NETWORK NOTES : 2015

Sunday, October 25, 2015

High Availability Protcol - HSRP , VRRP and GLBP

R1
interface FastEthernet0/0
ip address 10.0.0.254 255.255.255.0
standby 1 ip 10.0.0.1
end

interface FastEthernet0/0

ip address 10.0.0.253 255.255.255.0

standby 1 ip 10.0.0.1

interface FastEthernet0/0

ip address 10.0.0.252 255.255.255.0

standby 1 ip 10.0.0.1

end

********************************LOGS********************

R1#sh standby

FastEthernet0/0 - Group 1

State is Active

2 state changes, last state change 00:16:20

Virtual IP address is 10.0.0.1

Active virtual MAC address is 0000.0c07.ac01

Local virtual MAC address is 0000.0c07.ac01 (v1 default)

Hello time 3 sec, hold time 10 sec

Next hello sent in 2.904 secs

Preemption disabled

Active router is local

Standby router is 10.0.0.253, priority 100 (expires in 7.884 sec)

Priority 100 (default 100)

Group name is "hsrp-Fa0/0-1" (default)

R1#

FastEthernet0/0 - Group 1

State is Standby

4 state changes, last state change 00:15:00

Virtual IP address is 10.0.0.1

Active virtual MAC address is 0000.0c07.ac01

Local virtual MAC address is 0000.0c07.ac01 (v1 default)

Hello time 3 sec, hold time 10 sec

Next hello sent in 2.492 secs

Preemption disabled

Active router is 10.0.0.254, priority 100 (expires in 8.540 sec)

Standby router is local

Priority 100 (default 100)

Group name is "hsrp-Fa0/0-1" (default)

R2#

R3#sh standby

FastEthernet0/0 - Group 1

State is Listen

3 state changes, last state change 00:17:10

Virtual IP address is 10.0.0.1

Active virtual MAC address is 0000.0c07.ac01

Local virtual MAC address is 0000.0c07.ac01 (v1 default)

Hello time 3 sec, hold time 10 sec

Preemption disabled

Active router is 10.0.0.254, priority 100 (expires in 8.824 sec)

Standby router is 10.0.0.253, priority 100 (expires in 9.792 sec)

Priority 100 (default 100)

Group name is "hsrp-Fa0/0-1" (default)

Case 1 - interface is down

R2(config)#int fa0/0

R2(config-if)#shut

R2#sh standby

FastEthernet0/0 - Group 1

State is Init (interface down)

R3#sh standby

FastEthernet0/0 - Group 1

State is Standby >>>> This is now in standby mode

Case 2 Active router is down

int f0/0

shut

R3#

*Mar 1 00:37:26.051: %HSRP-5-STATECHANGE: FastEthernet0/0 Grp 1 state Standby -> Active

R3#

R3#sh standby

FastEthernet0/0 - Group 1

State is Active

5 state changes, last state change 00:03:03

Virtual IP address is 10.0.0.1

Active virtual MAC address is 0000.0c07.ac01

Local virtual MAC address is 0000.0c07.ac01 (v1 default)

10.0.0.1 icmp_seq=259 ttl=255 time=46.800 ms

10.0.0.1 icmp_seq=260 ttl=255 time=46.800 ms

10.0.0.1 icmp_seq=261 timeout With a packet drop traffic switched over

10.0.0.1 icmp_seq=262 ttl=255 time=62.400 ms

10.0.0.1 icmp_seq=263 ttl=255 time=62.400 ms

*****************

Sh arp

***************

VPCS[1]> arp

00:00:0c:07:ac:01 10.0.0.1 expires in 111 seconds

R3#sh ip arp

Protocol Address Age (min) Hardware Addr Type Interface

Internet 10.0.0.1 - 0000.0c07.ac01 ARPA FastEthernet0/0

Internet 10.0.0.10 4 0050.7966.6800 ARPA FastEthernet0/0

Internet 10.0.0.252 - c202.1850.0000 ARPA FastEthernet0/0

If a router , which was active earlier , is up again, there will be no change in active gateway this router will be in standby mode.

R1(config)#int fa0/0

R1(config-if)#no shut

R1(config-if)#^Z

R1#

*Mar 1 00:44:20.503: %HSRP-5-STATECHANGE: FastEthernet0/0 Grp 1 state Speak -> Standby

R1#

to make this router again an active gateway preempt is used.

R1(config)#int fa0/0

R1(config-if)#standby 1 preempt delay minimum 3

R1(config-if)#standby 1 priority 200

R1#

*Mar 1 00:50:02.187: %SYS-5-CONFIG_I: Configured from console by console

R1#

*Mar 1 00:50:05.251: %HSRP-5-STATECHANGE: FastEthernet0/0 Grp 1 state Standby -> Active

R1#sh

in 3 second this router is again ACTIVE.

Tuesday, September 1, 2015

OSPF- Miscellaneous

1.OSPF Distance Command

9.9.9 .9/32 is advertised by R9

R6

router ospf 10
network 6.6.6.6 0.0.0.0 area 3
network 16.0.0.0 0.0.0.255 area 3
network 69.0.0.0 0.255.255.255 area 3
distance 205 1.1.1.1 0.0.0.0 20

access-list 20 permit 9.9.9.9

***************************LOG***********************

Show ip route

6.0.0.0/32 is subnetted, 1 subnets
C 6.6.6.6 is directly connected, Loopback0
9.0.0.0/32 is subnetted, 1 subnets
O IA 9.9.9.9 [110/1004] via 16.0.0.1, 00:00:05, FastEthernet0/0
13.0.0.0/24 is subnetted, 1 subnets
O IA 13.0.0.0 [110/2] via 16.0.0.1, 00:00:05, FastEthernet0/0

R6#sh ip route 9.9.9.9
Routing entry for 9.9.9.9/32
Known via "ospf 10", distance 205, metric 1004, type inter area
Last update from 16.0.0.1 on FastEthernet0/0, 00:03:26 ago
Routing Descriptor Blocks:
* 16.0.0.1, from 1.1.1.1, 00:03:26 ago, via FastEthernet0/0
Route metric is 1004, traffic share count is 1

R6#sh ip ospf database summary 9.9.9.9

OSPF Router with ID (66.6.6.6) (Process ID 10)

Summary Net Link States (Area 3)

Routing Bit Set on this LSA in topology Base with MTID 0

LS age: 535

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 9.9.9.9 (summary Network Number)

Advertising Router: 1.1.1.1

LS Seq Number: 80000004

Checksum: 0x180B

Length: 28

Network Mask: /32

MTID: 0 Metric: 1003

R6#

**************************

To make any route unreachable
R6

router ospf 10
network 6.6.6.6 0.0.0.0 area 3
network 16.0.0.0 0.0.0.255 area 3
network 69.0.0.0 0.255.255.255 area 3
distance 255 1.1.1.1 0.0.0.0 20

access-list 20 permit 9.9.9.9

R6#sh ip route 9.9.9.9
% Network not in table
R6

NOTE:- " Prefix will remain in database..'"

OSPF Route Filtering

Case 1 Route filtering with Distribute list

R6

int lo5
ip add 69.1.1.1 255.255.255.255
int lo6
ip add 69.2.1.1 255.255.255.255
int lo7
ip add 69.3.1.1 255.255.255.255
int lo8
ip add 69.4.1.1 255.255.255.255

router ospf 10
#net 69.0.0.0 0.255.255.255 area 3

R1

access-list 1 deny 69.1.1.1
access-list 1 deny 69.2.1.1
access-list 1 permit any

router ospf 10

distribute-list 1 in

***************************LOG************************

********************************************************

Before applying the configuration n R1

69.0.0.0/32 is subnetted, 4 subnets

O 69.1.1.1 [110/2] via 16.0.0.6, 00:00:06, FastEthernet0/0

O 69.2.1.1 [110/2] via 16.0.0.6, 00:00:07, FastEthernet0/0

O 69.3.1.1 [110/2] via 16.0.0.6, 00:00:07, FastEthernet0/0

O 69.4.1.1 [110/2] via 16.0.0.6, 00:00:07, FastEthernet0/0

after applying the Configuration

69.0.0.0/32 is subnetted, 2 subnets

O 69.3.1.1 [110/2] via 16.0.0.6, 00:00:06, FastEthernet0/0

O 69.4.1.1 [110/2] via 16.0.0.6, 00:00:06, FastEthernet0/0

69.1.1.1 & 69.2.1.1 is not in Routing table but it will not prevent prefix in Database so other router will have routes in routing table.
filter is only local to the router’s routing table

