From: Bob Sinclair (bsin@cox.net)
Date: Sun Jul 25 2004 - 14:51:44 GMT-3
Alsontra,
When you configure two ISIS processes on one router the first one configured
becomes an L2 area and routes from the other areas are automatically
redistributed. The L1 area gets the attached bit set and so has a gateway
of last resort. Details are below from my home lab. R3 and R5 are
connected by Ethernet network 172.16.35.0. R5 and R6 are connected by
Serial on network 172.16.62.0. I configured ISIS area 35 on the Ethernet
link and area 56 on the Serial. Config, output and comments below:
R3#
router isis 35
net 35.3333.3333.3333.00
!
interface Ethernet0
ip address 172.16.35.3 255.255.255.0
ip router isis 35
R5#
router isis 35
net 35.5555.5555.5555.00
!
router isis 56
net 56.5555.5555.5555.00
is-type level-1 !NOTE: this command was inserted automatically. I
configured Area 35 first.
interface Ethernet0
ip address 172.16.35.5 255.255.255.0
ip router isis 35
!
interface Serial1
ip address 172.16.62.1 255.255.255.0
ip router isis 56
clockrate 64000
R6#
router isis 56
net 56.6666.6666.6666.00
interface Serial0
ip address 172.16.62.2 255.255.255.0
ip router isis 56
R3#sh clns is-neighbors
System Id Interface State Type Priority Circuit Id Format
R5-2511 Et0 Up L1L2 64/64 R5-2511.01 Phase V
!NOTE: R3 has a L1/L2 adjacency and it has learned about the Serial link in
Area 56, on the far side of R5.
R3#sh ip route isis
172.16.0.0/24 is subnetted, 4 subnets
i L2 172.16.62.0 [115/20] via 172.16.35.5, Ethernet0
R3#
R6#sh clns is-n
System Id Interface State Type Priority Circuit Id Format
R5-2511 Se0 Up L1 0 00 Phase V
R6#sh ip route
Gateway of last resort is 172.16.62.1 to network 0.0.0.0
!NOTE: R6 has an L1 adjacency with R5, and it has a default via the ATT bit
from R5
172.16.0.0/24 is subnetted, 6 subnets
C 172.16.62.0 is directly connected, Serial0
C 172.16.14.0 is directly connected, Ethernet0
C 172.16.106.0 is directly connected, Loopback6
C 172.16.69.0 is directly connected, Loopback3
C 172.16.64.0 is directly connected, Loopback0
C 172.16.65.0 is directly connected, Loopback1
i*L1 0.0.0.0/0 [115/10] via 172.16.62.1, Serial0
R5-2511#sh clns is-n
Area 35:
System Id Interface State Type Priority Circuit Id Format
R3 Et0 Up L1L2 64/64 R5-2511.01 Phase V
Area 56:
System Id Interface State Type Priority Circuit Id Format
R6 Se1 Up L1 0 00 Phase V
Bob Sinclair
CCIE #10427, CISSP, MCSE
www.netmasterclass.net
----- Original Message -----
From: <alsontra@hotmail.com>
To: "Bob Sinclair" <bsin@cox.net>
Cc: <ccielab@groupstudy.com>
Sent: Sunday, July 25, 2004 2:40 PM
Subject: Redistributing all Level 1 IP routes into the Level 2 process - by
default
> Hi Bob,
>
> Will a router with two separate ISIS processes automatically redistribute
L1
> routes?
>
> I have always used the multiple net statements to support separate ISIS
> areas, so I'm unclear about this point. The document you posted seems to
> suggest that L1 routers on a single router belonging to two separate ISIS
> process will automatically redistribute. Is this correct?
>
> Quote -
>
> "Redistribution- IP routes learned via Level 1 routing are advertised by
> default into Level 2. Even when multiple Level 1 processes are configured
on
> the same unit, this fact is still true. No additional configuration is
> required to redistribute all Level 1 IP routes into the Level 2 process. "
>
>
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t5/ismarea.htm
>
> Thanks,
> Alsontra
>
>
>
>
> Dehong,
> If you are required to have differet interfaces on the same router in
> different ISIS areas, then I would suggest two different ISIS processes.
> This is the approach suggested by Cisco in the link below. When you
> configure multiple NETs under one process, your database will show a
single,
> merged area.
>
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t5/ismarea.htm
> Bob Sinclair
> CCIE #10427, CISSP, MCSE
> www.netmasterclass.net
> ----- Original Message -----
> From: "Wang Dehong-DWANG1" <Dehong.Wang@motorola.com>
> To: <ccielab@groupstudy.com>
> Sent: Friday, July 23, 2004 4:37 PM
> Subject: ISIS mutiple area question..
>
> > I have another question for the group. If you are asked to configure
> multiple areas, say 2, under one router, should you configure two net
> statements under one router isis or two seperate net statements under
> different router isis? or it doesn't matter? My thought is two router isis
> statements, but I did see case 1 as well, so I would like to clarify it
with
> the group..
> >
> > Case 1:
> >
> > router isis
> > net 49.area-A.xxxx.xxxx.xxxx.00
> > net 49.area-B.xxxx.xxxx.xxxx.00
> >
> > Case 2:
> > router isis
> > net 49.area-A.xxxx.xxxx.xxxx.00
> >
> > router isis area-b
> > net 49.area-B.xxxx.xxxx.xxxx.00
> >
> > thanks in advance..
> >
> > - Dehong
> >
> > _______________________________________________________________________
> > Please help support GroupStudy by purchasing your study materials from:
> > http://shop.groupstudy.com
> >
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
> _______________________________________________________________________
> Please help support GroupStudy by purchasing your study materials from:
> http://shop.groupstudy.com
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
> ---
> Incoming mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.701 / Virus Database: 458 - Release Date: 6/7/2004
>
> _______________________________________________________________________
> Please help support GroupStudy by purchasing your study materials from:
> http://shop.groupstudy.com
>
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Sun Aug 01 2004 - 10:12:02 GMT-3