Alternate solution to Task 4.9

The configuration I used for this task was:

R3

router ospf 1
area 23 nssa
area 23 nssa default-information-originate no-summary
!
R2

router ospf 1
area 23 nssa
area 23 nssa default-information-originate
!
SW2

router ospf 1
area 23 nssa

This works because R2 will advertise the default as an “N2” external route were as R3 will advertise the default as an “O*IA” route. The preferred OSPF routes are “intra-area” over “inter-area” over E1/N1 over E2/N2”

SW2 will use R2 for any "inter-area" routes as an NSSA ABR will suppress only Type 5 LSA's whereas R3 will suppress Type 3/4/5 LSA's as it is configured to ba a "Not So Totally Stub Area" ABR. This will meet the requirements as the task didn't mention that R3 was only to be used for inter-area routes as well.

Rack1SW2#show ip route | in 0.0.0.0
Gateway of last resort is 173.1.23.3 to network 0.0.0.0
O*IA 0.0.0.0/0 [110/2] via 173.1.23.3, 1d11h, Vlan23

Link ID ADV Router Age Seq# Checksum
0.0.0.0 150.1.3.3 1599 0x8000003F 0x004218
150.1.1.1 150.1.2.2 275 0x80000003 0x000678
150.1.2.2 150.1.2.2 524 0x80000042 0x006D50
150.1.3.3 150.1.2.2 275 0x80000003 0x005961
150.1.5.5 150.1.2.2 524 0x80000042 0x00B0C6
173.1.13.0 150.1.2.2 275 0x80000003 0x005508
173.1.32.0 150.1.2.2 275 0x80000003 0x000189
173.1.125.0 150.1.2.2 276 0x80000045 0x007971
173.1.137.1 150.1.2.2 1036 0x80000005 0x00CF44
173.1.137.3 150.1.2.2 276 0x80000003 0x005BC2
173.1.137.7 150.1.2.2 1036 0x80000006 0x00917B

Type-7 AS External Link States (Area 23)

Link ID ADV Router Age Seq# Checksum Tag
0.0.0.0 150.1.2.2 525 0x80000040 0x0021B5 0
80

Comments

Sign In or Register to comment.