R2#sh ip ospf database | be Summary Net Link States

Summary Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum

6.6.6.6 1.1.1.1 924 0x80000001 0x006AB4

9.9.9.9 2.2.2.2 1689 0x80000003 0x00E73A

16.0.0.0 1.1.1.1 697 0x80000005 0x009C87

69.1.1.1 1.1.1.1 720 0x80000001 0x00D915

69.2.1.1 1.1.1.1 720 0x80000001 0x00CD20

69.3.1.1 1.1.1.1 720 0x80000001 0x00C12B

69.4.1.1 1.1.1.1 720 0x80000001 0x00B536

172.16.0.2 2.2.2.2 938 0x80000005 0x00ABC6

172.16.0.9 2.2.2.2 938 0x80000005 0x0099E5

69.0.0.0/32 is subnetted, 4 subnets

O IA 69.1.1.1 [110/4] via 23.0.0.3, 00:13:00, FastEthernet0/1

O IA 69.2.1.1 [110/4] via 23.0.0.3, 00:13:00, FastEthernet0/1

O IA 69.3.1.1 [110/4] via 23.0.0.3, 00:13:00, FastEthernet0/1

O IA 69.4.1.1 [110/4] via 23.0.0.3, 00:13:00, FastEthernet0/1

Case -2 OSPF Filtering with Route-Maps

R1(config)#router ospf 10

R1(config-router)#no distribute-list 1 in

route-map filter deny 10

match ip address 1

route-map filter permit 20

access-list 1 permit 69.1.1.1

access-list 1 permit 69.2.1.1

R1(config-router)#distribute-list route-map filter out

% OUT direction is not allowed in case of OSPF

router ospf 10

distribute-list route-map filter in

**************LOGS***************

Summary Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum

6.6.6.6 1.1.1.1 1489 0x80000001 0x006AB4

9.9.9.9 2.2.2.2 238 0x80000004 0x00E53B

16.0.0.0 1.1.1.1 1262 0x80000005 0x009C87

69.1.1.1 1.1.1.1 1285 0x80000001 0x00D915

69.2.1.1 1.1.1.1 1285 0x80000001 0x00CD20

69.3.1.1 1.1.1.1 1285 0x80000001 0x00C12B

69.4.1.1 1.1.1.1 1285 0x80000001 0x00B536

172.16.0.2 2.2.2.2 1506 0x80000005 0x00ABC6

172.16.0.9 2.2.2.2 1506 0x80000005 0x0099E5

R1#sh ip route 69.1.1.1

% Subnet not in table

R1#sh ip route 69.2.1.1

% Subnet not in table

R1#sh ip route 69.3.1.1

Routing entry for 69.3.1.1/32

Known via "ospf 10", distance 110, metric 2, type intra area

Last update from 16.0.0.6 on FastEthernet0/0, 00:00:49 ago

Routing Descriptor Blocks:

* 16.0.0.6, from 66.6.6.6, 00:00:49 ago, via FastEthernet0/0

Route metric is 2, traffic share count is 1

R1#sh ip route 69.4.1.1

Routing entry for 69.4.1.1/32

Known via "ospf 10", distance 110, metric 2, type intra area

Last update from 16.0.0.6 on FastEthernet0/0, 00:00:57 ago

Routing Descriptor Blocks:

* 16.0.0.6, from 66.6.6.6, 00:00:57 ago, via FastEthernet0/0

Route metric is 2, traffic share count is 1

Monday, August 31, 2015

OSPF Default Routing

OSPF Default Routing
Case 1 - Advertise Route when default route in routing table

R6

router ospf 10
network 6.6.6.6 0.0.0.0 area 3
network 16.0.0.0 0.0.0.255 area 3
default-information originate metric 60 metric-type 1

ip route 0.0.0.0 0.0.0.0 Null0

O*E1 0.0.0.0/0 [110/61] via 16.0.0.6, 00:00:10, FastEthernet0/0

Case 2 - Advertise Route when default route not in routing table

now we will remove Default Route, So R6 will not have any default route in Routing Table.

Other area will not have any default route.

router ospf 10

default-information originate always metric 40

O*E2 0.0.0.0/0 [110/40] via 16.0.0.6, 00:01:50, FastEthernet0/0

Case 3 - Default route generate only when Loopback 1 66.6.6.6/32 is in routing table.

R6#sh ip int br | in Loopback1

Loopback1 66.6.6.6 YES NVRAM up up

router ospf 10

default-information originate route-map loop1

//ip route 0.0.0.0 0.0.0.0 Null0 this route is not required //

route-map loop1 permit 10

match ip address 1

access-list 1 permit 66.6.6.6

O*E2 0.0.0.0/0 [110/1] via 16.0.0.6, 00:00:01, FastEthernet0/0

Now in R6

int lo1

shut

%LINK-5-CHANGED: Interface Loopback1, changed state to administratively down

route will disappear as R6 does not have 66.6.6.6/32 in his routing table.

R1#sh ip route 0.0.0.0

% Network not in table

R1#

Case 4- Reliable Conditional Default Routing

track 1 ip sla 1 reachability

router ospf 10

default-information originate always route-map track

ip route 106.106.106.106 255.255.255.255 Null0 track 1

ip sla 1

icmp-echo 9.9.9.9

ip sla schedule 1 life forever start-time now

route-map track permit 10

match ip address prefix-list track

R1#sh ip route 0.0.0.0

Routing entry for 0.0.0.0/0, supernet

Known via "ospf 10", distance 110, metric 1, candidate default path

Tag 10, type extern 2, forward metric 1

Last update from 16.0.0.6 on FastEthernet0/0, 00:01:49 ago

Routing Descriptor Blocks:

* 16.0.0.6, from 66.6.6.6, 00:01:49 ago, via FastEthernet0/0

Route metric is 1, traffic share count is 1

Route tag 10

R1#

Now we will shut lo0 in R9

int lo0

shut

Loopback0 9.9.9.9 YES NVRAM administratively down down

R6#sh track

Track 1

IP SLA 1 reachability

Reachability is Down

3 changes, last change 00:00:33

Latest operation return code: Timeout

Tracked by:

Static IP Routing 0

Now we can see now in R1 no default route is from R6

R1#sh ip route 0.0.0.0

% Network not in table

R1#

Wednesday, August 26, 2015

OSPF - Forwarding Address

Case 1 - Understanding of forwarding address
Case 2. Suppressing forwarding address to make route reachable.

Case 1 - Understanding of forwarding address
R6

interface Loopback1
ip address 66.6.6.6 255.255.255.255
!
interface Loopback10
ip address 66.6.7.7 255.255.255.255

router ospf 10

area 3 nssa

redistribute connected subnets route-map fasup

route-map fasup permit 10

match interface Loopback1 Loopback10

With OSPF database lookups on external routes, the Forward Address
field determines who the next recursive lookup should be performed toward.

With typical Type-5 External LSAs,the forward address is normally set to 0.0.0.0. This means that the next lookup should be performed toward the Advertising Router.
As in N2 route FA is router,s address.

in R6

Type-7 AS External Link States (Area 3)

Link ID ADV Router Age Seq# Checksum Tag

66.6.6.6 69.4.1.1 876 0x80000001 0x00B3FA 0

66.6.7.7 69.4.1.1 876 0x80000001 0x009E0E 0

R6#

R5#sh ip route | in 66

66.0.0.0/32 is subnetted, 2 subnets

O N2 66.6.6.6 [110/20] via 56.0.0.6, 00:06:14, FastEthernet0/1

O N2 66.6.7.7 [110/20] via 56.0.0.6, 00:06:14, FastEthernet0/1

R5#sh ip ospf database external 66.6.6.6

OSPF Router with ID (55.5.5.5) (Process ID 10)

Type-5 AS External Link States

LS age: 486

Options: (No TOS-capability, DC, Upward)

LS Type: AS External Link

Link State ID: 66.6.6.6 (External Network Number )

Advertising Router: 55.5.5.5

LS Seq Number: 80000001

Checksum: 0x8A33

Length: 36

Network Mask: /32

Metric Type: 2 (Larger than any link state path)

