From: Chris Mott (cmott@xxxxxxxx)
Date: Tue Apr 17 2001 - 10:18:45 GMT-3
In real life, IMHO, I would never use the dial-backup command in the first
place! Floating statics and Dialer-watch work the real life stuff better
... consider the FR circuit whereby the PVC gets deleted, but power is still
supplied to the interface via the last-mile local loop ... you get Serial 0
Up/Down, which is _not_ enough to trigger the dial-backup ... also, lest we
forget, when a BRI interface is used as dial-backup, it is then incapable of
other uses as it is held strictly for that use ... of course all of this has
been mentioned before and can be found in the archives, so m'apolgie!
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Daniel C. Young
Sent: Friday, March 30, 2001 12:07 AM
To: 'Alan Basinger'; 'Devender Singh'; 'Groupstudy Lab'
Subject: RE: ISDN backup interface
Alan,
Thanks for your input. You brought up issues I had not considered.
Now if I may, an argument in defense of my position. My suggestions are,
first and foremost, for a lab application. Your concerns are quite valid for
real life scenarios. However, after giving this a bit more thought, I'm not
quite sure that I entirely agree with you, both from a technical and an
economical standpoint.
Even in real life, should the serial link go down (let's hope that it
doesn't) the ISDN line will only serve as a temporary solution. After all,
this is why a company would select an ISDN line over a (more expensive)
point-to-point backup link or even other (cheaper) broadband services
nowadays. Assuming that the serial line is quite stable, ISDN cost is a
non-issue in the long run (averaged per-month). If ISDN costs begin to rise,
this gives signals that perhaps the serial line carrier is not meeting SLA
agreements.
I agree with you, though, that the called router need not have a dialer
string. However, lenghtening the idle time will ensure that the link won't
flap in the event that line comes up for backup. Since we do not define
interesting traffic on the called router, the calling router is insured
total control over link connect/disconnect.
Daniel Young
Sr. Network Engineer
Internet Data Center
SBC Service Inc. - ITO
(949) 221-1928 Office
(714) 350-8945 Cell
ICQ# 109846891
-----Original Message-----
From: Alan Basinger [mailto:abasinge@swbell.net]
Sent: Thursday, March 29, 2001 9:24 PM
To: Daniel C. Young; 'Devender Singh'; 'Groupstudy Lab'
Subject: RE: ISDN backup interface
Daniel,
If you are using this as a backup and the call is going to be placed one way
only when the ser2 goes down then keep the interesting traffic on the called
router r2504 and remove the dial string so it will not initiate the call
ever but will keep the line up if it has data to send only after r2522
places the call because ser2 has failed. You want the call initiated from
the router that has the backup command on the interface correct?
Therefore there is no reason to have a dial string on the other end on
r2504, but there is a reason not to have and idle time as long as the sun is
in the sky. It is called long distance charges and even in some cases local
toll charges. For ISDN these can be sky high. (much more than a pots line).
DDR is the best solution for dial backup when done correctly because it only
brings the line up when there is data. ( Your mission Jim if you choose to
accept it is to design a very good dialer-list ). It is common to shorten
the idle time so that the line goes down sooner if there is no traffic. When
it costs 25 cents or more a minute to keep the line up and after one e-mail
message comes across your keeping the line up for 11 days or till the ser 2
comes back up even if there is no data? Sorry but my customers would kill me
and find a new engineer as well as phone company.
How about this scenario? The line comes up sends the packets and then goes
down till more interesting traffic is seen. Then the customer pays only for
data sent... Not trying to be rude just a little education on ISDN DDR and
the costs associated. Hope this helps....
Alan Basinger
Systems Engineer
SBC DataComm
Houston Texas
abasinge@swbell.net
| |
||| |||
.|||||. .|||||.
.:|||||||||:.:|||||||||:.
C i s c o S y s t e m s
Certified Gold Partner
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Daniel C. Young
Sent: Thursday, March 29, 2001 11:06 PM
To: 'Devender Singh'; 'Groupstudy Lab'
Subject: RE: ISDN backup interface
Devender,
Of course, you can disagree with me. The key here, of course, is to define a
REALLY long idle time on the called router, such as 2147483. This will keep
it up for 11 days without flapping, unless of course, the primary link goes
back up. In that case, the calling router will terminate the link. This is
what we want.
Does this make sense? I'd like to know what your thoughts are.
