From: Kian Wah, Lai (kian_wah@qala.com.sg)
Date: Sun May 02 2004 - 13:00:05 GMT-3
Yep
Thx for that as well ;) think I need more practice on ISDN.
Regards,
Kian Wah, Lai
_____
From: Kenneth Wygand [mailto:KWygand@customonline.com]
Sent: Sunday, May 02, 2004 11:53 PM
To: Kian Wah Lai; William Chen; MMoniz; ccie2be; CCIE Canidate;
ccielab@groupstudy.com
Subject: RE: What is the best way to become ISDN smart
Kian,
Yes, this is exactly what should happen. Isn't it nice when things work the
way they should every once in a while? :)
<snip>
However, the route I'm watching does not reappear in the routing table.
Guess is due to no routing protocols running over ISDN.
</snip>
Yes, this is correct. You will have to advertise this route over the ISDN
circuit if you still want reachability to that network. For sake of
completeness, the way Dialer Watch works is at the end of each "Dialer
Idle-timeout", it checks the local routing table to see if the watched route
is in the table. If the route is not in the table, _or_ if it is in the
table but reachable only via the BRI interface, it resets the "Dialer
Idle-timeout". So, in practicality you must also make sure that the route
over the BRI circuit will be replaced with a route to that network via
another circuit once the primary link is up and functioning properly again.
If not, even when the primary link comes back up, if the BRI interface is
still the preferred route to the watched network, the "Dialer Idle-timeout"
will be reset and the ISDN link will never disconnect. So essentially you
have to make sure the ISDN link is the _least_ preferred method (highest AD,
or same AD and highest metric) to reach the watched route.
Picture this... R1 and R2 are connected via Frame Relay and ISDN. R1 is
watching R2's Ethernet interface network (192.168.10.0/24). OSPF is running
over Frame Relay, EIGRP is running over ISDN. When the ISDN circuit is
down, the routing table knows how to reach 192.168.10.0/24 via Frame Relay
(AD of OSPF = 110). The watched route goes down, ISDN kicks up and learns
of 192.168.10.0/24 via EIGRP (AD of EIGRP = 90). Frame Relay circuit comes
back up and installs 192.168.10.0/24 into OSPF database, but route never
reaches the IP routing table because there is already a route to that
network with a lower AD. End Result - ISDN link will never disconnect once
it is initially established.
Be careful!
Hope this helps,
Ken
-----Original Message-----
From: nobody@groupstudy.com on behalf of Kian Wah Lai
Sent: Sun 5/2/2004 10:52 AM
To: 'William Chen'; Kenneth Wygand; 'MMoniz'; 'ccie2be'; 'CCIE Canidate';
ccielab@groupstudy.com
Cc:
Subject: RE: What is the best way to become ISDN smart
Hi,
I checked the show dialer and it stated it dialed due to OSPF. I removed the
network statement in OSPF for ISDN and shut e0/0 down. This time it did not
dial.
I then use dialer map to map the network that I'm watching and shut down
e0/0 again. This time it dials and reason is due to dialer watch-list. 'Dial
reason: Dialing on watched route loss' However, the route I'm watching does
not reappear in the routing table. Guess is due to no routing protocols
running over ISDN.
So, the dialer map statement is actually needed :)
Regards,
Kian Wah Lai
-----Original Message-----
From: William Chen [mailto:kwchen@netvigator.com]
Sent: Sunday, May 02, 2004 9:16 PM
To: Kian Wah Lai; 'Kenneth Wygand'; 'MMoniz'; 'ccie2be'; 'CCIE Canidate';
ccielab@groupstudy.com
Subject: Re: What is the best way to become ISDN smart
Hi,
According to the configuration, I seems to me that you also run OSPF in
the ISDN interfaces. If the Ethernet interface is down, OSPF packets will be
triggered to send thru the ISDN interface, and if OSPF is included as
interesting, OSPF maybe the reason that triggers the call. Run the "show
dialer" to check the reason of dialing, it maybe not be casued by the dialer
watch.
