From: Prasad Shemrudkar (pshemrud) (pshemrud@cisco.com)
Date: Mon Aug 27 2007 - 15:38:54 ART
Hi Guys,
I needed a little clarification on the ospf database. Scenario and my
question as follows:
R4-------R3--------R1
| |
| |
SW1 -------------------SW2
SW2 and R3 are ASBR's and redistributing eigrp into ospf. Loopback of R3
is 150.1.3.3 is advertised in EIGRP.
And in R4's routing table 150.1.3.3 is received from SW2, even though R3
is directly connected to it.
Routers running ospf only: SW1,R4
Routers running eigrp only : R1
ASBRs: R3 and SW2
Rack1R4(config-if)#do sh ip route 150.1.3.3
Routing entry for 150.1.3.0/24
Known via "ospf 1", distance 110, metric 20
Tag 90, type extern 2, forward metric 30
Last update from 164.1.47.7 on Ethernet0/0, 00:11:41 ago
Routing Descriptor Blocks:
* 164.1.47.7, from 150.1.8.8, 00:11:41 ago, via Ethernet0/0
Route metric is 20, traffic share count is 1
Route tag 90
The ospf database shows that it has been indeed learnt from both SW2
(150.1.8.8) and R3 (150.1.3.3) albeit installs only the one learnt from
SW2. I could not find much difference between the 2 LSAs except "Routing
Bit Set on this LSA".
Rack1R4#sh ip ospf data external 150.1.3.0
OSPF Router with ID (150.1.4.4) (Process ID 1)
Type-5 AS External Link States
LS age: 1473
Options: (No TOS-capability, DC)
LS Type: AS External Link
Link State ID: 150.1.3.0 (External Network Number )
Advertising Router: 150.1.3.3
LS Seq Number: 80000001
Checksum: 0xF419
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: 90
Routing Bit Set on this LSA
LS age: 1320
Options: (No TOS-capability, DC)
LS Type: AS External Link
Link State ID: 150.1.3.0 (External Network Number )
Advertising Router: 150.1.8.8
LS Seq Number: 80000001
Checksum: 0xB350
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: 90
Is this expected or am I missing something here? The metric for both,
being ospf external is 20, so that's ruled out.
TIA,
Prasad
This archive was generated by hypermail 2.1.4 : Sat Sep 01 2007 - 11:32:13 ART