create the key ID and key value:

router(config)# ntp authentication-key key_ID md5 key_value

The key ID can be a number between 1 and 65535. The key value is text (numeric or character). It is encrypted later.

Example:

router(config)# ntp authentication-key 100 md5 attack


Note The sensor only supports MD5 keys.

Note Keys may already exist on the router. Use the show running configuration command to check for other keys. You can use those values for the trusted key in Step 4.
Step 4 Designate the key you just created in Step 3 as the trusted key (or use an existing key):

router(config)# ntp trusted-key key_ID

The trusted key ID is the same number as the key ID in Step 3.

Example:

router(config)# ntp trusted-key 100

Step 5 Specify the interface on the router that the sensor will communicate with:

router(config)# ntp source interface_name

Example:

router(config)# ntp source FastEthernet 1/0

Step 6 Specify the NTP master stratum number to be assigned to the sensor:

router(config)# ntp master stratum_number

Example:

router(config)# ntp master 6

The NTP master stratum number identifies the server's relative position in the NTP hierarchy. You can choose a number between 1 and 15.