From: Matthew Seppeler (Matt.Seppeler@InetX.com)
Date: Sun Oct 17 2004 - 13:58:25 GMT-3
ISDN is probably one of the most quirky things I had the pleasure of
dealing with in preparing for the R&S exam. However, thanks to the help
of the Brian McGahan with Internetwork Experts and the Mock Lab class I
took the other week, I've settled into an almost foolproof way of
minimizing the headaches of configuring ISDN. If you are in the final
stretch in preparing for the lab, it's a class well worth the money.
The basis for this email is to point out a case where it was required to
reload the ISDN switch in getting ISDN layer 2 working. Below are the
steps I followed in configuring ISDN with the minimal configuration
needed to get to this point of configuration:
1) Shut down the BRI interface.
2) Assigned an IP address to the interface.
3) Assigned the ISDN switch type to the interface.
4) Assigned the spids if required. In this case, yes as we are
using basic-ni.
5) No shut on the BRI interface.
6) Verified Layer 2 connectivity with the show ISDN status. You
should see "multiple frame stabled" with "valid" spids.
7) Run the command "isdn test call int b0/0 string" to test that
the circuit comes up.
If after running all these steps, this will verify that the ISDN switch
is indeed ok. Any further issues with ISDN will be a result of the
config as extra stuff is added.
Well, it looks like I found one of those rare cases that the ISDN switch
is to blame. Nope, it was not due to wrong spids or switch type. Even
after I did a reload on the router, I was still not able to get ISDN
layer 2 connectivity up and working with the basic step followed above.
The error message when doing a "show isdn status" shows that the Layer 2
status shows as "ESTABLISH_AWAITING_TEI" or "await establishment" along
with invalid spids. I kid you not, all I had to do to resolve this
issue was to reload the ISDN switch. Fortunately, the rack I was on
gives you access to reload the ISDN switch. This is not my own rack to
add. It was rented from RackTimeRentals and is one of the reasons why I
like using their racks. Great job Bill with providing this feature for
our use!
Being that I've run into this problem before, I was quick enough to log
my config for my configuration steps as well as steps taken to resolve
this issue. Below is input if you wish to review in further detail:
Rack2R5(config)#int b0/0
Rack2R5(config-if)#shut
ip address 139.2.45.5 255.255.255.0
isdn switch-type basic-ni
isdn spid1 0835866201 8358662
isdn spid2 0835866401 8358664
Rack2R5#sh isdn status
Global ISDN Switchtype = basic-ni
ISDN BRI0/0 interface
dsl 0, interface ISDN Switchtype = basic-ni
Layer 1 Status:
ACTIVE
Layer 2 Status:
TEI = 255, Ces = 1, SAPI = 0, State = ESTABLISH_AWAITING_TEI
TEI Not Assigned, ces = 1, state = 3(await establishment)
spid1 configured, spid1 NOT sent, spid1 NOT valid
TEI Not Assigned, ces = 2, state = 1(terminal down)
spid2 configured, spid2 NOT sent, spid2 NOT valid
Layer 3 Status:
0 Active Layer 3 Call(s)
CCB:callid=0, sapi=0, ces=1, B-chan=0, calltype=INTERNAL (BR0/0)
SPC Call
Active dsl 0 CCBs = 1
The Free Channel Mask: 0x80000003
Rack2R5#show run | begin BRI
interface BRI0/0
ip address 139.2.45.5 255.255.255.0
isdn switch-type basic-ni
isdn spid1 0835866201 8358662
isdn spid2 0835866401 8358664
!
!
!
Rack2R5#c
Enter configuration commands, one per line. End with CNTL/Z.