MTID: 0

Metric: 20

Forward Address: 69.1.1.1

External Route Tag: 0

*************************

R5#sh ip ospf database nssa-external 66.6.6.6

*************************

OSPF Router with ID (55.5.5.5) (Process ID 10)

Type-7 AS External Link States (Area 3)

Routing Bit Set on this LSA in topology Base with MTID 0

LS age: 1114

Options: (No TOS-capability, Type 7/5 translation, DC, Upward)

LS Type: AS External Link

Link State ID: 66.6.6.6 (External Network Number )

Advertising Router: 69.4.1.1

LS Seq Number: 80000001

Checksum: 0xB3FA

Length: 36

Network Mask: /32

Metric Type: 2 (Larger than any link state path)

MTID: 0

Metric: 20

Forward Address: 69.1.1.1

External Route Tag: 0

*************************8

33.0.0.0/32 is subnetted, 1 subnets
O E2 33.33.33.33 [110/20] via 25.0.0.2, 00:01:03, FastEthernet0/0
[110/20] via 15.0.0.1, 00:01:03, FastEthernet2/0

R5#sh ip ospf database external 33.33.33.33

OSPF Router with ID (55.5.5.5) (Process ID 10)

Type-5 AS External Link States

Routing Bit Set on this LSA in topology Base with MTID 0

LS age: 136

Options: (No TOS-capability, DC, Upward)

LS Type: AS External Link

Link State ID: 33.33.33.33 (External Network Number )

Advertising Router: 39.1.4.1

LS Seq Number: 80000001

Checksum: 0x6985

Length: 36

Network Mask: /32

Metric Type: 2 (Larger than any link state path)

MTID: 0

Metric: 20

Forward Address: 0.0.0.0

External Route Tag: 0

R2

R2#sh ip ospf database external 66.6.6.6

OSPF Router with ID (2.2.2.2) (Process ID 10)

Type-5 AS External Link States

LS age: 27
Options: (No TOS-capability, DC, Upward)
LS Type: AS External Link
Link State ID: 66.6.6.6 (External Network Number )
Advertising Router: 55.5.5.5
LS Seq Number: 80000004
Checksum: 0x8436
Length: 36
Network Mask: /32
Metric Type: 2 (Larger than any link state path)
MTID: 0
Metric: 20
Forward Address: 69.1.1.1
External Route Tag: 0

Case 2. Suppressing forwarding address to make route reachable.

In R2 66.6.6.6/32 is not reachable because forwarding address 69.1.1.1 is not in routing table.
But 66.6.6.6 is in OSPF database

R2#sh ip route 69.1.1.1
% Subnet not in table
R2#sh ip route 66.6.6.6
% Network not in table
R2#

R2#sh ip ospf database external 66.6.6.6

OSPF Router with ID (2.2.2.2) (Process ID 10)

Type-5 AS External Link States

LS age: 27
Options: (No TOS-capability, DC, Upward)
LS Type: AS External Link
Link State ID: 66.6.6.6 (External Network Number )
Advertising Router: 55.5.5.5
LS Seq Number: 80000004
Checksum: 0x8436
Length: 36
Network Mask: /32
Metric Type: 2 (Larger than any link state path)
MTID: 0
Metric: 20
Forward Address: 69.1.1.1
External Route Tag: 0

to make FA 0.0.0.0 we will suppress this on ABR ( R5)

R5

router ospf 10
area 0 filter-list prefix test in
area 3 nssa translate type7 suppress-fa

to know about filter list click

now

R5#sh ip ospf database external 66.6.6.6

OSPF Router with ID (55.5.5.5) (Process ID 10)

Type-5 AS External Link States

LS age: 107
Options: (No TOS-capability, DC, Upward)
LS Type: AS External Link
Link State ID: 66.6.6.6 (External Network Number )
Advertising Router: 55.5.5.5
LS Seq Number: 80000005
Checksum: 0x61A0
Length: 36
Network Mask: /32
Metric Type: 2 (Larger than any link state path)
MTID: 0
Metric: 20
Forward Address: 0.0.0.0
External Route Tag: 0

R2

R2#sh ip route 66.6.6.6
Routing entry for 66.6.6.6/32
Known via "ospf 10", distance 110, metric 20, type extern 2, forward metric 1
Last update from 25.0.0.5 on FastEthernet0/0, 00:02:21 ago
Routing Descriptor Blocks:
* 25.0.0.5, from 55.5.5.5, 00:02:21 ago, via FastEthernet0/0

Route metric is 20, traffic share count is 1

R2#sh ip ospf database external 66.6.6.6

OSPF Router with ID (2.2.2.2) (Process ID 10)

Type-5 AS External Link States

Routing Bit Set on this LSA in topology Base with MTID 0
LS age: 180
Options: (No TOS-capability, DC, Upward)
LS Type: AS External Link
Link State ID: 66.6.6.6 (External Network Number )
Advertising Router: 55.5.5.5
LS Seq Number: 80000005
Checksum: 0x61A0
Length: 36
Network Mask: /32
Metric Type: 2 (Larger than any link state path)
MTID: 0
Metric: 20
Forward Address: 0.0.0.0 // Now this will follow next-hop recursion//
External Route Tag: 0

Tuesday, August 25, 2015

OSPF - Filtering LSA 3

See the Database entry before applying filter list

R5#sh ip ospf database summary 69.1.1.1

OSPF Router with ID (55.5.5.5) (Process ID 10)

Summary Net Link States (Area 0)

LS age: 366
Options: (No TOS-capability, DC, Upward)
LS Type: Summary Links(Network)
Link State ID: 69.1.1.1 (summary Network Number)
Advertising Router: 1.1.1.1
LS Seq Number: 80000001
Checksum: 0xD915
Length: 28
Network Mask: /32
MTID: 0 Metric: 2

LS age: 2
Options: (No TOS-capability, DC, Upward)
LS Type: Summary Links(Network)
Link State ID: 69.1.1.1 (summary Network Number)
Advertising Router: 55.5.5.5
LS Seq Number: 80000001
Checksum: 0x9D0F
Length: 28
Network Mask: /32
MTID: 0 Metric: 2

R5#

LSA 3 filtering

R5
router ospf 10
area 0 filter-list prefix test in

ip prefix-list test seq 5 deny 69.1.1.1/32

ip prefix-list test seq 10 deny 69.2.1.1/32

ip prefix-list test seq 15 permit 0.0.0.0/0 le 32

R5#sh ip ospf database summary 69.1.1.1

OSPF Router with ID (55.5.5.5) (Process ID 10) LSA 3

Summary Net Link States (Area 0)

LS age: 95

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 69.1.1.1 (summary Network Number)

Advertising Router: 1.1.1.1

LS Seq Number: 80000001

Checksum: 0xD915

Length: 28

Network Mask: /32

MTID: 0 Metric: 2

No entry from 55.5.5.5

**********************

R5#sh ip ospf database summary 69.2.1.1

***************************

OSPF Router with ID (55.5.5.5) (Process ID 10) LSA 3

Summary Net Link States (Area 0)

LS age: 141

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 69.2.1.1 (summary Network Number)

Advertising Router: 1.1.1.1

LS Seq Number: 80000001

Checksum: 0xCD20

Length: 28

Network Mask: /32

MTID: 0 Metric: 2

***************************

R5#sh ip ospf database summary 69.3.1.1

************************

OSPF Router with ID (55.5.5.5) (Process ID 10)

Summary Net Link States (Area 0) LSA 3

LS age: 1779

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 69.3.1.1 (summary Network Number)

Advertising Router: 1.1.1.1

LS Seq Number: 80000001

Checksum: 0xC12B

Length: 28

Network Mask: /32

MTID: 0 Metric: 2

LS age: 970

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 69.3.1.1 (summary Network Number)

Advertising Router: 55.5.5.5

LS Seq Number: 80000001

Checksum: 0x8525

Length: 28

Network Mask: /32

MTID: 0 Metric: 2

R5#

sh ip route

R5#sh ip route 69.1.1.1

Routing entry for 69.1.1.1/32

Known via "ospf 10", distance 110, metric 2, type intra area

Last update from 56.0.0.6 on FastEthernet0/1, 00:35:35 ago

Routing Descriptor Blocks:

* 56.0.0.6, from 69.4.1.1, 00:35:35 ago, via FastEthernet0/1

Route metric is 2, traffic share count is 1

R2#sh ip ospf database summary 69.1.1.1

OSPF Router with ID (2.2.2.2) (Process ID 10)

