RE: forwarding address question

Hi Mustafa,
Forwarding address means that to reach x network specified in the LSA,
you need to send packets to FA. So in your case to reach 150.9.8.0
(check LSA) you need to go to forwarding address (141.9.255.8).
From your route table 141.9.255.8 is reachable via 141.9.0.8.

141.9.255.0/24 [110/2] via 141.9.0.8, 01:03:27, FastEthernet0/1

Above is the reason because of which actual next hop after recursion is
141.9.0.8

*O N2 150.9.8.0/24 [110/20] via 141.9.0.8, 01:03:27, FastEthernet0/1*

Please have a look at below link to know more information.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009
405a.shtml#topic1

Thanks,
Sonu

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
Mustafa Yadav
Sent: Saturday, September 18, 2010 2:47 PM
To: Cisco certification
Subject: forwarding address question

hi,

as you see below in ospf database for one prefix the forwording address
is
141.9.255.8 but in the routing table the next hop is different.Can
someone
explain what is the meaning of forwarding address if it is not a next
hop in
this case?

 LS age: 1790
  Options: (No TOS-capability, DC)
  LS Type: AS External Link
  Link State ID: 150.9.8.0 (External Network Number )
  Advertising Router: 150.9.5.5
  LS Seq Number: 80000004
  Checksum: 0x9419
  Length: 36
  Network Mask: /24
        Metric Type: 2 (Larger than any link state path)
        TOS: 0
        Metric: 20
        *Forward Address: 141.9.255.8*
        External Route Tag: 0

Rack9R5#$ sh ip route
ospf
     51.0.0.0/32 is subnetted, 1 subnets
O E2 51.51.51.51 [110/20] via 193.25.25.2, 01:03:27, Tunnel52
O IA 192.10.9.0/24 [110/1065] via 193.25.25.2, 01:03:27, Tunnel52
     141.9.0.0/16 is variably subnetted, 14 subnets, 2 masks
O 141.9.255.0/24 [110/2] via 141.9.0.8, 01:03:27, FastEthernet0/1
O E1 141.9.6.0/24 [110/1084] via 193.25.25.2, 00:01:33, Tunnel52
O E1 141.9.7.0/24 [110/1084] via 193.25.25.2, 00:01:33, Tunnel52
O 141.9.8.0/24 [110/2] via 141.9.0.8, 01:03:27, FastEthernet0/1
O E1 141.9.36.0/24 [110/1084] via 193.25.25.2, 00:01:33, Tunnel52
O E1 141.9.37.0/24 [110/1084] via 193.25.25.2, 00:01:33, Tunnel52
O E1 141.9.77.0/24 [110/1084] via 193.25.25.2, 00:01:33, Tunnel52
O 141.9.88.0/24 [110/2] via 141.9.0.8, 01:03:27, FastEthernet0/1
O 141.9.123.0/24 [110/1064] via 193.25.25.2, 01:03:27, Tunnel52
     150.9.0.0/16 is variably subnetted, 8 subnets, 2 masks
*O N2 150.9.8.0/24 [110/20] via 141.9.0.8, 01:03:27, FastEthernet0/1*

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Received on Sat Sep 18 2010 - 17:36:43 ART