Rack2R5(config)#int b0/0
Rack2R5(config-if)#shut
Rack2R5(config-if)#
*Mar 1 00:06:51.435: %LINK-5-CHANGED: Interface BRI0/0, changed state
to administratively down
Rack2R5(config-if)#
Rack2R5(config-if)#
Rack2R5(config-if)#
Rack2R5(config-if)#
Rack2R5(config-if)#
Rack2R5(config-if)#
Rack2R5(config-if)#no shut
Rack2R5(config-if)#
*Mar 1 00:06:55.599: %LINK-3-UPDOWN: Interface BRI0/0:1, changed state
to down
*Mar 1 00:06:55.599: %LINK-3-UPDOWN: Interface BRI0/0:2, changed state
to down
*Mar 1 00:06:55.651: %LINK-3-UPDOWN: Interface BRI0/0, changed state to
up
Rack2R5(config-if)#
Rack2R5(config-if)#
Rack2R5(config-if)#
Rack2R5(config-if)#^Z
*Mar 1 00:06:58.507: %SYS-5-CONFIG_I: Configured from console by
console
Rack2R5#sh isdn status
Global ISDN Switchtype = basic-ni
ISDN BRI0/0 interface
dsl 0, interface ISDN Switchtype = basic-ni
Layer 1 Status:
ACTIVE
Layer 2 Status:
TEI = 255, Ces = 1, SAPI = 0, State = ESTABLISH_AWAITING_TEI
TEI Not Assigned, ces = 1, state = 3(await establishment)
spid1 configured, spid1 NOT sent, spid1 NOT valid
TEI Not Assigned, ces = 2, state = 1(terminal down)
spid2 configured, spid2 NOT sent, spid2 NOT valid
Layer 3 Status:
0 Active Layer 3 Call(s)
CCB:callid=0, sapi=0, ces=1, B-chan=0, calltype=INTERNAL (BR0/0)
SPC Call
Active dsl 0 CCBs = 1
The Free Channel Mask: 0x80000003
Rack2R5#wr
Building configuration...
[OK]
Rack2R5#relaod
Translating "relaod"
Translating "relaod"
% Unknown command or computer name, or unable to find computer address
Rack2R5#reload
Proceed with reload? [confirm]
*Mar 1 05:10:12.826: %SYS-5-RELOAD: Reload requested by console.
System Bootstrap, Version 11.1(19)AA, EARLY DEPLOYMENT RELEASE SOFTWARE
(fc1)
Copyright (c) 1998 by cisco Systems, Inc.
C3600 processor with 131072 Kbytes of main memory
Main memory is configured to 64 bit mode with parity disabled
program load complete, entry point: 0x80008000, size: 0x1342300
Self decompressing the image :
########################################################################
#############################
########################################################################
############################################################
################### [OK]
Smart Init is disabled. IOMEM set to: 15
Using iomem percentage: 15
Restricted Rights Legend
Use, duplication, or disclosure by the Government is
subject to restrictions as set forth in subparagraph
(c) of the Commercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 and subparagraph
(c) (1) (ii) of the Rights in Technical Data and Computer
Software clause at DFARS sec. 252.227-7013.
cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706
Cisco Internetwork Operating System Software
IOS (tm) 3600 Software (C3640-JK9O3S-M), Version 12.2(15)T13, RELEASE
SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2004 by cisco Systems, Inc.
Compiled Wed 16-Jun-04 05:33 by hqluong
Image text-base: 0x60008950, data-base: 0x62046000
This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.
A summary of U.S. laws governing Cisco cryptographic products may be
found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html
If you require further assistance please contact us by sending email to
export@cisco.com.
cisco 3640 (R4700) processor (revision 0x00) with 111616K/19456K bytes
of memory.
Processor board ID 10528867
R4700 CPU at 100Mhz, Implementation 33, Rev 1.0
Bridging software.
X.25 software, Version 3.0.0.
SuperLAT software (copyright 1990 by Meridian Technology Corp).
TN3270 Emulation software.
Basic Rate ISDN software, Version 1.1.
2 Ethernet/IEEE 802.3 interface(s)
1 Serial network interface(s)
1 ISDN Basic Rate interface(s)
DRAM configuration is 64 bits wide with parity disabled.
125K bytes of non-volatile configuration memory.
24576K bytes of processor board System flash (Read/Write)
Press RETURN to get started!