Summary Net Link States (Area 0)

Routing Bit Set on this LSA in topology Base with MTID 0

LS age: 1207

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 69.1.1.1 (summary Network Number)

Advertising Router: 1.1.1.1

LS Seq Number: 80000001

Checksum: 0xD915

Length: 28

Network Mask: /32

MTID: 0 Metric: 2

Summary Net Link States (Area 2)

LS age: 702

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 69.1.1.1 (summary Network Number)

Advertising Router: 2.2.2.2

LS Seq Number: 80000003

Checksum: 0xCB1B

Length: 28

Network Mask: /32

MTID: 0 Metric: 4

R2# sh ip route

O IA 69.1.1.1 [110/4] via 25.0.0.5, 00:12:52, FastEthernet0/0
[110/4] via 23.0.0.3, 00:12:52, FastEthernet0/1
O IA 69.2.1.1 [110/4] via 25.0.0.5, 00:12:52, FastEthernet0/0
[110/4] via 23.0.0.3, 00:12:52, FastEthernet0/1
O IA 69.3.1.1 [110/3] via 25.0.0.5, 00:34:17, FastEthernet0/0
O IA 69.4.1.1 [110/3] via 25.0.0.5, 00:34:17, FastEthernet0/0

Sunday, August 23, 2015

OSPF - Not So Stubby Area (NSSA) / Totally Stub

Lo2 66.1.0.1
l03 66.1.1.1
lo4 66.1.2.1
lo5 66.1.3.1

router ospf 10

auto-cost reference-bandwidth 1000

redistribute connected subnets route-map LOOP

network 6.6.6.6 0.0.0.0 area 3

route-map LOOP permit 10

match interface Loopback2 Loopback3 Loopback4 Loopback5

R5 & R6

Router ospf 10
Area 3 nssa

In NSSA LSA 7 Float
ABR convert LSA 7 into LSA 5
NSSA does not generate default route

R6# sh ip ospf database

OSPF Router with ID (66.6.6.6) (Process ID 10)

Router Link States (Area 3)

Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 2094 (DNA) 0x8000000B 0x009C53 1
55.5.5.5 55.5.5.5 1 (DNA) 0x8000004A 0x0058EA 3
66.6.6.6 66.6.6.6 21 0x8000004D 0x0051DC 3

Summary Net Link States (Area 3)

Link ID ADV Router Age Seq# Checksum
9.9.9.9 1.1.1.1 2094 (DNA) 0x8000000A 0x008D32
9.9.9.9 55.5.5.5 8 (DNA) 0x80000003 0x00A0E7
::::::::::::::::;;;

Type-7 AS External Link States (Area 3) LSA 7

Link ID ADV Router Age Seq# Checksum Tag
66.1.0.0 66.6.6.6 52 0x80000001 0x0044A2 0
66.1.1.0 66.6.6.6 52 0x80000001 0x0039AC 0
66.1.2.0 66.6.6.6 52 0x80000001 0x002EB6 0
66.1.3.0 66.6.6.6 52 0x80000001 0x0023C0 0
R6#

In R5

R5#sh ip ospf database

OSPF Router with ID (55.5.5.5) (Process ID 10)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 1163 0x8000003B 0x00F995 2
2.2.2.2 2.2.2.2 902 0x8000005F 0x00427A 3
39.1.4.1 39.1.4.1 1616 0x8000004E 0x005564 3
44.4.4.4 44.4.4.4 848 0x80000035 0x00A898 1
55.5.5.5 55.5.5.5 218 0x8000005A 0x00145C 3

Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum
13.0.0.3 39.1.4.1 623 0x80000020 0x008923
15.0.0.1 1.1.1.1 1163 0x80000010 0x00DAF1
23.0.0.3 39.1.4.1 1616 0x80000015 0x004F5A
25.0.0.5 55.5.5.5 780 0x8000000D 0x002358
34.0.0.4 44.4.4.4 849 0x80000022 0x00361F

Summary Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum
5.5.5.5 55.5.5.5 1295 0x8000000D 0x003A9B
6.6.6.6 55.5.5.5 207 0x80000001 0x00884B
:::::::::::::::::::::::::::

Summary ASB Link States (Area 0)

Link ID ADV Router Age Seq# Checksum
172.16.0.9 2.2.2.2 666 0x80000002 0x005ED7
172.16.0.9 44.4.4.4 853 0x80000002 0x00B915

Router Link States (Area 3)

Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 2093 (DNA) 0x8000000B 0x009C53 1
55.5.5.5 55.5.5.5 217 0x8000004A 0x0058EA 3
66.6.6.6 66.6.6.6 1 (DNA) 0x8000004D 0x0051DC 3

Summary Net Link States (Area 3)

Link ID ADV Router Age Seq# Checksum
9.9.9.9 1.1.1.1 2093 (DNA) 0x8000000A 0x008D32
9.9.9.9 55.5.5.5 227 0x80000003 0x00A0E7
:::::::::::::::::::::::::::;;;

Type-7 AS External Link States (Area 3) LSA 7

Link ID ADV Router Age Seq# Checksum Tag
66.1.0.0 66.6.6.6 30 (DNA) 0x80000001 0x0044A2 0
66.1.1.0 66.6.6.6 30 (DNA) 0x80000001 0x0039AC 0
66.1.2.0 66.6.6.6 30 (DNA) 0x80000001 0x002EB6 0
66.1.3.0 66.6.6.6 30 (DNA) 0x80000001 0x0023C0 0

Type-5 AS External Link States LSA 5

Link ID ADV Router Age Seq# Checksum Tag
66.1.0.0 55.5.5.5 209 0x80000001 0x0051AD 0
66.1.1.0 55.5.5.5 210 0x80000001 0x0046B7 0
66.1.2.0 55.5.5.5 210 0x80000001 0x003BC1 0
66.1.3.0 55.5.5.5 210 0x80000001 0x0030CB 0
99.9.9.9 172.16.0.9 803 0x80000002 0x001429 0
R5#

Router Link States (Area 2)

Link ID ADV Router Age Seq# Checksum Link count

2.2.2.2 2.2.2.2 1892 0x80000038 0x00CA5B 3

44.4.4.4 44.4.4.4 1324 0x8000004D 0x00CDD8 2

172.16.0.9 172.16.0.9 1022 0x8000004C 0x00C586 3

Summary Net Link States (Area 2)

Link ID ADV Router Age Seq# Checksum

:::::::::::::::::::

56.0.0.0 44.4.4.4 1587 0x8000000D 0x00EBB5

102.1.0.0 2.2.2.2 1892 0x8000000D 0x00FFC0

102.1.0.0 44.4.4.4 1827 0x8000000D 0x00C8BC

Summary ASB Link States (Area 2) LSA 4

Link ID ADV Router Age Seq# Checksum

55.5.5.5 2.2.2.2 447 0x80000001 0x0030B3

55.5.5.5 44.4.4.4 447 0x80000001 0x00F8AF

Type-5 AS External Link States LSA 5

Link ID ADV Router Age Seq# Checksum Tag

66.1.0.0 55.5.5.5 432 0x80000001 0x0051AD 0

66.1.1.0 55.5.5.5 432 0x80000001 0x0046B7 0

66.1.2.0 55.5.5.5 432 0x80000001 0x003BC1 0

66.1.3.0 55.5.5.5 432 0x80000001 0x0030CB 0

99.9.9.9 172.16.0.9 1022 0x80000002 0x001429 0

R2#

sh ip route

66.0.0.0/24 is subnetted, 4 subnets

O N2 66.1.0.0 [110/20] via 56.0.0.6, 00:09:29, FastEthernet0/1

O N2 66.1.1.0 [110/20] via 56.0.0.6, 00:09:29, FastEthernet0/1

O N2 66.1.2.0 [110/20] via 56.0.0.6, 00:09:29, FastEthernet0/1

O N2 66.1.3.0 [110/20] via 56.0.0.6, 00:09:29, FastEthernet0/1

99.0.0.0/32 is subnetted, 1 subnets

N2 NSSA type 2 route , same as E2

66.0.0.0/24 is subnetted, 4 subnets

O E2 66.1.0.0 [110/20] via 25.0.0.5, 00:08:46, FastEthernet0/0

O E2 66.1.1.0 [110/20] via 25.0.0.5, 00:08:46, FastEthernet0/0

O E2 66.1.2.0 [110/20] via 25.0.0.5, 00:08:46, FastEthernet0/0

O E2 66.1.3.0 [110/20] via 25.0.0.5, 00:08:46, FastEthernet0/0

66.0.0.0/24 is subnetted, 4 subnets

O E2 66.1.0.0 [110/20] via 172.16.0.2, 00:10:41, Tunnel0

O E2 66.1.1.0 [110/20] via 172.16.0.2, 00:10:41, Tunnel0

O E2 66.1.2.0 [110/20] via 172.16.0.2, 00:10:41, Tunnel0

O E2 66.1.3.0 [110/20] via 172.16.0.2, 00:10:41, Tunnel0

R5 & R6

Router ospf 10
Area 3 nssa no-summary

R6# sh ip route ospf

::::::::::::::::::