Daniel Young
Sr. Network Engineer
Internet Data Center
SBC Service Inc. - ITO
(949) 221-1928 Office
(714) 350-8945 Cell
ICQ# 109846891
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Devender Singh
Sent: Wednesday, March 28, 2001 11:41 PM
To: Daniel C. Young; 'Groupstudy Lab'
Subject: RE: ISDN backup interface
Daniel,
Can I disgree with you with what you going to write in your LBB. If other
side does no have interesting traffic, what happen after idle time out once
the link is up. This will cause the link to flap.
cheers
Devender Singh
BE(Hons), CCNP
IP Solution Specialist
-----Original Message-----
From: Daniel C. Young [mailto:danyoung99@mediaone.net]
Sent: Thursday, 29 March 2001 3:43
To: 'Groupstudy Lab'
Subject: RE: ISDN backup interface
Group,
Many thanks for the fantastic response! You guys are great.
Here's how I was able to resolve it:
-added 'broadcast' parameter to 'dialer map'
-added 'name r25XX' parameter to 'dialer map' (although I don't think that
this one was crucial.
Also, a couple of new tips I learned from the "Little Black Book" by
Rudenko:
-Dialed router should NOT have interested traffic defined. Otherwise, it
tries to bring the dialer interface up each time interesting traffic needs
to cross the dialup connection. Rudenko even suggests coding a 'dialer-list
# protocol ip DENY' on the counterpart router.
Again, thank you all.
Regards,
Daniel Young
Sr. Network Engineer
SBC Internet Data Center
ICQ# 109846891
*** First attempt: San Jose - June 13, 2001 ***
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
David Bader
Sent: Wednesday, March 28, 2001 10:22 AM
To: Groupstudy Lab; adiment@uswest.com
Subject: AW: ISDN backup interface
Hi Daniel
there are several issues to talk about. first you have to be aware that the
backup command only sets bri0 in backup mode, which means it comes up if the
serial dies. but you have to make sure your routing will work in this case.
and you have no routes for your backup interface.
--------------- 1.1.1.0/24
| routing table r2522: R 10.0.0.0/8 192.168.0.2
(120)
|.1 C 1.1.1.0/24
r2522---- .1 C 192.168.0.0/24
|.1 | *C 10.1.1.0/24
192.168.0.0/24 | | 10.1.1.0/24
| |
|.2 |
r2504---- .2 routing table r2504: R 1.0.0.0/8 192.168.0.1
(120)
|.1 C 192.168.0.0/24
| C 10.3.0.0/16
*C 10.1.1.0/24
ok, now to the picture. i think you end up with this routing table, without
the connected route with the *. it wouldn't have any effect if you use a
class C on your TR because RIP I by default does auto-summary and you cannot
turn it off. first you need the command broadcast to allow rip to run, when
the bri comes up. if your bri comes alive (serial goes down) the *routes are
created. and if you add a static route 10.3.0.0/16 10.1.1.2 to router r2522
this route would also appear in your table at this time. so, now you have a
route to 10.3.0.0 which is used on your backup interface. on the other side
you need off course a route 1.1.1.0/24 10.1.1.1 to provide a way back. hope
this works !!!
another thing, you have to provide the name of the remote router in your map
command, otherwise you will run into problems if you connect with more than
one channel. the used channels are remembered with the hostname of the
remote router.
wish you much success, let me know if it worked.
--dave
-----Ursprungliche Nachricht-----
Von: nobody@groupstudy.com [mailto:nobody@groupstudy.com]Im Auftrag von
adiment@uswest.com
Gesendet: Mittwoch, 28. Marz 2001 16:59
An: ccielab@groupstudy.com
Betreff: RE: ISDN backup interface
1. Source the ping from a lan interface on the originating router. If you
source it from the serial and it goes down it probably won't be sending a
ping.
2. Use a class C mask for T/R interface.
3. Rip will not work because there is no "broadcast" statement in your
dialer map command.
-----Original Message-----
From: Daniel C. Young [mailto:danyoung99@mediaone.net]
Sent: Wednesday, March 28, 2001 1:31 AM
To: ccielab@groupstudy.com
Subject: ISDN backup interface
Group,
I'm having problems getting an ISDN bri interface to backup a serial
interface. Here's the scenario:
r2522
| |
| ISDN (backup)
| |
r2504
Both routers run rip advertising all networks. I perform a continuous ping
>from to r2504's TR int via the serial interface. In the middle, I pull the
cable and the BRI ints are supposed to come up. Instead, I get:
Sending 1000, 100-byte ICMP Echos to 10.3.1.1, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.
03:25:21: %LINK-3-UPDOWN: Interface Serial2, changed state to down
03:25:22: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2, changed
state
to down..