Besides enough practice, I really suggest to read the chapters in DocCD
about ISDN and DDR, read it carefully, word by word. It is the best way to
become ISDN smart.
Best Regards,
William Chen
----- Original Message -----
From: "Kian Wah Lai" <kian_wah@qala.com.sg>
To: "'Kenneth Wygand'" <KWygand@customonline.com>; "'MMoniz'"
<ccie2002@tampabay.rr.com>; "'ccie2be'" <ccie2be@nyc.rr.com>; "'CCIE
Canidate'" <cisco@heartofdarknessstudios.com>; <ccielab@groupstudy.com>
Sent: Sunday, May 02, 2004 2:39 PM
Subject: RE: What is the best way to become ISDN smart
> I tested it just now and here is what I've found
> R1 connected to R2 via Ethernet and ISDN. R1 is having a loop back int
which
> I'll use it for dialer watch-list. The routers that I've used are the one
> with the real ISDN line. I didn't manage to try the one on PEC, think
there
> are some problems with the simulator (can't even dial through)
>
>
> R1:
> interface BRI0/0
> ip address 172.16.1.1 255.255.255.0
> encapsulation ppp
> ip ospf demand-circuit
> dialer map ip 172.16.1.2 broadcast <num>
> dialer load-threshold 255 either
> dialer-group 1
> isdn switch-type basic-net3
> no peer neighbor-route
> end
>
> R2:
> interface BRI0/0
> ip address 172.16.1.2 255.255.255.0
> encapsulation ppp
> dialer watch-disable 10
> dialer map ip 172.16.1.1 broadcast <num>
> dialer watch-group 1
> dialer-group 1
> isdn switch-type basic-net3
> no peer neighbor-route
> end
>
> r2(config)#int e0/0
> r2(config-if)#shut
> r2(config-if)#
> 01:38:54: %OSPF-5-ADJCHG: Process 1, Nbr 10.10.10.10 on Ethernet0/0 from
> FULL to DOWN, Neighbor Down: Interface down or detached
> 01:38:54: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0, TEI 110 changed
to
> up
> 01:38:55: %LINK-3-UPDOWN: Interface BRI0/0:1, changed state to up
> 01:38:56: %LINK-5-CHANGED: Interface Ethernet0/0, changed state to
> administratively down
> 01:38:56: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0/0:1,
changed
> state to up
> 01:38:57: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0/0,
> changed state to down
> 01:39:00: %LINK-3-UPDOWN: Interface BRI0/0:2, changed state to up
> 01:39:01: %LINEPROTO-5-UPDOWN: Line protocol on Interface BRI0/0:2,
changed
> state to up
> 01:39:01: %ISDN-6-CONNECT: Interface BRI0/0:1 is now connected to <num>
> 01:39:06: %ISDN-6-CONNECT: Interface BRI0/0:2 is now connected to unknown
>
> Thus, there is no need for dialer map statement. I tried putting it in and
> it still works the same way.
>
> Regards,
> Kian Wah Lai
>
>
>
> -----Original Message-----
> From: Kenneth Wygand [mailto:KWygand@customonline.com]
> Sent: Sunday, May 02, 2004 11:36 AM
> To: Kian Wah Lai; MMoniz; ccie2be; CCIE Canidate; ccielab@groupstudy.com
> Subject: RE: What is the best way to become ISDN smart
>
> Kian,
>
> A few things:
>
> 1) Yes, it is possible to bring up both channels through a single dial
> number. This is done through PPP Multilink and can only be done with PPP
> encapsulation (like you are using). You just need to add the command "PPP
> Multilink". Then you need to tell it _when_ you want the second channel
to
> kick up. This can be load-based (ppp multilink load-threshold [1-255]),
or
> automatic (ppp multilink links minimum 2). The reason this appears to
work
> with the "real" circuit could be because the second link will come up
> _without_ multilink in the following scenario. Picture R1 calls R2
through
> the first dial number. If R2 doesn't realize it can reach R1 over this
> link, it may use the second dial number to call R1 back. You will see
this
> if you "show isdn history". Check the direction (inbound or outbound) for
> each circuit connection (which router initiated the call).
