From: Victor Cappuccio (victor@ccbootcamp.com)
Date: Wed May 23 2007 - 13:11:13 ART
If I may add
SW1#show ip ospf database external 2.2.2.0
OSPF Router with ID (9.9.9.9) (Process ID 1)
Type-5 AS External Link States
Routing Bit Set on this LSA
LS age: 58
Options: (No TOS-capability, DC)
LS Type: AS External Link
Link State ID: 2.2.2.0 (External Network Number )
Advertising Router: 4.4.4.4
LS Seq Number: 80000001
Checksum: 0xAC5A
Length: 36
Network Mask: /24
Metric Type: 2 (Larger than any link state path)
TOS: 0
Metric: 20
Forward Address: 192.168.24.2
External Route Tag: 0
Now If you do not know about 192.168.24.2, This shows us the forwarding
address for this external route
SW1#show ip route 192.168.24.2
% Network not in table
SW1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address
Interface
4.4.4.4 1 FULL/BDR 00:00:32 192.168.14.4 Vlan14
1.1.1.1 255 FULL/DR 00:00:37 192.168.100.1
Vlan100
10.10.10.10 1 FULL/BDR 00:00:36 192.168.100.10
Vlan100
SW1#show ip ospf database
OSPF Router with ID (150.150.0.1) (Process ID 100)
OSPF Router with ID (9.9.9.9) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link
count
1.1.1.1 1.1.1.1 86 0x80000142 0x00BB4E 4
4.4.4.4 4.4.4.4 20 0x80000005 0x00EA1B 1
6.6.6.6 6.6.6.6 897 0x8000012B 0x005A47 3
9.9.9.9 9.9.9.9 25 0x80000143 0x006822 4
10.10.10.10 10.10.10.10 87 0x8000002B 0x00766C 2
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
192.168.14.10 9.9.9.9 26 0x80000001 0x00DB84
192.168.100.1 1.1.1.1 70 0x80000002 0x00F71A
Type-5 AS External Link States
Link ID ADV Router Age Seq# Checksum Tag
2.2.2.0 4.4.4.4 16 0x80000001 0x00AC5A 0
Looking at the OSPF External database
SW1#show ip ospf database external 2.2.2.0
OSPF Router with ID (150.150.0.1) (Process ID 100)
OSPF Router with ID (9.9.9.9) (Process ID 1)
Type-5 AS External Link States
LS age: 23
Options: (No TOS-capability, DC)
LS Type: AS External Link
Link State ID: 2.2.2.0 (External Network Number )
Advertising Router: 4.4.4.4
LS Seq Number: 80000001
Checksum: 0xAC5A
Length: 36
Network Mask: /24
Metric Type: 2 (Larger than any link state path)
TOS: 0
Metric: 20
Forward Address: 192.168.24.2
External Route Tag: 0
SW1#show ip route 192.168.24.0
% Network not in table
SW1#ping 2.2.2.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
SW1#
RTR-TS1#4
[Resuming connection 4 to R4 ... ]
*Mar 2 01:09:09.225: %OSPF-5-ADJCHG: Process 100, Nbr 2.2.2.2 on
Serial0.42 from LOADING to FULL, Lo
R4(config-router)#router ospf 100
R4(config-router)#
R4(config-router)#area 42 nssa translate type7 suppress-fa
R4(config-router)#
RTR-TS1#2
[Resuming connection 2 to sw1 ... ]
SW1#show ip ospf database external 2.2.2.0
OSPF Router with ID (150.150.0.1) (Process ID 100)
OSPF Router with ID (9.9.9.9) (Process ID 1)
Type-5 AS External Link States
Routing Bit Set on this LSA
LS age: 8
Options: (No TOS-capability, DC)
LS Type: AS External Link
Link State ID: 2.2.2.0 (External Network Number )
Advertising Router: 4.4.4.4
LS Seq Number: 80000002
Checksum: 0x2564
Length: 36
Network Mask: /24
Metric Type: 2 (Larger than any link state path)
TOS: 0
Metric: 20
Forward Address: 0.0.0.0 ---------- Forwarding address modified
External Route Tag: 0
SW1#ping 2.2.2.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 59/62/67 ms
SW1#
SW1#show ip route 2.2.2.2
Routing entry for 2.2.2.0/24
Known via "ospf 1", distance 110, metric 20, type extern 2, forward
metric 1
Last update from 192.168.14.4 on Vlan14, 00:02:09 ago
Routing Descriptor Blocks:
* 192.168.14.4, from 4.4.4.4, 00:02:09 ago, via Vlan14
Route metric is 20, traffic share count is 1
SW1#show ip route 0.0.0.0
% Network not in table
SW1#
Another example of this could be
http://www.groupstudy.com/archives/ccielab/200508/msg01333.html
thanks,
Victor Cappuccio.-
- CCSI# 31452
Network Learning Inc - A Cisco Sponsored Organization (SO) YES! We take
Cisco Learning credits!
victor@ccbootcamp.com
http://www.ccbootcamp.com (Cisco Training and Rental Racks)
http://www.ccbootcamp.com/groupstudy.html (groupstudy member discounts!)
