04-04-2003 07:23 PM - edited 03-02-2019 06:25 AM
In the following OSPF network topology, is it correct that RTA installs multiple inter-area routes over two links(atm3072, atm3073) with costs, 10 and 1 respectively? If so, does it comply with the OSFP standard, RFC2328?
Any response will be greatly appreciated.
Yongjun.
(10.0.0.0/24)
<---atm3072--->
(cost: 10)
RTA RTB <----------------> RTC
<---atm3073--->(ABR) (20.0.0.0/24)
(74.0.0.0/24)
(cost: 1)
172.31.0.4 172.31.0.1 172.31.0.2
<------------ Area 0 --------> <------- Area 100 ---------->
============ OSPF network routing table ============
N 10.0.0.0/24 [1] area: 0.0.0.0
N IA 20.0.0.0/24 [2] area: 0.0.0.0 /* ?? */
via 10.0.0.1, atm3072
via 74.0.0.1, atm3073
N IA 38.0.0.0/24 [3] area: 0.0.0.0 /* ?? */
via 10.0.0.1, atm3072
via 74.0.0.1, atm3073
N 74.0.0.0/24 [2] area: 0.0.0.0
via 10.0.0.1, atm3072
via 74.0.0.1, atm3073
N 172.31.0.1/32 [2] area: 0.0.0.0
via 10.0.0.1, atm3072
via 74.0.0.1, atm3073
N IA 172.31.0.2/32 [3] area: 0.0.0.0 /* ?? */
via 10.0.0.1, atm3072
via 74.0.0.1, atm3073
N 172.31.0.4/32 [1] area: 0.0.0.0
directly attached to loopback0
-----------------------------------------------------------------
04-06-2003 04:48 PM
I am not able to understand the network topology.
04-06-2003 05:23 PM
Sorry for the corrupted topology.
In the routing table of RTA below, RTA keeps two routing entries over two links, atm3072 and atm3073 with unequal costs, 10 and 1 respectively,
for inter-area destinations and ABR itself. What I'm asking about is whether if RTA complies with the OSPF standard, RFC2328. Otherwise, does RTA work incorrectly?
(10.0.0.0/24)
<---atm3072--->
RTA RTB <----------------> RTC
<---atm3073---> (ABR) (20.0.0.0/24)
(74.0.0.0/24)
<--------- Area 0 --------> <------- Area 100 ---------->
RTA lo: 172.31.0.4, RTB lo: 172.31.0.1, RTC lo: 172.31.0.2
============ OSPF network routing table in RTA ============
N 10.0.0.0/24 [1] area: 0.0.0.0
N IA 20.0.0.0/24 [2] area: 0.0.0.0 /* ?? */
via 10.0.0.1, atm3072
via 74.0.0.1, atm3073
N IA 38.0.0.0/24 [3] area: 0.0.0.0 /* ?? */
via 10.0.0.1, atm3072
via 74.0.0.1, atm3073
N 74.0.0.0/24 [2] area: 0.0.0.0
via 10.0.0.1, atm3072
via 74.0.0.1, atm3073
N 172.31.0.1/32 [2] area: 0.0.0.0
via 10.0.0.1, atm3072
via 74.0.0.1, atm3073
N IA 172.31.0.2/32 [3] area: 0.0.0.0 /* ?? */
via 10.0.0.1, atm3072
via 74.0.0.1, atm3073
N 172.31.0.4/32 [1] area: 0.0.0.0
directly attached to loopback0
04-06-2003 11:18 PM
I guess this is your topology. RTA and RTB are connected via two links (atm 3072, atm 3073) and these links fall in area 0. Link between B and C is in area 100.
Have you modified the ospf cost ? where have you applied the ospf cost command ?
04-06-2003 11:55 PM
Your understanding on my topology is exactly right.
We have applied the ospf costs with 1and 10 for atm3072 and atm3073, respectively in RTA.
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