03:25:26: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down
03:25:26: %LINK-3-UPDOWN: Interface BRI0:2, changed state to down
03:25:26: %LINK-3-UPDOWN: Interface BRI0, changed state to up
03:25:26: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 64 changed to up
03:25:26: ISDN BR0: TX -> INFORMATION pd = 8 callref = (null)
SPID Information i = '3840000001'
03:25:26: ISDN BR0: RX <- INFORMATION pd = 8 callref = (null)
ENDPOINT IDent i = 0x8181
03:25:26: ISDN BR0: Received .
EndPoint ID
03:25:26: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0, TEI 65 changed to up
03:25:26: ISDN BR0: TX -> INFORMATION pd = 8 callref = (null)
SPID Information i = '3840000002'
03:25:26: ISDN BR0: RX <- INFORMATION pd = 8 callref = (null)
ENDPOINT IDent i = 0x8282
03:25:26: ISDN BR0: Received EndPoint ID..........................
It just hangs here...now once, I plug the cable back in everything else
comes back up as normal:
03:35:21: %LINK-3-UPDOWN: Interface Serial2, changed state to up.
03:35:22: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2, changed
state
to up.........
03:35:41: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BRI0, TEI 64 changed to
down
03:35:41: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BRI0, TEI 65 changed to
down
03:35:41: %LINK-5-CHANGED: Interface BRI0, changed state to standby mode
03:35:41: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down
03:35:41: %LINK-3-UPDOWN: Interface BRI0:2, changed state to
down.!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!
Success rate is 85 percent (852/1000), round-trip min/avg/max = 28/28/152 ms
If I take off the backup commands on the serial interface, the router dials
just fine and everybody is happy, which leads me to believe that SPIDs and
phone numbers are OK.
Configs:
[r2522]
hostname r2522
!
username r2504 password 0 cisco
isdn switch-type basic-ni
!
interface Ethernet0
ip address 1.1.1.1 255.255.255.0
no ip directed-broadcast
no keepalive
!
interface Serial2
backup delay 5 20
backup interface BRI0
ip address 192.168.0.1 255.255.255.0
no ip directed-broadcast
clockrate 72000
!
interface BRI0
ip address 10.1.1.1 255.255.255.0
no ip directed-broadcast
encapsulation ppp
dialer idle-timeout 90
dialer map ip 10.1.1.2 384020
dialer load-threshold 1 outbound
dialer-group 1
isdn switch-type basic-ni
isdn spid1 3840000001 384000
isdn spid2 3840000002 384010
ppp authentication chap
ppp multilink
!
router rip
network 1.0.0.0
network 10.0.0.0
network 192.168.0.0
!
dialer-list 1 protocol ip permit
[r2504]
hostname r2504
!
username r2522 password 0 cisco
isdn switch-type basic-ni
!
interface Serial0
ip address 192.168.0.2 255.255.255.0
no ip directed-broadcast
no ip mroute-cache
no fair-queue
!
interface TokenRing0
ip address 10.3.1.1 255.255.0.0
no ip directed-broadcast
ring-speed 16
!
interface BRI0
ip address 10.1.1.2 255.255.255.0
no ip directed-broadcast
encapsulation ppp
dialer idle-timeout 90
dialer map ip 10.1.1.1 384000
dialer load-threshold 1 outbound
dialer-group 1
isdn switch-type basic-ni
isdn spid1 3840200001 384020
isdn spid2 3840200002 384030
ppp authentication chap
ppp multilink
!
router rip
network 10.0.0.0
network 192.168.0.0
!
dialer-list 1 protocol ip permit
Any advices? Thanks...
Daniel Young
Sr. Network Engineer
SBC Internet Data Center
ICQ# 109846891
*** First attempt: San Jose - June 13, 2001 ***
**NOTE** All LAB SWAP messages should now be sent to the
LAB SWAP Message board on groupstudy.com.
**NOTE** All LAB SWAP messages should now be sent to the
LAB SWAP Message board on groupstudy.com.
**NOTE** All LAB SWAP messages should now be sent to the
LAB SWAP Message board on groupstudy.com.
**NOTE** All LAB SWAP messages should now be sent to the
LAB SWAP Message board on groupstudy.com.
**NOTE** All LAB SWAP messages should now be sent to the
LAB SWAP Message board on groupstudy.com.
**NOTE** All LAB SWAP messages should now be sent to the
LAB SWAP Message board on groupstudy.com.
**NOTE** All LAB SWAP messages should now be sent to the
LAB SWAP Message board on groupstudy.com.
**Please read:http://www.groupstudy.com/list/posting.html
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:29:47 GMT-3