Voice: 702-968-5100
FAX: 702-446-8012
-----Original Message-----
From: nobody@groupstudy.com on behalf of Bit Gossip
Sent: Wed 5/23/2007 8:54
To: Ivan; ccielab@groupstudy.com
Subject: Re: NSSA FA Supression
Hi Ivan, group,
I have labbed initial Cagri setup with R2 and R3 ABRs between nssa area and
area 0. Indeed only one ABR, in my case R2, translates the N2 into E2. I
still don't get that! Why R3 doesn't translate?
Thanks,
Bit.
R2#show ip route ospf
1.0.0.0/24 is subnetted, 5 subnets
O 1.1.13.0 [110/845] via 1.1.12.1, 00:05:34, Serial4/0.12
O 1.1.34.0 [110/128] via 1.1.24.4, 19:42:27, Serial4/0.24
4.0.0.0/24 is subnetted, 1 subnets
O N2 4.4.4.0 [110/20] via 1.1.24.4, 00:05:34, Serial4/0.24
R3#show ip route ospf
1.0.0.0/24 is subnetted, 5 subnets
O 1.1.12.0 [110/845] via 1.1.13.1, 00:05:57, Serial4/0.13
O 1.1.24.0 [110/128] via 1.1.34.4, 19:42:50, Serial4/0.34
4.0.0.0/24 is subnetted, 1 subnets
O E2 4.4.4.0 [110/20] via 1.1.34.4, 00:05:57, Serial4/0.34
~~~~~~~~~~~~~~~~~~~~~~R1
interface Serial0/0.12 point-to-point
ip address 1.1.12.1 255.255.255.0
frame-relay interface-dlci 102
!
interface Serial0/0.13 point-to-point
ip address 1.1.13.1 255.255.255.0
frame-relay interface-dlci 103
!
!
router ospf 1
router-id 1.1.1.1
network 1.1.12.1 0.0.0.0 area 0
network 1.1.13.1 0.0.0.0 area 0
~~~~~~~~~~~~~~~~~~~~~~~~R2
interface Serial4/0.12 point-to-point
ip address 1.1.12.2 255.255.255.0
frame-relay interface-dlci 201
!
interface Serial4/0.24 point-to-point
ip address 1.1.24.2 255.255.255.0
frame-relay interface-dlci 204
!
interface Serial4/1
ip address 1.1.23.2 255.255.255.0
serial restart-delay 0
!
router ospf 1
area 1 nssa
network 1.1.12.2 0.0.0.0 area 0
network 1.1.23.2 0.0.0.0 area 0
network 1.1.24.2 0.0.0.0 area 1
~~~~~~~~~~~~~~~~~~~~~~~~R3
interface Serial4/0.13 point-to-point
ip address 1.1.13.3 255.255.255.0
frame-relay interface-dlci 301
!
interface Serial4/0.34 point-to-point
ip address 1.1.34.3 255.255.255.0
frame-relay interface-dlci 304
!
interface Serial4/3
ip address 1.1.23.3 255.255.255.0
serial restart-delay 0
!
router ospf 1
area 1 nssa
network 1.1.13.3 0.0.0.0 area 0
network 1.1.23.1 0.0.0.0 area 0
network 1.1.34.3 0.0.0.0 area 1
!
~~~~~~~~~~~~~~~~~~~~~~~~R4
interface Loopback0
ip address 4.4.4.4 255.255.255.0
!
interface Serial0/0.24 point-to-point
ip address 1.1.24.4 255.255.255.0
frame-relay interface-dlci 402
!
interface Serial0/0.34 point-to-point
ip address 1.1.34.4 255.255.255.0
frame-relay interface-dlci 403
!
router ospf 1
area 1 nssa
redistribute connected subnets
network 1.1.24.4 0.0.0.0 area 1
network 1.1.34.4 0.0.0.0 area 1
!
