From: john matijevic (matijevi@bellsouth.net)
Date: Sun Aug 08 2004 - 12:01:24 GMT-3
Hello Scott,
The default route is installed per Cisco doc.
"A Level 1/Level 2 router that is attached to another area will set the
"attached bit" in its Level 1 LSP; all the Level 1 ISs in an area will
get a copy of this LSP and know where to forward packets to destinations
outside the area. If the routers are running Integrated IS-IS, a default
IP route will automatically be installed in the Level 1 routers pointing
toward the nearest Level 1/Level 2 router that originally set the
attached bit in its Level 1 LSP. A Level 1/Level 2 router that is not
attached to another area can also detect that a Level 2-only neighbor is
attached to another area and set the "attached bit" on behalf of this
Level 2-only neighbor."
I think the point of the question was if that using the command default
information originate was necessary to install a default route. And if
the default route being installed was normal behavior. I am just trying
to help the individual. Unlike other companies, I don't focus on
attacking other individuals. I focus on solutions. I don't have to take
the exam. It is Kaloyan who has to take the exam. So it is important
that he understands why the default route appears in the routing table.
Here is the link for more information:
http://www.cisco.com/en/US/tech/tk365/tk381/technologies_white_paper0918
6a00800a3e6f.shtml
Team, if anyone else has any trouble understanding this, please let me
know.
:) Again im not here to debate, I don't like to see a lot of threads, im
here to help.
Sincerely,
John Matijevic, CCIE #13254, MCSE, CNE, CCEA
Network Consultant
Hablo Espanol
305-321-6232
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Scott Morris
Sent: Sunday, August 08, 2004 10:42 AM
To: 'john matijevic'; k_kaloianov@eircom.net; ccielab@groupstudy.com
Subject: RE: isis and ATT bit=1
Actually, the default route is not "sent" at all. The ATT bit indicates
connection to an outside area. As soon as L1 routers see routes with
the
ATT bit set, they will create a default route pointing to the router
that
sent the ATT-bit routes.
HTH,
Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713,
CISSP,
JNCIP, et al.
IPExpert CCIE Program Manager
IPExpert Sr. Technical Instructor
swm@emanon.com/smorris@ipexpert.net
http://www.ipexpert.net
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
john
matijevic
Sent: Sunday, August 08, 2004 9:54 AM
To: k_kaloianov@eircom.net; ccielab@groupstudy.com
Subject: RE: isis and ATT bit=1
Hello Kaloyan,
What you are seeing is normal behavior with IS-IS, basically it treats
each
level-1 router as a stub area. It will send a default route to a
level-1 area. IF you have a level-1-2 domain you can configure route
leaking
so that the individual routes will show up with the default. For more
information on that see the following link:
http://www.cisco.com/en/US/tech/tk365/tk381/technologies_tech_note09186a
0080093f39.shtml
:)
Sincerely,
John Matijevic, CCIE #13254, MCSE, CNE, CCEA Network Consultant Hablo
Espanol
305-321-6232
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
k_kaloianov@eircom.net
Sent: Sunday, August 08, 2004 7:06 AM
To: ccielab@groupstudy.com
Subject: isis and ATT bit=1
Hi Group,
just a dumb question about isis and IOS ver 12.2, I'm just having two
areas
and one router in one area and two in the other one, the two routers are
L1
and L1/L2 and the other one is L2 or L2/L1, I just want to know whether
we
have to use clns router isis command on L2/L1 iterface connecting /w L1
router or alternatively default-information originate and default static
route to null interface in order to propagate default route to L1
router?
The behaviour that I saw was that even without any of the above
configuration there was a default route created in L1 routing table?
Thanks
in advance:)
Reg,
Kaloyan-:)
This archive was generated by hypermail 2.1.4 : Fri Sep 03 2004 - 07:02:35 GMT-3