Gateway of last resort is 56.0.0.5 to network 0.0.0.0

O*IA 0.0.0.0/0 [110/11] via 56.0.0.5, 00:01:41, FastEthernet0/1

5.0.0.0/32 is subnetted, 1 subnets

O 5.5.5.5 [110/11] via 56.0.0.5, 00:01:41, FastEthernet0/1

R6#

Here we can see a default route..

R6#sh ip ospf database

OSPF Router with ID (66.6.6.6) (Process ID 10)

Router Link States (Area 3) LSA 1

Link ID ADV Router Age Seq# Checksum Link count

1.1.1.1 1.1.1.1 2094 (DNA) 0x8000000B 0x009C53 1

55.5.5.5 55.5.5.5 1 (DNA) 0x8000004A 0x0058EA 3

66.6.6.6 66.6.6.6 1166 0x8000004D 0x0051DC 3

Summary Net Link States (Area 3) LSA 3

Link ID ADV Router Age Seq# Checksum

0.0.0.0 55.5.5.5 1 (DNA) 0x80000001 0x00DE11

:::::::::::::::::

:::::::::::::

Type-7 AS External Link States (Area 3) LSA 7

Link ID ADV Router Age Seq# Checksum Tag

66.1.0.0 66.6.6.6 1198 0x80000001 0x0044A2 0

66.1.1.0 66.6.6.6 1198 0x80000001 0x0039AC 0

66.1.2.0 66.6.6.6 1198 0x80000001 0x002EB6 0

66.1.3.0 66.6.6.6 1198 0x80000001 0x0023C0 0

R6#

Default route in NSSA.

R5
router ospf 10
no discard-route internal
auto-cost reference-bandwidth 1000
area 3 nssa default-information-originate
area 3 default-cost 300

R6

O*N2 0.0.0.0/0 [110/300] via 56.0.0.5, 00:00:08, FastEthernet0/1
5.0.0.0/32 is subnetted, 1 subnets

R5#sh ip ospf database nssa-external

OSPF Router with ID (55.5.5.5) (Process ID 10)

Type-7 AS External Link States (Area 3)

LS age: 782
Options: (No TOS-capability, No Type 7/5 translation, DC, Upward)
LS Type: AS External Link
Link State ID: 0.0.0.0 (External Network Number )
Advertising Router: 55.5.5.5
LS Seq Number: 80000002
Checksum: 0x69D4
Length: 36
Network Mask: /0
Metric Type: 2 (Larger than any link state path)
MTID: 0
Metric: 300
Forward Address: 0.0.0.0
External Route Tag: 0

OSPF - Stub and Totally Stub

STUB Area
1. Area 3 is stub
2. R9 Redistributing 99.9.9.9/32 into Ospf as E2 route

Stub Area does not have LSA 4 & LSA 5
in R5 & R6

router ospf 10
area 3 stub

R9

Lo10 99.9.9.9/32

router ospf 10
auto-cost reference-bandwidth 1000
redistribute connected metric 50 subnets route-map con

ip prefix-list con seq 5 permit 99.9.9.9/32
!
route-map con permit 10
match ip address prefix-list con

**************Database & Route************

R6#sh ip route

::::::::::::::

Gateway of last resort is 56.0.0.5 to network 0.0.0.0

O*IA 0.0.0.0/0 [110/11] via 56.0.0.5, 00:09:03, FastEthernet0/1

5.0.0.0/32 is subnetted, 1 subnets

O 5.5.5.5 [110/11] via 56.0.0.5, 00:09:03, FastEthernet0/1

6.0.0.0/32 is subnetted, 1 subnets

C 6.6.6.6 is directly connected, Loopback0

9.0.0.0/32 is subnetted, 1 subnets

O IA 9.9.9.9 [110/10021] via 56.0.0.5, 00:09:03, FastEthernet0/1

13.0.0.0/24 is subnetted, 1 subnets

O IA 13.0.0.0 [110/30] via 56.0.0.5, 00:09:03, FastEthernet0/1

15.0.0.0/24 is subnetted, 1 subnets

O IA 15.0.0.0 [110/20] via 56.0.0.5, 00:09:03, FastEthernet0/1

16.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C 16.0.0.0/24 is directly connected, FastEthernet0/0

L 16.0.0.6/32 is directly connected, FastEthernet0/0

23.0.0.0/24 is subnetted, 1 subnets

O IA 23.0.0.0 [110/30] via 56.0.0.5, 00:09:04, FastEthernet0/1

25.0.0.0/24 is subnetted, 1 subnets

O IA 25.0.0.0 [110/20] via 56.0.0.5, 00:09:04, FastEthernet0/1

34.0.0.0/24 is subnetted, 1 subnets

O IA 34.0.0.0 [110/31] via 56.0.0.5, 00:09:04, FastEthernet0/1

55.0.0.0/32 is subnetted, 1 subnets

O IA 55.5.5.5 [110/11] via 56.0.0.5, 00:09:04, FastEthernet0/1

56.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C 56.0.0.0/24 is directly connected, FastEthernet0/1

L 56.0.0.6/32 is directly connected, FastEthernet0/1

66.0.0.0/8 is variably subnetted, 9 subnets, 2 masks

C 66.1.0.0/24 is directly connected, Loopback2

L 66.1.0.1/32 is directly connected, Loopback2

C 66.1.1.0/24 is directly connected, Loopback3

L 66.1.1.1/32 is directly connected, Loopback3

C 66.1.2.0/24 is directly connected, Loopback4

L 66.1.2.1/32 is directly connected, Loopback4

C 66.1.3.0/24 is directly connected, Loopback5

L 66.1.3.1/32 is directly connected, Loopback5

C 66.6.6.6/32 is directly connected, Loopback1

102.0.0.0/24 is subnetted, 1 subnets

O IA 102.1.0.0 [110/21] via 56.0.0.5, 00:09:05, FastEthernet0/1

172.16.0.0/32 is subnetted, 3 subnets

O IA 172.16.0.2 [110/20] via 56.0.0.5, 00:09:05, FastEthernet0/1

O IA 172.16.0.4 [110/31] via 56.0.0.5, 00:09:05, FastEthernet0/1

O IA 172.16.0.9 [110/10020] via 56.0.0.5, 00:09:05, FastEthernet0/1

************

R6# sh ip ospf database

OSPF Router with ID (66.6.6.6) (Process ID 10)

Router Link States (Area 3) LSA 1

Link ID ADV Router Age Seq# Checksum Link count

1.1.1.1 1.1.1.1 2094 (DNA) 0x8000000B 0x009C53 1

55.5.5.5 55.5.5.5 132 (DNA) 0x80000041 0x00DC79 3

66.6.6.6 66.6.6.6 636 0x80000043 0x0060B7 4

Summary Net Link States (Area 3) LSA 3

Link ID ADV Router Age Seq# Checksum

0.0.0.0 55.5.5.5 158 (DNA) 0x80000001 0x0057A0

9.9.9.9 1.1.1.1 2094 (DNA) 0x8000000A 0x008D32

9.9.9.9 55.5.5.5 157 (DNA) 0x80000010 0x00FE84

13.0.0.0 1.1.1.1 2094 (DNA) 0x8000000A 0x001405

13.0.0.0 55.5.5.5 157 (DNA) 0x8000000D 0x005477

15.0.0.0 1.1.1.1 2094 (DNA) 0x8000000A 0x00F91D

15.0.0.0 55.5.5.5 157 (DNA) 0x8000000D 0x00D5FD

23.0.0.0 1.1.1.1 2094 (DNA) 0x8000000A 0x00F50F

23.0.0.0 55.5.5.5 157 (DNA) 0x80000010 0x00CBF2

::::::::::::::::::;;

