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passwd: helloworld

24/4/2011

OSPF - Part 6

Understanding OE1 and OE2 routes
OSPF အပိုင္းတြင္ အနည္းငယ္ရွဳပ္ေသာ ေနရာျဖစ္ပါတယ္။ မစခင္ အရင္ဆံုး ေအာက္ပါ concept 2ခုကို မွတ္ထားေစလိုပါတယ္။
OE1 = Redistribute cost + Cost to ASBR
OE2 = only Redistribute cost

Ok... ရွင္လင္းခ်င္း စတင္ပါမည္။

R1 က R2 နွင့္ R3 ကို OSPF area0 အတြင္းတြင္ ခ်ိတ္ဆက္ထားပါတယ္…
R2 နွင့္ R3 က R4 နွင့္ R5 ကို OSPF area1 အတြင္းတြင္ ခ်ိတ္ဆက္ထားပါတယ္…
R4 နွင့္ R5 က အျခား routing domain (EIGRP AS10) တြင္ရွိေသာ router R6 ကို ခ်ိတ္ဆက္ထားပါတယ္…
R6 က 10.1.6.0 /24 network ကို EIGRP ျဖင့္ advertise လုပ္ၿပီး ၄င္းnetworkအား R4 နွင့္ R5 တို႔က OSPF area အတြင္းသို႔ default parameters မ်ားျဖင့္ redistribute ျပန္လုပ္ပါတယ္။

R4:
router eigrp 10
 redistribute ospf 1 metric 100000 100 255 1 1500
!
router ospf 1
 redistribute eigrp 10 subnets

R5:
router eigrp 10
 redistribute ospf 1 metric 100000 100 255 1 1500
!
router ospf 1
 redistribute eigrp 10 subnets

Result: R1 က prefix 10.1.6.0 /24 ကို OSPF E2 (default) route အျဖစ္ R2 နွင့္ R3 ဆီမွ default cost (20 for EIGRP) ျဖင့္ရယူပါတယ္။ R1 ၏ routing table output ကို ေအာက္ပါအတိုင္း ေတြ႔နုိင္ပါတယ္…

R1#sh ip route ospf
     10.0.0.0 /24 is subnetted, 8 subnets
O E2    10.1.6.0 [110/20] via 10.1.13.3, 00:09:43, FastEthernet0/0.13
                         [110/20] via 10.1.12.2, 00:09:43, FastEthernet0/0.12
O IA    10.1.24.0 [110/2] via 10.1.12.2, 00:56:44, FastEthernet0/0.12
O E2    10.1.46.0 [110/20] via 10.1.13.3, 00:09:43, FastEthernet0/0.13
                          [110/20] via 10.1.12.2, 00:09:43, FastEthernet0/0.12
O IA    10.1.35.0 [110/2] via 10.1.13.3, 00:56:44, FastEthernet0/0.13
O E2    10.1.56.0 [110/20] via 10.1.13.3, 00:09:43, FastEthernet0/0.13
                          [110/20] via 10.1.12.2, 00:09:43, FastEthernet0/0.12

Examining the details of the route 10.1.6.0 /24 on R1.

R1#show ip route 10.1.6.0
Routing entry for 10.1.6.0 /24
  Known via "ospf 1", distance 110, metric 20, type extern 2, forward metric 2
  Last update from 10.1.13.3 on FastEthernet0/0.13, 00:12:03 ago
  Routing Descriptor Blocks:
    10.1.13.3, from 10.1.5.5, 00:12:03 ago, via FastEthernet0/0.13
      Route metric is 20, traffic share count is 1
  * 10.1.12.2, from 10.1.4.4, 00:12:03 ago, via FastEthernet0/0.12
      Route metric is 20, traffic share count is 1

