IP Address for Serial Interface

[DanielBowen]

I have configured an E1 PRI controller for ISDN30 on a Cisco 3640, and need to configure the serial0/1:15 interface (D channel). I want to assign an IP address but do not know where to get the IP address from (LAN network number, made up address etc)

Any help would be great !

Thanks,

Daniel

 

[jevansau99]

daniel, please give more info. is this an internal router using a private address? how many IP numbers do you have from your ISP? you can't make up a public address but you can use anything in the

10.x.x.x/8 network
172.16.x.x/12 network
192.168.x.s/16 network

for your private use. "No hacker is worth missing a Dead concert for" - c.s.

 

[DanielBowen]

Ok, we have a 3640 router that is connected to 2 ISDN30 lines. The router is sitting within its own subnet inside our local area network. We have an entire class B address assigned to our organisation so that is not a problem. I have configured the controllers connected to the ISDN30 lines and just need to configure the IP address on the serial interfaces (D channels)

Is this enough info?

thanks,

 

[wybnormal]

Make a loopback address and then use the IP UNNUMBERED command to assign the loopback IP to the serial interface. Many use the ethernet for the source and it works but it is not stable as the ethernet interface can flap which would flap the serial port.

MikeS Find me at

http://www.packetattack.com

"Diplomacy; the art of saying 'nice doggie' till you can find a rock" Wynn Catlin

 

[DanielBowen]

Have tried the loopback, but it errors saying "cannot use self" !

Thanks for the help

 

[jevansau99]

mike is right, and i'm not sure why you're getting that error. i would not put the ip unnumbered on the serial though, instead putting it what IOS do you have? anyway, try doing this just to be thorough. its from a 3640 w/ 12.2(5):

conf t
int loopback0
ip address 192.168.1.1 255.255.255.0

then ...

interface Serial0/0:15
no ip address
encapsulation ppp
dialer rotary-group 0
dialer-group 1
isdn switch-type primary-net5
isdn incoming-voice modem
no fair-queue
no cdp enable


on your virtual-template 1 interface
ip unnumbered loopback0

put this same command on the group-async interface as well if you will be using isdn callout

then on your dialer0 interface for isdn calls in...

interface dialer0
ip address unnumbered

"No hacker is worth missing a Dead concert for" - c.s.

 

[DanielBowen]

ISDN-DIAL#sh run
Building configuration...

Current configuration : 1639 bytes
!
version 12.1
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname
!
enable secret
!
!
!
!
!
ip subnet-zero


!
isdn switch-type primary-net5
!
!
controller E1 0/0
pri-group timeslots 1-31
!
controller E1 0/1
pri-group timeslots 1-31
!
!
interface Loopback0
ip address 10.1.1.1 255.0.0.0
!
interface FastEthernet0/0
description *** VLAN 400 ***
ip address x.x.x.x
speed 100
full-duplex
!
interface Serial0/0:15
description *** D Channel for PRI E0 ***
no ip address
encapsulation ppp
isdn switch-type primary-net5
isdn incoming-voice modem
!
interface Serial0/1:15
description *** D Channel for PRI E1 ***
no ip address
encapsulation ppp
isdn switch-type primary-net5
isdn incoming-voice modem
!
interface Group-Async0
ip unnumbered FastEthernet0/0
encapsulation ppp
peer default ip address pool dialup
ppp authentication chap
group-range 33 62
!
interface Group-Async1
ip unnumbered FastEthernet0/0
dialer in-band
dialer rotary-group 0
group-range 65 94
!
interface Dialer0
no ip address
no cdp enable
!
interface Dialer1
no ip address
dialer pool 1
no cdp enable
!
router eigrp 1
network
no auto-summary
no eigrp log-neighbor-changes
!
ip classless
no ip http server
!
banner motd ^C
************************************
** This is the UEL Dial In Server **
** A^C
!
line con 0

transport input none
line 33 62
line 65 94
line aux 0
line vty 0 4

here is the config so far, please could you have a look and tell me where I am going wrong?

thanks very much for your help !

Daniel,

 

[jevansau99]

daniel - please substitute the config clips i posted into your current



also, change your loopback subnet mask to 255.255.255.0 i think this is why your getting an error. on a router, you can't have more than one interface in the same subnet/network. "No hacker is worth missing a Dead concert for" - c.s.

 

[DanielBowen]

Thanks very much for all your help - I now seem to have it working

Thanks again,

Daniel,