We can see no LSA 4 & 5 in the AREA 3 ( No Route for 99.9.9.9/32 and one default route is installed in routing tale,

while in R5

R5# sh ip route 99.9.9.9
Routing entry for 99.9.9.9/32
Known via "ospf 10", distance 110, metric 50, type extern 2, forward metric 10010
Last update from 25.0.0.2 on FastEthernet0/0, 00:08:16 ago
Routing Descriptor Blocks:
* 25.0.0.2, from 172.16.0.9, 00:08:16 ago, via FastEthernet0/0
Route metric is 50, traffic share count is 1
R5#

R5#sh ip ospf database

OSPF Router with ID (55.5.5.5) (Process ID 10)

Router Link States (Area 0) LSA 1

Link ID ADV Router Age Seq# Checksum Link count

1.1.1.1 1.1.1.1 1120 0x8000003A 0x00FB94 2

2.2.2.2 2.2.2.2 878 0x8000005E 0x004479 3

39.1.4.1 39.1.4.1 1590 0x8000004D 0x005763 3

44.4.4.4 44.4.4.4 802 0x80000034 0x00AA97 1

55.5.5.5 55.5.5.5 767 0x80000058 0x001262 3

Net Link States (Area 0) LSA 2

Link ID ADV Router Age Seq# Checksum

13.0.0.3 39.1.4.1 576 0x8000001F 0x008B22

15.0.0.1 1.1.1.1 1120 0x8000000F 0x00DCF0

23.0.0.3 39.1.4.1 1590 0x80000014 0x005159

25.0.0.5 55.5.5.5 767 0x8000000C 0x002557

34.0.0.4 44.4.4.4 802 0x80000021 0x00381E

Summary Net Link States (Area 0) LSA 3

Link ID ADV Router Age Seq# Checksum

5.5.5.5 55.5.5.5 1287 0x8000000C 0x003C9A

6.6.6.6 55.5.5.5 902 0x80000003 0x00844D

9.9.9.9 2.2.2.2 1624 0x8000000C 0x00A22B

9.9.9.9 44.4.4.4 1564 0x8000000C 0x00FD68

16.0.0.0 1.1.1.1 1123 0x8000000B 0x00EA2A

16.0.0.0 55.5.5.5 902 0x80000003 0x0023AD

56.0.0.0 55.5.5.5 1290 0x8000000C 0x00A207

172.16.0.2 2.2.2.2 1624 0x8000000C 0x009DCD

172.16.0.2 44.4.4.4 1564 0x8000000C 0x00F80B

172.16.0.4 2.2.2.2 1624 0x8000000C 0x008AA7

172.16.0.4 44.4.4.4 299 0x80000025 0x00B16E

172.16.0.9 2.2.2.2 1624 0x8000000C 0x0058D4

172.16.0.9 44.4.4.4 1564 0x8000000C 0x00B312

Summary ASB Link States (Area 0) LSA 4

Link ID ADV Router Age Seq# Checksum

172.16.0.9 2.2.2.2 623 0x80000001 0x0060D6

172.16.0.9 44.4.4.4 624 0x80000001 0x00BB14

Router Link States (Area 3) LSA1

Link ID ADV Router Age Seq# Checksum Link count

1.1.1.1 1.1.1.1 2093 (DNA) 0x8000000B 0x009C53 1

55.5.5.5 55.5.5.5 1049 0x80000041 0x00DC79 3

66.6.6.6 66.6.6.6 1 (DNA) 0x80000043 0x0060B7 4

Summary Net Link States (Area 3) LSA 3

Link ID ADV Router Age Seq# Checksum

0.0.0.0 55.5.5.5 1075 0x80000001 0x0057A0

9.9.9.9 1.1.1.1 2093 (DNA) 0x8000000A 0x008D32

9.9.9.9 55.5.5.5 771 0x80000011 0x00FC85

13.0.0.0 1.1.1.1 2093 (DNA) 0x8000000A 0x001405

13.0.0.0 55.5.5.5 1075 0x8000000D 0x005477

15.0.0.0 1.1.1.1 2093 (DNA) 0x8000000A 0x00F91D

15.0.0.0 55.5.5.5 1075 0x8000000D 0x00D5FD

23.0.0.0 1.1.1.1 2093 (DNA) 0x8000000A 0x00F50F

23.0.0.0 55.5.5.5 771 0x80000011 0x00C9F3

25.0.0.0 1.1.1.1 2093 (DNA) 0x8000000A 0x00DB27

25.0.0.0 55.5.5.5 1075 0x8000000D 0x005376

34.0.0.0 1.1.1.1 2093 (DNA) 0x8000000A 0x000CF6

34.0.0.0 55.5.5.5 1075 0x8000000D 0x004C69

55.5.5.5 1.1.1.1 2093 (DNA) 0x8000000A 0x00548A

55.5.5.5 55.5.5.5 1075 0x8000000D 0x00CBD9

102.1.0.0 1.1.1.1 2093 (DNA) 0x8000000A 0x00ECC6

102.1.0.0 55.5.5.5 772 0x80000011 0x005C1A

172.16.0.2 1.1.1.1 2093 (DNA) 0x8000000A 0x0088D4

172.16.0.2 55.5.5.5 772 0x80000011 0x00F728

172.16.0.4 1.1.1.1 2093 (DNA) 0x8000000A 0x001A4A

172.16.0.4 55.5.5.5 1075 0x8000000D 0x005ABC

172.16.0.9 1.1.1.1 2093 (DNA) 0x8000000A 0x0043DB

172.16.0.9 55.5.5.5 772 0x80000011 0x00B22F

Type-5 AS External Link States LSA 5

Link ID ADV Router Age Seq# Checksum Tag

99.9.9.9 172.16.0.9 630 0x80000001 0x001628 0

R5#

****Area 3 does not have LSA 4 and LSA 5

Totally stub

in R5 & R6

Router ospf 10
area 3 stub no-summary

R6

O*IA 0.0.0.0/0 [110/11] via 56.0.0.5, 00:02:11, FastEthernet0/1
5.0.0.0/32 is subnetted, 1 subnets
O 5.5.5.5 [110/11] via 56.0.0.5, 00:02:11, FastEthernet0/1
R6#

we can see there is no inter-area route
R6#sh ip ospf database

OSPF Router with ID (66.6.6.6) (Process ID 10)

Router Link States (Area 3)

Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 2094 (DNA) 0x8000000B 0x009C53 1
55.5.5.5 55.5.5.5 1 (DNA) 0x80000046 0x00D27E 3
66.6.6.6 66.6.6.6 223 0x80000048 0x00CD6F 3

Summary Net Link States (Area 3)

Link ID ADV Router Age Seq# Checksum
0.0.0.0 55.5.5.5 638 (DNA) 0x80000003 0x0053A2

OSPF - Summarization

Internal Summarization (Intra Area )
OSPF Internal Summarization

R5 & R6 (Border Router for Area 3)

Sh ip route ospf
66.0.0.0/32 is subnetted, 4 subnets
O 66.1.0.1 [110/11] via 56.0.0.6, 00:00:22, FastEthernet0/1
O 66.1.1.1 [110/11] via 56.0.0.6, 00:00:22, FastEthernet0/1
O 66.1.2.1 [110/11] via 56.0.0.6, 00:00:22, FastEthernet0/1

O 66.1.3.1 [110/11] via 56.0.0.6, 00:00:22, FastEthernet0/1

Summarization is done on Area Border routers only.