Result တြင္ျမင္ရသည့္အတိုင္း 10.1.6.0 /24 network အတြက္ R2 နွင့္ R3 ကုိျဖတ္ၿပီးသြားလွ်င္ metric 20 ရွိမွာျဖစ္ပါတယ္။ Forward metric က “cost to ASBR(s)” (R1 to R4 or R5) ကိုေဖာ္ျပပါတယ္။ ထို႔အျပင္ OE2 route 2ခုလံုး metric value နွင့္ forward metric တို႔တူေနပါတယ္… ဘာလို႔ FastEthernet0/0.12 route ကို best route (other is Backup route) အျဖစ္ေရြးခ်ယ္ပါသလဲ??? အေျဖကရွင္းပါတယ္... TIE Breaker (use Router ID) ကို အသံုးျပဳသြားျခင္း ျဖစ္ပါတယ္။ ေနာက္တနည္းအားျဖင့္ metric type ကိုေျပာင္းျခင္း ျဖင့္လည္း path selection လုပ္နုိင္ပါတယ္။ R4 တြင္ျပင္ဆင္ၾကည့္ပါမယ္။

R4#config t
Enter configuration commands, one per line.  End with CNTL/Z.
R4(config)#router ospf 1
R4(config-router)#redistribute eigrp 10 subnets metric-type 1
R4(config-router)#end
R4#

Result:
R1#show ip route 10.1.6.0
Routing entry for 10.1.6.0 /24
  Known via "ospf 1", distance 110, metric 22, type extern 1
  Last update from 10.1.12.2 on FastEthernet0/0.12, 00:00:35 ago
  Routing Descriptor Blocks:
  * 10.1.12.2, from 10.1.4.4, 00:00:35 ago, via FastEthernet0/0.12
      Route metric is 22, traffic share count is 1

ယခုအခါတြင္ metic 22 (Redistribute cost + Cost to ASBR) ရွိေသာ E1 route 1ခုတည္းသာ install လုပ္ပါတယ္။ OSPF mechanism အရ E1 နွင့္ E2 ယွဥ္လွ်င္  E1 က E2 ထက္ cost ဘယ္ေလာက္မ်ားမ်ား E1ကို prefer လုပ္ပါတယ္။ တခုသတိထားရမွာက E1 route 2ခုရွိၿပီး metric တူေနပါက Load Balancing လုပ္နုိင္ပါတယ္။ ok… Metric ကိုထပ္ျပင္ၾကည့္ပါမယ္…

R4#config t
Enter configuration commands, one per line.  End with CNTL/Z.
R4(config)#router ospf 1
R4(config-router)#redistribute eigrp 10 subnets metric-type 1 metric 100
R4(config-router)#end
R4#

Result: still preferring E1
R1#show ip route 10.1.6.0
Routing entry for 10.1.6.0 /24
  Known via "ospf 1", distance 110, metric 102, type extern 1
  Last update from 10.1.12.2 on FastEthernet0/0.12, 00:00:15 ago
  Routing Descriptor Blocks:
  * 10.1.12.2, from 10.1.4.4, 00:00:15 ago, via FastEthernet0/0.12
      Route metric is 102, traffic share count is 1

R1 ၏ Link-state Database ထဲတြင္ E1 နွင့္ E2 2ခုလံုးေတြ႔ေနရ ေသာ္လည္း E1 route အား routing path အျဖစ္အသံုးျပဳထားသည္ကို ေတြ႔ရွိရပါမယ္…

R1#show ip ospf database external 10.1.6.0

 OSPF Router with ID (10.1.1.1) (Process ID 1)

                Type-5 AS External Link States

Routing Bit Set on this LSA
LS age: 64
  Options: (No TOS-capability, DC)
  LS Type: AS External Link
  Link State ID: 10.1.6.0 (External Network Number )
  Advertising Router: 10.1.4.4
  LS Seq Number: 80000003
  Checksum: 0x1C8E
  Length: 36
  Network Mask: /24
        Metric Type: 1 (Comparable directly to link state metric)
        TOS: 0
        Metric: 100
        Forward Address: 0.0.0.0
        External Route Tag: 0