----- Original Message -----
From: "Ivan" <ivan@iip.net>
To: <ccielab@groupstudy.com>; "Cagri Yucel" <cyucel@gmail.com>
Sent: Monday, May 14, 2007 9:09 AM
Subject: Re: NSSA FA Supression
> suppress fa is used to manage Forward Addres in the OSPF LSA. This feature
> can't converse type of route.
>
>
>
>
>
>
>
> Please take some time and look at this config
>
>
> area 1 (NSSA) Area 0
> R1 --------------------- R2 ------------------- R3
> X.X.12.0/30 X.X.23.0/30
>
> Step1:
> ######
> R1:
> redistribute Loopback0 (1.1.1.1)
>
> Verify Result
> ##############
> in R3:
> show ip route will show
> 1.1.1.0/24 as E2 route.
> X.X.12.0/30 as O IA route
> ************************************************************
> Step2:
> ######
> Suppress Area 1 route X.X.12.0/24 in Area 0
> ###########################################
> R2:
> router ospf 1
> area 1 range X.X.12.0 255.255.255.0 no-advertise
>
> Verify in R3:
> show ip route
> you will not see both the routes X.X.12.0/30 and 1.1.1.0/24
>
> R3#show ip ospf database external
> OSPF Router with ID (3.3.3.3) (Process ID 1)
> Type-5 AS External Link States
> Routing Bit Set on this LSA
> LS age: 168
> Options: (No TOS-capability, DC)
> LS Type: AS External Link
> Link State ID: 1.1.1.0 (External Network Number )
> Advertising Router: 1.1.1.1
> LS Seq Number: 80000001
> Checksum: 0x38F0
> Length: 36
> Network Mask: /24
> Metric Type: 2 (Larger than any link state path)
> TOS: 0
> Metric: 20
> Forward Address: 1.1.12.1 <-----------------------------
> External Route Tag: 0
> Note:
> you can see above that the forwarding address 1.1.12.1 for the
> redistributed
> route 1.1.1.0.
> And we filtered the X.X.12.0 from ABR (R2).
> Because R3 does not have route to reach X.X.12.1, it can not populate
> 1.1.1.1
> in R3 Routing table.
>
>
*****************************************************************************
*****
> Step3:
> ######
> NSSA forwarding address suppression
> ###################################
> R2:
> router ospf 1
> area 1 nssa translate type7 suppress-fa
> Verify in R3
>
> R3#show ip ospf database external
> OSPF Router with ID (3.3.3.3) (Process ID 1)
> Type-5 AS External Link States
> Routing Bit Set on this LSA
> LS age: 6
> Options: (No TOS-capability, DC)
> LS Type: AS External Link
> Link State ID: 1.1.1.0 (External Network Number )
> Advertising Router: 1.1.1.1
> LS Seq Number: 80000002
> Checksum: 0x61D6
> Length: 36
> Network Mask: /24
> Metric Type: 2 (Larger than any link state path)
> TOS: 0
> Metric: 20
> Forward Address: 0.0.0.0 <-----------------------------
> External Route Tag: 0
>
> Note: Now the forwarding address is 0.0.0.0 which is nothing but the
> border-router. Now the router knows how to reach the border-router
> which is X.X.23.2, it populates 1.1.1.0/24 in the routing table.
>
> R3#show ip ospf border-routers
> OSPF Process 1 internal Routing Table
> Codes: i - Intra-area route, I - Inter-area route
>
> i 2.2.2.2 [647] via 1.1.23.2, Serial1/2, ABR/ASBR, Area 3, SPF 117
>
>
>
>
>
>
>
>
>
>
> On Sunday 13 May 2007 17:32, Cagri Yucel wrote:
>> I managed to solve this question but no idea how it works, I'll be glad
>> if
>> someone enlighten me on this issue
>>
>> R2
>>
>> R1 0 10 R4
>>
>> R3
>>
>> Sorry for dodgy diagram, R1 connected to R2 and R3. R4 connected to R2
>> and
>> R3 and there is a link between R2 and R3.
>> Area 10 is NSSA
>> R4 redistribute one of its loopback
>>
>> Now, this route seems as N2 on R3 and E2 on R2 (depending who is doing
>> the
>> 7to5 conversion)
>>
>> Question asking to have it as N2 on both.
>>
>> When I put area 30 nssa translate type-7 suppress-fa
>> on the router doing conversion I managed to achieve N2 on both routers.
>>
>> What is the idea behind ?
>>
>> Many thanks
>
> _______________________________________________________________________
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This archive was generated by hypermail 2.1.4 : Fri Jun 01 2007 - 06:55:21 ART