*Mar 1 00:00:04.175: %LINEPROTO-5-UPDOWN: Line protocol on Interface
VoIP-Null0, changed state to up
*Mar 1 00:00:15.883: %QUICC-1-UNEXPECTED_INTERRUPT: Quicc(0),
Unexpected modem-signal interrupt
*Mar 1 00:00:16.083: %LINK-3-UPDOWN: Interface Serial0/0, changed state
to up
*Mar 1 00:00:16.087: %LINK-3-UPDOWN: Interface Ethernet0/0, changed
state to up
*Mar 1 00:00:16.087: %LINK-3-UPDOWN: Interface Ethernet1/0, changed
state to up
*Mar 1 00:00:17.175: %SYS-5-CONFIG_I: Configured from memory by console
*Mar 1 00:00:17.419: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Serial0/0, changed state to up
*Mar 1 00:00:17.419: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Ethernet0/0, changed state to up
*Mar 1 00:00:17.419: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Ethernet1/0, changed state to up
*Mar 1 00:00:17.419: %LINK-3-UPDOWN: Interface BRI0/0, changed state to
up
*Mar 1 00:00:18.587: %LINEPROTO-5-UPDOWN: Line protocol on Interface
BRI0/0, changed state to down
*Mar 1 00:00:19.679: %SYS-5-RESTART: System restarted --
Cisco Internetwork Operating System Software
IOS (tm) 3600 Software (C3640-JK9O3S-M), Version 12.2(15)T13, RELEASE
SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2004 by cisco Systems, Inc.
Compiled Wed 16-Jun-04 05:33 by hqluong
*Mar 1 00:00:19.687: %SNMP-5-COLDSTART: SNMP agent on host Rack2R5 is
undergoing a cold start
*Mar 1 00:00:19.719: %LINK-3-UPDOWN: Interface Virtual-Access1, changed
state to up
*Mar 1 00:00:20.719: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Virtual-Access1, changed state to up
Rack2R5#
Rack2R5#sh isdn statu
Global ISDN Switchtype = basic-ni
ISDN BRI0/0 interface
dsl 0, interface ISDN Switchtype = basic-ni
Layer 1 Status:
ACTIVE
Layer 2 Status:
Layer 2 NOT Activated
TEI Not Assigned, ces = 1, state = 3(await establishment)
spid1 configured, spid1 NOT sent, spid1 NOT valid
TEI Not Assigned, ces = 2, state = 1(terminal down)
spid2 configured, spid2 NOT sent, spid2 NOT valid
Layer 3 Status:
TWAIT timer active
0 Active Layer 3 Call(s)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0x80000003
Rack2R5#sb BR
interface BRI0/0
no ip address
isdn switch-type basic-ni
isdn spid1 0835866201 8358662
isdn spid2 0835866401 8358664
!
Rack2R5#
Rack_Time_12>2
[Resuming connection 2 to apc ... ]
User Name : xxx
Password : *****
American Power Conversion Web/SNMP Management Card AOS
v3.0.3
(c) Copyright 2000 All Rights Reserved MasterSwitch APP
v2.2.0
------------------------------------------------------------------------
-------
Name : Rack Time Rentals Rack8 Date : 10/17/2004
Contact : support@racktimerentlas.co Time : 08:18:48
Location : Valley of the Sun Up Time : 0 Days 3 Hours 47
Minutes
Status : P+ N+ A+ User : Outlet User
MasterSwitch : Serial Communication Established
------- Control Console
-------------------------------------------------------
1- Device Manager
2- Network
3- System
4- Logout
<ESC>- Main Menu, <ENTER>- Refresh
> 1
------- Device Manager
--------------------------------------------------------
1- R1,R2 ON
2- R3 ON
3- R4 ON
4- R5 ON
5- R6 ON
6- CAT1,CAT2 ON
7- ISDN Switch ON
8- ALL Accessible Outlets
<ESC>- Back, <ENTER>- Refresh
> 7
------- ISDN Switch
-----------------------------------------------------------
Name : ISDN Switch
State: ON
1- Immediate On
2- Immediate Off
3- Immediate Reboot
4- Delayed On
5- Delayed Off
6- Delayed Reboot
7- Cancel
?- Help, <ESC>- Back, <ENTER>- Refresh
> 3
-----------------------------------------------------------------------
Immediate Reboot
This command will immediately shutdown
outlet 7 named ISDN Switch, delay for 05 Seconds,
and then restart.