  LS age: 1388
  Options: (No TOS-capability, DC)
  LS Type: AS External Link
  Link State ID: 10.1.6.0 (External Network Number )
  Advertising Router: 10.1.5.5
  LS Seq Number: 80000001
  Checksum: 0x7307
  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: 0

ref: Brian McGahan, CCIE #8593
22/4/2011

Download Hacker Evolution Untold

You need to install it on different directory (eg. D:\)...
Enjoy it!!!
passwd: iwannahack

21/4/2011

OSPF - Part 5

Redistribution external routes into OSPF
Basic concept of redistribution
Autonomous system (or) routing protocol မတူတဲ့အခါ တစ္ခုနွင့္တစ္ခု route လုပ္နုိင္ရန္ redistribution ကိုလုပ္ေပးရပါတယ္။ အဓိကသိရမွာက routing protocols ေတြရဲ႔ topology table ေတြက မတူတဲ့အတြက္ redistribution လုပ္တဲ့အခါမွာ IP routing table ကိုပဲအသံုးျပဳပါတယ္။

Example:

Injecting into EIGRP
ASBR1(config)# router eigrp 1
ASBR1(config-router)# redistribute ospf 1

Injecting into OSPF
ASBR1(config)# router ospf 1
ASBR1(config-router)# redistribute eigrp 1


Command syntax (optionals) for redistributing routes into OSPF
redistribute protocol [process-id | as-number][metric value][matric-type value][route-map name][subnets]

protocol: bgp, igrp, eigrp, isis, ospf, and rip
metric (optional):  ပံုမွန္အားျဖင့္default-metric command တြင္သတ္မွတ္ထားေသာ metric value ကိုယူပါတယ္။
metric-type (optional): OSPF external route types (OE1 အတြက္ 1 or OE2 အတြက္ 2) ကိုေရြးခ်ယ္ေပးရပါတယ္။ မေရြးပါက default အားျဖင့္ 2 ဟုသတ္မွတ္ပါတယ္။
route-map (optional): route filtering အတြက္အသံုးျပဳပါတယ္။
subnets (optional): အဲဒီ keyword မပါရင္ classful network ေတြကိုသာ redistribute လုပ္ပါတယ္။

Default metric for OSPF redistribution
1. BGP ကလာရင္ 1
2. Other OSPF process ကလာရင္ source route's metric နွင့္တူသည္။
3. all other sources (eg. eigrp) ကလာရင္ 20.

ဆက္ရန္..........
19/4/2011

OSPF - Part 4

OSPF Costs
Default costs
1.1785 on 56kbps serial link
2.64 on T1 (1.544Mbps serial link)
3.10 on Ethernet
4.1 on Fast Ethernet
5.1 on Gigabit Ethernet

Calculation
Cost = 100Mbps/bandwidth, where 100Mbps is default reference bandwidth

Command syntax:
router(config-if)# ip ospf cost value(0~65535)
OR
router(config-if)# ospf auto-cost reference-bandwidth value(1~4,294,967)

100Mbps သည္ default reference bandwidth ျဖစ္ကာ ၄င္းအားတိုးျမင့္ျခင္းျဖင့္ (eg. 1000Mbps) network performance ကို ျမင့္တင္နိုင္သည္။ ဥပမာ… default အားျဖင့္ Gigabit Ethernet cost ကို 1 (Fast Ethernet နွင့္တူသည္) ဟုထားေသာေၾကာင့္ ထိေရာက္ေသာ network performance ကိုမရရွိနုိင္ပါ… reference bandwidth ကိုတိုးျမင့္ျခင္းျဖင့္ ေျဖရွင္းရသည္။