>
> 2) The way you have this connection set up, R1 can never dial R2 for two
> reasons. The first reason is because there is no dial string associated
> with the dialer map. This is correct if you do not want R1 to ever dial
R2.
> However, you also do not have any interesting traffic defined.
Interesting
> traffic is used to reset the "idle-timeout" which, when expires, tears
down
> the connection. There is an "idle-timeout" on each side of the circuit -
in
> your case, there is an idle-timeout on both R1 and R2. When _either_ of
> these values on either side reaches 0, the circuit is torn down, period.
R1
> does not care what R2's idle-timeout value is - if R1's idle-timeout
reaches
> 0, it will tear the circuit down. Since you have not explicitly defined
the
> idle-timeout value, the default is 120 seconds. Anytime interesting
traffic
> is seen crossing the link, this value is reset to the configured value
(the
> default of 120 seconds in this case). However, you do not have any
> interesting traffic defined through the configuration of a "dialer-group
x"
> interface command and associated "dialer-list x" global command. You can
> either A) define interesting traffic across this link, B) set the
> idle-timeout value to a very high value like 9999 (I don't like this), or
C)
> disable the idle-timeout value on router A through the command "no dialer
> idle-timeout". My preference is choice C if you want Router B to make all
> the dialing and teardown decisions.
>
> 3) You are using dialer watch. For whichever route you are watching, you
> must have an associated "dialer-map" mapping to that network. Even though
> this is not listed as a required task in the Dialer Watch configuration
task
> list on the documentation CD, you will see it referenced in the notes
within
> the configuration examples:
>
>
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fdia
> l_c/fnsprt6/dcdbakdw.htm#19111
>
> HTH,
> Ken
>
> -----Original Message-----
> From: Kian Wah Lai [mailto:kian_wah@qala.com.sg]
> Sent: Sat 5/1/2004 10:48 PM
> To: Kenneth Wygand; 'MMoniz'; 'ccie2be'; 'CCIE Canidate';
> ccielab@groupstudy.com
> Cc:
> Subject: RE: What is the best way to become ISDN smart
>
>
>
> R1 - ISDN - R2, only r2 can call r1
> This config works with a real ISDN line, but can't work on the ISDN
> simulator on PEC. Another thing with PEC ISDN is that I only get to
> bring up
> the 1st channel. For basic-net3 (both labs are using this), no SPID
> are
> required and my friend told me one number will bring up both
> channel.
>
> R1:
> interface BRI0/0
> ip address 172.16.12.1 255.255.255.0
> encapsulation ppp
> dialer map ip 172.16.12.2 name r2 broadcast
> isdn switch-type basic-net3
> no peer neighbor-route
> ppp authentication chap
> end
>
> R2:
> interface BRI0/0
> ip address 172.16.12.2 255.255.255.0
> encapsulation ppp
> dialer map ip 172.16.12.1 name r1 broadcast <num>
> dialer watch-group 1
> dialer-group 1
> isdn switch-type basic-net3
> no peer neighbor-route
> ppp authentication chap
> end
>
> Regards,
> Kian Wah Lai
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> Of
> Kenneth Wygand
> Sent: Sunday, May 02, 2004 10:32 AM
> To: Kian Wah Lai; MMoniz; ccie2be; CCIE Canidate;
> ccielab@groupstudy.com
> Subject: RE: What is the best way to become ISDN smart
>
> Kian,
>
> Can you post your configurations and describe the problem you are
> having?