A summary route will only be advertised if you have at least one subnet that falls within the summary range.
ABR that creates the summary route will create a null0 interface to prevent loops

router ospf 10
auto-cost reference-bandwidth 1000
area 3 range 66.1.0.0 255.255.0.0

Now in R5

66.0.0.0/8 is variably subnetted, 5 subnets, 2 masks

O 66.1.0.0/16 is a summary, 00:08:42, Null0

O 66.1.0.1/32 [110/11] via 56.0.0.6, 00:08:42, FastEthernet0/1

O 66.1.1.1/32 [110/11] via 56.0.0.6, 00:08:42, FastEthernet0/1

O 66.1.2.1/32 [110/11] via 56.0.0.6, 00:08:42, FastEthernet0/1

O 66.1.3.1/32 [110/11] via 56.0.0.6, 00:08:42, FastEthernet0/1

R5#sh ip ospf database summary 66.1.0.0 adv-router 55.5.5.5

OSPF Router with ID (55.5.5.5) (Process ID 10)

Summary Net Link States (Area 0)

LS age: 1330

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(Network)

Link State ID: 66.1.0.0 (summary Network Number)

Advertising Router: 55.5.5.5

LS Seq Number: 80000001

Checksum: 0x3474

Length: 28

Network Mask: /16

MTID: 0 Metric: 11

R5#

66.0.0.0/8 is variably subnetted, 5 subnets, 2 masks

O IA 66.1.0.0/16 [110/21] via 25.0.0.5, 00:08:14, FastEthernet0/0

O IA 66.1.0.1/32 [110/31] via 25.0.0.5, 00:00:54, FastEthernet0/0

[110/31] via 23.0.0.3, 00:00:54, FastEthernet0/1

O IA 66.1.1.1/32 [110/31] via 25.0.0.5, 00:00:54, FastEthernet0/0

[110/31] via 23.0.0.3, 00:00:54, FastEthernet0/1

O IA 66.1.2.1/32 [110/31] via 25.0.0.5, 00:00:54, FastEthernet0/0

[110/31] via 23.0.0.3, 00:00:54, FastEthernet0/1

O IA 66.1.3.1/32 [110/31] via 25.0.0.5, 00:00:55, FastEthernet0/0

[110/31] via 23.0.0.3, 00:00:55, FastEthernet0/1

in R9

66.0.0.0/8 is variably subnetted, 5 subnets, 2 masks

O IA 66.1.0.0/16 [110/10021] via 172.16.0.2, 00:11:20, Tunnel0

O IA 66.1.0.1/32 [110/10031] via 172.16.0.2, 00:04:00, Tunnel0

O IA 66.1.1.1/32 [110/10031] via 172.16.0.2, 00:04:00, Tunnel0

O IA 66.1.2.1/32 [110/10031] via 172.16.0.2, 00:04:00, Tunnel0

O IA 66.1.3.1/32 [110/10031] via 172.16.0.2, 00:04:01, Tunnel0

Discard Routes

R5(config)#router ospf 10

R5(config-router)#no discard-route internal

[110/21] via 15.0.0.1, 00:00:35, FastEthernet2/0

66.0.0.0/32 is subnetted, 4 subnets

O 66.1.0.1 [110/11] via 56.0.0.6, 00:00:35, FastEthernet0/1

O 66.1.1.1 [110/11] via 56.0.0.6, 00:00:35, FastEthernet0/1

O 66.1.2.1 [110/11] via 56.0.0.6, 00:00:35, FastEthernet0/1

O 66.1.3.1 [110/11] via 56.0.0.6, 00:00:35, FastEthernet0/1

Nw we don't have 66.1.0.0/16 is a summary, 00:08:42, Null0 in routing table.

OSPF External Summarization

In R6

Lo2 66.1.0.1
l03 66.1.1.1
lo4 66.1.2.1
lo5 66.1.3.1

router ospf 10

auto-cost reference-bandwidth 1000

redistribute connected subnets route-map LOOP

network 6.6.6.6 0.0.0.0 area 3

route-map LOOP permit 10

match interface Loopback2 Loopback3 Loopback4 Loopback5

In R5

R5#sh ip route ospf | in 66.1

O E2 66.1.0.0 [110/20] via 56.0.0.6, 00:30:02, FastEthernet0/1

O E2 66.1.1.0 [110/20] via 56.0.0.6, 00:30:02, FastEthernet0/1

O E2 66.1.2.0 [110/20] via 56.0.0.6, 00:30:02, FastEthernet0/1

O E2 66.1.3.0 [110/20] via 56.0.0.6, 00:30:02, FastEthernet0/1

R5#

R2#sh ip route ospf | in 66.1

O E2 66.1.0.0 [110/20] via 25.0.0.5, 00:39:15, FastEthernet0/0

O E2 66.1.1.0 [110/20] via 25.0.0.5, 00:39:15, FastEthernet0/0

O E2 66.1.2.0 [110/20] via 25.0.0.5, 00:39:14, FastEthernet0/0

O E2 66.1.3.0 [110/20] via 25.0.0.5, 00:39:14, FastEthernet0/0

R2#

R9#sh ip route | in 66.1

O E2 66.1.0.0 [110/20] via 172.16.0.2, 00:39:50, Tunnel0

O E2 66.1.1.0 [110/20] via 172.16.0.2, 00:39:49, Tunnel0

O E2 66.1.2.0 [110/20] via 172.16.0.2, 00:39:48, Tunnel0

O E2 66.1.3.0 [110/20] via 172.16.0.2, 00:39:48, Tunnel0

R9#

*************************DATABASE ******************

*******************************************************

R5#sh ip ospf database

OSPF Router with ID (55.5.5.5) (Process ID 10)

Router Link States (Area 0) LSA -1

Link ID ADV Router Age Seq# Checksum Link count

1.1.1.1 1.1.1.1 1466 0x80000038 0x00FF92 2

2.2.2.2 2.2.2.2 1215 0x8000005C 0x004877 3

39.1.4.1 39.1.4.1 1971 0x8000004B 0x005B61 3

44.4.4.4 44.4.4.4 1165 0x80000032 0x00AE95 1

55.5.5.5 55.5.5.5 1178 0x80000056 0x001660 3

Net Link States (Area 0) LSA 2 ( DR)