Example: ref: http://ccietobe.blogspot.com/

R1#show ip route | begin Gateway
Gateway of last resort is not set
1.0.0.0 /32 is subnetted, 2 subnets
C 1.1.1.1 is directly connected, Loopback0
C 1.1.1.2 is directly connected, Loopback1
2.0.0.0 /32 is subnetted, 1 subnets
O 2.2.2.2 [110/65] via 172.12.12.2, 00:08:50, Serial1/0
4.0.0.0 /32 is subnetted, 1 subnets
O IA 4.4.4.4 [110/129] via 172.12.12.2, 00:08:50, Serial1/0
172.12.0.0 /24 is subnetted, 2 subnets
C 172.12.12.0 is directly connected, Serial1/0
O IA 172.12.23.0 [110/128] via 172.12.12.2, 00:08:50, Serial1/0

R1#show ip ospf int s1/0 | inc Cost
Process ID 1, Router ID 1.1.1.1, Network Type POINT_TO_POINT, Cost: 64

Chaging the reference-bandwidth:

R1(config)#router ospf 1
R1(config-router)#auto-cost reference-bandwidth 1000
% OSPF: Reference bandwidth is changed.

R1#show ip ospf int s1/0 | inc Cost
Process ID 1, Router ID 1.1.1.1, Network Type POINT_TO_POINT, Cost: 647

Calculations:

100000000/1544000 = 64
1000000000/1544000 = 647

R1#show ip route | begin Gateway
Gateway of last resort is not set
1.0.0.0 /32 is subnetted, 2 subnets
C 1.1.1.1 is directly connected, Loopback0
C 1.1.1.2 is directly connected, Loopback1
2.0.0.0 /32 is subnetted, 1 subnets
O 2.2.2.2 [110/648] via 172.12.12.2, 00:01:30, Serial1/0
4.0.0.0 /32 is subnetted, 1 subnets
O IA 4.4.4.4 [110/712] via 172.12.12.2, 00:01:30, Serial1/0
172.12.0.0 /24 is subnetted, 2 subnets
C 172.12.12.0 is directly connected, Serial1/0
O IA 172.12.23.0 [110/711] via 172.12.12.2, 00:01:30, Serial1/0

19/4/2011

5 Fast-ways to boost your energy

1. Eating a high-fiber cereal: Body digests fiber more slowly, which can provide a longer-lasting energy supply during the day.
2. Laying off the caffeine: Caffeine provides that quick pick-me-up by stimulating the central nervous system. But more than 200 or 300 mg (two to three cups) a day can work against you by causing jitteriness, digestive problems, and headaches. And consuming caffeine too late in the day can prevent a good night’s sleep.
3. Drinking more water: According to research at Tufts University, even mild dehydration reduces concentration and brings down your mood. It also drains energy.
4. Going for a walk outside: California State University scientists found that a brisk 10-minute walk increases your energy  level and sustains it for two hours. Recent studies show that spending 20 minutes a day outdoors can significantly increase vitality.
5. Munching on pumpkin seeds: They contain a lot of magnesium, and research shows that too little of the mineral can sap your energy. Almonds, cashews, halibut, spinach, and soybeans are other good sources of magnesium.

ref: Reader Digest
10/4/2011

Network Protocol Handbook

Note***: It's second edition not a final one.
Download here for fourth edition (.chm format).
8/4/2011

OSPF - Part 3

Default route in OSPF

Command Syntax: default-information originate [always][metric value][metric-type type-value][route-map name]
ဒီcommand ကိုသံုးရင္ default အားျဖင္႔ default route ကို OSPF area အတြင္းသို႔ LSA Type5 (OE2) ျဖင့္ flood လုပ္သည္။ Default route ၁ခု routing table ထဲတြင္ရွိရန္လိုသည္… သို႔မဟုတ္ command တြင္ always ကိုထည့္ေပးရသည္။ Default metric value မွာ 1 ျဖစ္ၿပီး ငယ္တဲ့ metric ရွိေသာ route ကိုသာ သံုးျပဳသည္။ OE1, OE2 option အတြက္ metric-type 1 or 2 ဟူ၍  ညွိယူရသည္။ When to advertise (or) when to withdraw default route permission အတြက္ route-map ကိုအသံုးျပဳသည္။