> Maybe we can help you! :)
>
> Ken
>
> -----Original Message-----
> From: nobody@groupstudy.com on behalf of Kian Wah Lai
> Sent: Sat 5/1/2004 9:11 PM
> To: 'MMoniz'; 'ccie2be'; 'CCIE Canidate';
> ccielab@groupstudy.com
> Cc:
> Subject: RE: What is the best way to become ISDN smart
>
>
>
> One thing I'm curious about, I keep having problem with ISDN
> simulator :(
> However, when I copy the same config to a router with real
> ISDN
> line, it
> works perfectly fine.
>
> Regards,
> Kian Wah Lai
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]
> On Behalf
> Of
> MMoniz
> Sent: Sunday, May 02, 2004 3:53 AM
> To: ccie2be; CCIE Canidate; ccielab@groupstudy.com
> Subject: RE: What is the best way to become ISDN smart
>
> Well another alternative is to become a gold member or other
> level
> with
> IPExpert and you will have access to NUMEROUS escenarios
> that will
> not only
> give you explanations but also the configs if you so choose
> to look
> at. All
> of them are
> CCIE level but they also have CCNA and NP level.
>
> This is inlcuded if you take like the VCLass or any other
> class I
> believe
> and it makes picking labs to do very simple.
>
> For instance if I only want to go over ISDN they have a few
> labs
> that are
> just ISDN but also many other complex routing labs that
> include
> ISDN.
>
> Not that I am suggesting that any of the other products out
> there
> are not
> quality, but to me being able to access via
> a "virtual" means is important to me. I want to be able to
> access
> labs no
> matter my physical location.
>
> But it still all boils down to the same thing!!!learn,
> practice
> practice
> practice
>
> just my opinion,
>
> mike
>
>
>
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On
> Behalf
> Of
> ccie2be
> Sent: Saturday, May 01, 2004 3:21 PM
> To: CCIE Canidate; ccielab@groupstudy.com
> Subject: Re: What is the best way to become ISDN smart
>
>
> My suggestion would be to get your hands on a large set of
> practice
> labs and
> practice the isdn portion of each one. After doing 20 to 40
> of
> these
> practice labs, you'll feel fairly confident of your ability
> to
> handle ccie
> level isdn config's. Of course, if there are other topics
> you want
> or need
> to practice, you'll find them covered in the practice labs
> as well.
>
> Lots of companies these days offer practice lab workbooks,
> but for
> my money,
> I think those from Internetwork Expert are the best. They
> include
> with
> their practice labs comprehensive explanations of their
> solution at
> no
> additional cost whereas IPExpert offers no explanation at
> all or
> just a
> superficial one at best.
>
> Each company I think also provides a sample lab you can
> download for
> free so
> you can decide based on your assessment of their sample lab.
>
> good luck
> ----- Original Message -----
> From: "CCIE Canidate" <cisco@heartofdarknessstudios.com>
> To: <ccielab@groupstudy.com>
> Sent: Saturday, May 01, 2004 12:05 PM
> Subject: What is the best way to become ISDN smart
>
>
> > Hi everyone!
> >
> > I know that there is a way more gray matter here than at
> my house.
> > Basically, I have all of the right gear and can understand
> the
> basics,
> > AND have already read a ton of Cisco documents, Kaslow's
> book, the
> CISCO
> > Press books, among others....and still am not sure how
> best to
> assemble
> > the most efficient configs required for CCIE level work.
> I want
> to get
> > the opinions of group members on what materials give me
> the "BEST"
> > crawl, walk, run steps, procedures, and examples of how to
> setup
> ISDN in
> > preparation for the lab.
> >
> > Thanks,
> >
> > ISDN challenged guy
> >
> >
>
> _______________________________________________________________________
> > Please help support GroupStudy by purchasing your study
> materials
> from:
> > http://shop.groupstudy.com
> >
> > Subscription information may be found at:
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>
>
>
> _______________________________________________________________________
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>
>
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