Enter 'YES' to continue or <ENTER> to cancel : YES
Command successfully issued.
Press <ENTER> to continue...
------- ISDN Switch
-----------------------------------------------------------
Name : ISDN Switch
State: OFF*
1- Immediate On
2- Immediate Off
3- Immediate Reboot
4- Delayed On
5- Delayed Off
6- Delayed Reboot
7- Cancel
?- Help, <ESC>- Back, <ENTER>- Refresh
>
Rack_Time_12>1
[Resuming connection 1 to r5 ... ]
Rack2R5#
Rack2R5#
Rack2R5#sh isdn stat
Global ISDN Switchtype = basic-ni
ISDN BRI0/0 interface
dsl 0, interface ISDN Switchtype = basic-ni
Layer 1 Status:
DEACTIVATED
Layer 2 Status:
Layer 2 NOT Activated
TEI Not Assigned, ces = 1, state = 3(await establishment)
spid1 configured, spid1 NOT sent, spid1 NOT valid
TEI Not Assigned, ces = 2, state = 1(terminal down)
spid2 configured, spid2 NOT sent, spid2 NOT valid
Layer 3 Status:
0 Active Layer 3 Call(s)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0x80000003
Rack2R5#
Rack2R5#
*Mar 1 00:08:24.143: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0, TEI
122 changed to up
*Mar 1 00:08:24.275: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0, TEI
123 changed to up
Rack2R5#sh isdn stat
Global ISDN Switchtype = basic-ni
ISDN BRI0/0 interface
dsl 0, interface ISDN Switchtype = basic-ni
Layer 1 Status:
ACTIVE
Layer 2 Status:
TEI = 122, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
TEI = 123, Ces = 2, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
TEI 122, ces = 1, state = 5(init)
spid1 configured, spid1 sent, spid1 valid
Endpoint ID Info: epsf = 0, usid = 2, tid = 1
TEI 123, ces = 2, state = 5(init)
spid2 configured, spid2 sent, spid2 valid
Endpoint ID Info: epsf = 0, usid = 4, tid = 1
Layer 3 Status:
0 Active Layer 3 Call(s)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0x80000003
Total Allocated ISDN CCBs = 0
Rack2R5#
I have to go against the grain here when proctors and others lab say
that in very rare cases, the ISDN issues are due to the ISDN switch
itself. True, most of the time it's due to user configuration issues.
However, I've managed to reproduce (not on purpose I would add) this
particular scenario several times over the last couple of months of
doing various labs and on different racks as well. I would estimate
about 5% of the time, which to me does not equate to very rare cases.
Not sure what the problem was on the ISDN switch. Maybe a different
switch type was configured on it from someone doing a previous lab or
maybe the ISDN interface on the router was shut down abruptly such as
the shut command I issued on the BRI0/0 interface as the 1st step taken
in ISDN configuration.
As I do not consider myself to be an ISDN guru, my question goes out to
those who know this technology inside and out. Did I take or miss any
steps I could have taken to have eliminated this issue and not have
required a reload of the ISDN switch? If not and the methodology I
followed was of best practice, would it be a fair question to ask the
proctor before the exam begins if they have reloaded the ISDN switch?
Troubleshooting this issue wasted about 20 minutes before the ISDN
switch was reloaded to resolve this issue. It typically takes me about
2-3 minutes in getting Layer 2 up with ISDN. As you won't have access
to the ISDN switch in the lab, you will probably need to take even more
time trying to convince the proctor to reload the ISDN switch. After
wining this battle, I'm sure they will give you all that time back you
spent troubleshooting. NOT!!!! As supposedly rare a case that it may
seem that would require a reload of the ISDN switch, I think it would be
fair to ask the proctor to take that extra step in better preparing the
lab to potentially reduce issues with faulty hardware in the lab.
Although, I'm sure this request will go unanswered because hardware
issues are so rare these days.... I just hope I'm not one of those that
will experience this rare ISDN issue in the real lab that could be so
easy to potentially thwart before one even begins the lab. Any
thoughts?
Matt Seppeler
Email: mseppeler@inetx.com
This archive was generated by hypermail 2.1.4 : Sat Nov 06 2004 - 17:11:48 GMT-3