From: Victor Cappuccio (vcappuccio@gmail.com)
Date: Mon Oct 13 2008 - 08:38:39 ART
Hi these are my notes about this great protocol. As far as I know you must
enable the Protocol "CLNS in these case" in order to have that protocol
running as well..
OSI CLNS is a network layer service similar to bare IP service.
There are some rules that apply to these network layer addresses
Each IS-IS router must also have a way to uniquely identify itself within
the routing domain.
R1(config-router)#net 49.0001.0000.0000.1111.00 %CLNS: System ID (0100.0101.
0101.0101) must not change when defining additional area addresses
R1(config-router)#net 49.0001.0000.0000.1111.00
%CLNS: System ID (0100.0101.0101.0101) must not change when defining
additional area addresses
This identification is the function of the System ID, which is analogous to
the OSPF Router ID
A router can have up to *three area addresses*
2nd Area Address
R1(config-router)#net 49.0100.0101.0101.0101.00
R1(config-router)#net 49.0100.0101.0101.0101.00
3er Area address
R1(config-router)#net 50.0100.0101.0101.0101.00
R1(config-router)#net 50.0100.0101.0101.0101.00
And is could happen if you have more than 3
R1(config-router)#net 51.0100.0101.0101.0101.00
%The maximum allowed addresses already configured
R1(config-router)#do show run | b ^router isis
router isis
net 47.0011.0000.0001.0100.0100.0101.0101.0101.00
net 49.0001.0102.0304.0506.00
net net 49.0100.0101.0101.0101.00
!
R1(config-router)#net 51.0100.0101.0101.0101.00
%The maximum allowed addresses already configured
R1(config-router)#do show run | b ^router isis
router isis
net 47.0011.0000.0001.0100.0100.0101.0101.0101.00
net 49.0001.0102.0304.0506.00
net net 49.0100.0101.0101.0101.00
!
*the Network Entity Titles* here is defined by rfc163, the use of a .00 of
NSel within the NSAP identifies the network layer itself. OSI network layer
addressing is implemented with *NSAP addresses*
R3(config-router)#net ?
XX.XXXX. ... .XXX.XX Network entity title (NET)
*There are 3 NSAP formats:
*
*A simple eight-octet Area ID/System ID format: *AREA|SysID|SEL
Area: The Area field is used to route between areas using Level 2 routing.
System ID: The ID field is used to route to a host or router within the area
using Level 1 routing.
SEL: The SEL field is used to route to an entity with the host or ES.
*A OSI NSAP format: *|Area|Area|Area|ID|SEL
and *the GOSIP NSAP format*
The *NET *(Network Entity Title) address is the address of the host, where
the value in the SEL field is set to 0W00. Refers to the device itself
(equivalent to the Layer 3 OSI address of the device)
The *NSAP (Network Service Access Point)* The SEL field at the end of the
ISO address specifies the upper-layer protocol. Similar to the Protocol
field of the IP header.
an example here R1 and R2 connected over the serial 1/0 exchanging CLNS
information:
R1(config-if)#do show run | b ^router isis
router isis
net 49.0001.1111.1111.1111.00router isis
net 49.0001.1111.1111.1111.00
R1(config-if)#do show run int s1/0
Building configuration...
Current configuration : 85 bytes
!
interface Serial1/0
no ip address
serial restart-delay 0
clns router isis
end
R1(config-if)#do show clns neigh
System Id Interface SNPA State Holdtime Type
Protocol
R2 Se1/0 *HDLC* Up 26 L2 IS-IS
R1(config-if)#
we can see that R1 here is learning
R1(config-if)#do show clns neigh
System Id Interface SNPA State Holdtime Type
Protocol
R2 Se1/0 *HDLC* Up 26 L2 IS-IS
R1(config-if)#do show clns route
Codes: C - connected, S - static, d - DecnetIV
I - ISO-IGRP, i - IS-IS, e - ES-IS
B - BGP, b - eBGP-neighbor
C 49.0001.1111.1111.1111.00 [1/0], Local IS-IS NET
C 49.0001 [2/0], Local IS-IS Area
i 49.0002 [110/10]
via R2, Serial1/0
I added the following to r2
R2(config-if)#router isis
R2(config-router)#router isis
R2(config-router)# net 49.0002.2222.2222.2222.00
R2(config-router)# net 49.0004.2222.2222.2222.00 ! New entry
and R1 has now
R1(config-if)#do show clns ro
Codes: C - connected, S - static, d - DecnetIV
I - ISO-IGRP, i - IS-IS, e - ES-IS
B - BGP, b - eBGP-neighbor
C 49.0001.1111.1111.1111.00 [1/0], Local IS-IS NET
C 49.0001 [2/0], Local IS-IS Area
i 49.0004 [110/10]
via R2, Serial1/0
i 49.0002 [110/10]
via R2, Serial1/0
had nothing to do with redistribute connected
but now if I configure IP addresses between the serial and redistribute the
connected not announced to ISIS, the protocol redistributes this information
and this is propagated using CLNS information
R2(config-router)#int s1/0
R2(config-if)#ip add 10.1.12.2 255.255.255.0
R2(config-if)#ip router isis
R2(config-if)#int lo232
R2(config-if)#ip add 200.2
*Oct 13 13:32:58.991: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Loopback23
2, changed state to up
R2(config-if)#ip add 200.200.200.200 255.255.255.255
R2(config-if)#router isis
R2(config-router)#red con
R2(config-router)#
R1(config-if)#ip add 10.1.12.1 255.255.255.0
R1(config-if)#ip router isis
R1(config-if)#do show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static
route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
200.200.200.0/32 is subnetted, 1 subnets
i L2 200.200.200.200 [115/10] via 10.1.12.2, Serial1/0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.12.0 is directly connected, Serial1/0
12.0.0.0/32 is subnetted, 1 subnets
C 12.12.12.12 is directly connected, Loopback100
150.2.0.0/32 is subnetted, 1 subnets
C 150.2.2.2 is directly connected, Loopback0
R1(config-if)#do show clns route
Codes: C - connected, S - static, d - DecnetIV
I - ISO-IGRP, i - IS-IS, e - ES-IS
B - BGP, b - eBGP-neighbor
C 49.0001.1111.1111.1111.00 [1/0], Local IS-IS NET
C 49.0001 [2/0], Local IS-IS Area
i 49.0004 [110/10]
via R2, Serial1/0
i 49.0002 [110/10]
via R2, Serial1/0
R1(config-if)#
so I can assume based on these interesting lab that when you configure red
con under the router isis, u are using the TLV values 128, 130 and 132
http://www.iana.org/assignments/isis-tlv-codepoints
I hope this helps
Victor-.
On Sun, Oct 12, 2008 at 11:21 PM, Yusuf, Daniel (NSN - MA/Rabat) <
daniel.yusuf@nsn.com> wrote:
> Dear GS
>
> If I make redistribution of connected route in ISIS, then does ISIS also
> redistribute CNLS protocol automatically?
>
> Or, it redistributes ip only ?
>
>
> Thanks for the answer
>
> -daniel
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
>
>
>
>
>
>
-- Victor Cappuccio CCIE R/S# 20657 CCSI# 30452 www.anetworkerblog.comBlogs and organic groups at http://www.ccie.net
This archive was generated by hypermail 2.1.4 : Sat Nov 01 2008 - 15:35:20 ARST