Link ID ADV Router Age Seq# Checksum

13.0.0.3 39.1.4.1 962 0x8000001D 0x008F20

15.0.0.1 1.1.1.1 1466 0x8000000D 0x00E0EE

23.0.0.3 39.1.4.1 1971 0x80000012 0x005557

25.0.0.5 55.5.5.5 1178 0x8000000A 0x002955

34.0.0.4 44.4.4.4 1165 0x8000001F 0x003C1C

Summary Net Link States (Area 0) LSA 3

Link ID ADV Router Age Seq# Checksum

5.5.5.5 1.1.1.1 1466 0x80000009 0x0047C0

5.5.5.5 55.5.5.5 1700 0x8000000A 0x004098

6.6.6.6 1.1.1.1 1476 0x80000009 0x00B459

6.6.6.6 55.5.5.5 1700 0x8000000A 0x007654

9.9.9.9 2.2.2.2 1978 0x8000000A 0x00A629

9.9.9.9 44.4.4.4 1929 0x8000000A 0x000266

16.0.0.0 1.1.1.1 1477 0x80000009 0x00EE28

16.0.0.0 55.5.5.5 1701 0x8000000A 0x0015B4

56.0.0.0 1.1.1.1 1477 0x80000009 0x00499B

56.0.0.0 55.5.5.5 1702 0x8000000A 0x00A605

172.16.0.2 2.2.2.2 1980 0x8000000A 0x00A1CB

172.16.0.2 44.4.4.4 1931 0x8000000A 0x00FC09

172.16.0.4 2.2.2.2 1980 0x8000000A 0x008EA5

172.16.0.4 44.4.4.4 669 0x80000023 0x00B56C

172.16.0.9 2.2.2.2 1980 0x8000000A 0x005CD2

172.16.0.9 44.4.4.4 1932 0x8000000A 0x00B710

Summary ASB Link States (Area 0) LSA 4

Link ID ADV Router Age Seq# Checksum

66.6.6.6 1.1.1.1 485 0x80000002 0x009B3D

66.6.6.6 55.5.5.5 676 0x80000002 0x005F37

Router Link States (Area 3) LSA 1

Link ID ADV Router Age Seq# Checksum Link count

1.1.1.1 1.1.1.1 6 (DNA) 0x80000002 0x00AE4A 1

55.5.5.5 55.5.5.5 1707 0x8000003D 0x00C691 3

66.6.6.6 66.6.6.6 1 (DNA) 0x8000003D 0x0056A8 4

Net Link States (Area 3) LSA 2

Link ID ADV Router Age Seq# Checksum

16.0.0.6 66.6.6.6 1 (DNA) 0x80000001 0x006413

Summary Net Link States (Area 3) LSA 3

Link ID ADV Router Age Seq# Checksum

9.9.9.9 1.1.1.1 10 (DNA) 0x80000001 0x009F29 DNA DoNotAge

9.9.9.9 55.5.5.5 1205 0x8000000E 0x00E49E

13.0.0.0 1.1.1.1 10 (DNA) 0x80000001 0x0026FB

13.0.0.0 55.5.5.5 1717 0x8000000A 0x003C90

15.0.0.0 1.1.1.1 10 (DNA) 0x80000001 0x000C14

15.0.0.0 55.5.5.5 1717 0x8000000A 0x00BD17

23.0.0.0 1.1.1.1 10 (DNA) 0x80000001 0x000806

23.0.0.0 55.5.5.5 1205 0x8000000E 0x00B10D

25.0.0.0 1.1.1.1 10 (DNA) 0x80000001 0x00ED1E

25.0.0.0 55.5.5.5 1717 0x8000000A 0x003B8F

34.0.0.0 1.1.1.1 10 (DNA) 0x80000001 0x001EED

34.0.0.0 55.5.5.5 1717 0x8000000A 0x003482

55.5.5.5 1.1.1.1 10 (DNA) 0x80000001 0x006681

55.5.5.5 55.5.5.5 1717 0x8000000A 0x00B3F2

102.1.0.0 1.1.1.1 10 (DNA) 0x80000001 0x00FEBD

102.1.0.0 55.5.5.5 1205 0x8000000E 0x004433

172.16.0.2 1.1.1.1 10 (DNA) 0x80000001 0x009ACB

172.16.0.2 55.5.5.5 1205 0x8000000E 0x00DF41

172.16.0.4 1.1.1.1 10 (DNA) 0x80000001 0x002C41

172.16.0.4 55.5.5.5 1717 0x8000000A 0x0042D5

172.16.0.9 1.1.1.1 10 (DNA) 0x80000001 0x0055D2

172.16.0.9 55.5.5.5 1205 0x8000000E 0x009A48

Type-5 AS External Link States LSA 5

Link ID ADV Router Age Seq# Checksum Tag

66.1.0.0 66.6.6.6 483 0x80000002 0x00A95E 0

66.1.1.0 66.6.6.6 483 0x80000002 0x009E68 0

66.1.2.0 66.6.6.6 483 0x80000002 0x009372 0

66.1.3.0 66.6.6.6 483 0x80000002 0x00887C 0

R5#sh ip ospf database external 66.1.0.0

OSPF Router with ID (55.5.5.5) (Process ID 10)

Type-5 AS External Link States

Routing Bit Set on this LSA in topology Base with MTID 0
LS age: 470
Options: (No TOS-capability, DC, Upward)
LS Type: AS External Link
Link State ID: 66.1.0.0 (External Network Number )
Advertising Router: 66.6.6.6
LS Seq Number: 80000003
Checksum: 0xA75F
Length: 36
Network Mask: /24
Metric Type: 2 (Larger than any link state path)
MTID: 0
Metric: 20
Forward Address: 0.0.0.0

External Route Tag: 0

R5#

R2#sh ip ospf database

OSPF Router with ID (2.2.2.2) (Process ID 10)

Router Link States (Area 0)

THIS IS SAME AS R 5

Router Link States (Area 2) LSA 1

Link ID ADV Router Age Seq# Checksum Link count

2.2.2.2 2.2.2.2 862 0x80000036 0x00CE59 3

44.4.4.4 44.4.4.4 286 0x8000004B 0x00D1D6 2

172.16.0.9 172.16.0.9 509 0x80000049 0x00C58B 3

Summary Net Link States (Area 2) LSA 3

Link ID ADV Router Age Seq# Checksum

5.5.5.5 2.2.2.2 106 0x80000013 0x00B053

5.5.5.5 44.4.4.4 549 0x8000000B 0x008947

6.6.6.6 2.2.2.2 106 0x80000013 0x00E60F

6.6.6.6 44.4.4.4 286 0x8000000C 0x005972

13.0.0.0 2.2.2.2 862 0x8000000B 0x0058B1

13.0.0.0 44.4.4.4 39 0x8000001E 0x00329D

15.0.0.0 2.2.2.2 106 0x80000013 0x002ED1

15.0.0.0 44.4.4.4 40 0x80000020 0x007849

16.0.0.0 2.2.2.2 106 0x80000013 0x00856F

16.0.0.0 44.4.4.4 286 0x8000000C 0x009341

23.0.0.0 2.2.2.2 862 0x8000000B 0x007198

23.0.0.0 44.4.4.4 39 0x8000001E 0x00AF16

25.0.0.0 2.2.2.2 611 0x8000000D 0x0053B2

25.0.0.0 44.4.4.4 807 0x80000015 0x000CB6

34.0.0.0 2.2.2.2 862 0x8000000B 0x00EB12

34.0.0.0 44.4.4.4 1557 0x80000023 0x00B10E

55.5.5.5 2.2.2.2 106 0x80000013 0x0024AD

55.5.5.5 44.4.4.4 549 0x8000000B 0x00FCA1

56.0.0.0 2.2.2.2 106 0x80000013 0x0017BF

56.0.0.0 44.4.4.4 549 0x8000000B 0x00EFB3

102.1.0.0 2.2.2.2 862 0x8000000B 0x0004BE

102.1.0.0 44.4.4.4 806 0x8000000B 0x00CCBA

Summary ASB Link States (Area 2) LSA 4

Link ID ADV Router Age Seq# Checksum

66.6.6.6 2.2.2.2 1375 0x80000002 0x00E1E8

66.6.6.6 44.4.4.4 1557 0x80000002 0x004653

Type-5 AS External Link States LSA 5

Link ID ADV Router Age Seq# Checksum Tag

66.1.0.0 66.6.6.6 1751 0x80000002 0x00A95E 0

66.1.1.0 66.6.6.6 1751 0x80000002 0x009E68 0

66.1.2.0 66.6.6.6 1751 0x80000002 0x009372 0

66.1.3.0 66.6.6.6 1751 0x80000002 0x00887C 0

R2#

R2#sh ip ospf database asbr-summary

OSPF Router with ID (2.2.2.2) (Process ID 10)

Summary ASB Link States (Area 0)

Routing Bit Set on this LSA in topology Base with MTID 0

LS age: 1937

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(AS Boundary Router)

Link State ID: 66.6.6.6 (AS Boundary Router address)

Advertising Router: 1.1.1.1

LS Seq Number: 80000002

Checksum: 0x9B3D

Length: 28

Network Mask: /0

MTID: 0 Metric: 10

Routing Bit Set on this LSA in topology Base with MTID 0

LS age: 104

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(AS Boundary Router)

Link State ID: 66.6.6.6 (AS Boundary Router address)

Advertising Router: 55.5.5.5

LS Seq Number: 80000003

Checksum: 0x5D38

Length: 28

Network Mask: /0

MTID: 0 Metric: 10

Summary ASB Link States (Area 2)

LS age: 1936

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(AS Boundary Router)

Link State ID: 66.6.6.6 (AS Boundary Router address)

Advertising Router: 2.2.2.2

LS Seq Number: 80000002

Checksum: 0xE1E8

Length: 28

Network Mask: /0

MTID: 0 Metric: 20

Adv Router is not-reachable in topology Base with MTID 0

LS age: 92

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(AS Boundary Router)

Link State ID: 66.6.6.6 (AS Boundary Router address)

Advertising Router: 44.4.4.4

LS Seq Number: 80000003

Checksum: 0x4454

Length: 28

Network Mask: /0

MTID: 0 Metric: 21

R9#sh ip ospf database asbr-summary

OSPF Router with ID (172.16.0.9) (Process ID 10)

Summary ASB Link States (Area 2)

Routing Bit Set on this LSA in topology Base with MTID 0

LS age: 42

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(AS Boundary Router)

Link State ID: 66.6.6.6 (AS Boundary Router address)

Advertising Router: 2.2.2.2

LS Seq Number: 80000003

Checksum: 0xDFE9

Length: 28

Network Mask: /0

MTID: 0 Metric: 20

LS age: 228

Options: (No TOS-capability, DC, Upward)

LS Type: Summary Links(AS Boundary Router)

Link State ID: 66.6.6.6 (AS Boundary Router address)

Advertising Router: 44.4.4.4

LS Seq Number: 80000003

Checksum: 0x4454

Length: 28

Network Mask: /0

MTID: 0 Metric: 21