RE: OSPF NSSA forwarding address suppression

From: Victor Cappuccio (vcappuccio@desca.com)
Date: Sat Dec 30 2006 - 23:53:08 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

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#

Thanks
Victor.-

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Nick Griffin
Sent: Saturday, December 30, 2006 10:20 PM
To: Thiago Vazquez
Cc: ccie anees; ccielab@groupstudy.com
Subject: Re: OSPF NSSA forwarding address suppression

This may help:

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009
405a.shtml

On 12/30/06, Thiago Vazquez <thiago.vazquez@uk.easynet.net> wrote:
>
> Mate,
>
> If you got Doyle's book (vol 1), take a look on Case Study: Address
> Summarization - pag 435. It will give u great details about it.
>
> Cheers, Thiago
>
> ----------------------------------------------------------------------
> Network Operations Center
> Easynet
> email: thiago.vazquez@uk.easynet.net
> team email: networks.support@uk.easynet.net
> tel.: +44 (0) 207 032 8006
> ----------------------------------------------------------------------
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> ccie anees
> Sent: 31 December 2006 01:12
> To: ccielab@groupstudy.com
> Subject: OSPF NSSA forwarding address suppression
>
>
> Hi,
>
> how this command works?
>
> area 2 nssa translate type7 suppress-fa
>
> Thanks,
>
> Anees.
>
> __________________________________________________
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>



This archive was generated by hypermail 2.1.4 : Tue Jan 02 2007 - 07:50:40 ART