Virtual Link

OSPF Area အားလံုးသည္ Area0 နွင့္ခ်ိတ္ဆက္ရမည္ဟူေသာ concept အရ ပံုတြင္ျပထားသည့္အတိုင္း Area2 သည္ Area0 နွင့္ တိုက္ရိုက္မခ်ိတ္ဆက္နုိင္ပါက Virtual-link ကိုအသံုးျပဳနုိင္သည္။ ABR (R1 and R2) မ်ားသည္ virtual-link ေပၚတြင္ unicast packet ျဖင့္ဆက္သြယ္ၾကသည္။ Virtual-link ေပၚတြင္ LSA မ်ား periodic re-flooding မျဖစ္ေစရန္ router မ်ားသည္ LSA packet မ်ားထဲတြင္ Do-Not-Age (DNA) bit ကို ON ရသည္။ အေရးႀကီးဆံုးမွာ Transit Area (Area1) သည္ Stub area မျဖစ္ရပါ။
Example configuration:
R1(config)# router ospf 1
R1(config)# area 1 virtual-link 4.4.4.4

R2(config)# router ospf 1
R2(config)# area 1 virtual-link 1.1.1.1

Virtual-link command တြင္အသံုးျပဳထားေသာ RID မ်ားကို ping ၍မရနိုင္ပါ။

OSPF Authentication
SimpleRouter(config)# router ospf 3
        # area 0 authentication
        # int fa0/0
        # ip ospf authentication
        # ip ospf authentication-key HELLO
MD5Router(config)# router ospf 3
        # area 0 authentication message-digest
        # int fa0/0
        # ip ospf authentication message-digest
        # ip ospf message-digest-key 1 md5 HELLO
၄င္းcommand နွစ္ေၾကာင္းသံုးလ်ွင္ Area ၁ခုလံုး Authentication သံုးရမည္။

Authentication on Virtual-link (using previous figure)
Simple
Router(config)# router ospf 1
        # area 1 virtual-link 4.4.4.4 authentication authentication-key HELLO
MD5
Router(config)# router ospf 1
        # area 1 virtual-link 4.4.4.4 authentication message-digest-key 1 md5 HELLO

5/4/2011

Official UBUNTU Server Book

passwd: helloworld

30/3/2011

OSPF - Part 2

Router ID (RID)
OSPF network မွာရွိေသာ router တစ္လံုးခ်င္းဆီတြင္ unique router ID ရွိၾကသည္။ ပံုမွန္အားျဖင့္ loopback address ကို RID အျဖစ္သတ္မွတ္ၿပီး loopback မရွိက active ျဖစ္ေနေသာ အႀကီးဆံုး address ပိုင္ဆိုင္ထားသည့္ interface ကို RID ဟုသတ္မွတ္ပါသည္။ RID ကို manually လည္းသတ္မွတ္ နုိင္ပါသည္။ router-id command > loopback > interface address ဟုမွတ္ထားနုိင္သည္။

DR and BDR routers
DR ေခၚ Designated Router သည္ OSPF group ၁ခုအတြင္း priority (သို႔) RID အျမင့္ဆံုးျဖစ္သည္။ Broadcast traffic (route information, updates) မ်ားကို DR မွသာ လႊတ္သည္။ DR ေရြးခ်ယ္ရာတြင္ ပထမအဆင့္အေနျဖင့္ priority ခ်င္းယွဥ္ၿပီး ပိုျမင့္ေသာ router က DR ျဖစ္လာသည္။ အကယ္၍ priority တူေနပါက RID အျမင့္ဆံုးကို ေရြးခ်ယ္သည္။ priority > RID ဟုမွတ္ထားနုိင္သည္။

OSPF Router Types
• Backbone Router (BR): 1, 2, 3
• Area Border Router (ABR): 3
• Autonomous System Boundary Router (ASBR): 6

LSA Packet Types (နဲနဲေလးေတာ့ရွဳပ္မယ္)
• Type1 (Router LSA): OSPF run ထားတဲ့ router တိုင္း generate လုပ္ၿပီး Area 1ခု အတြင္းမွာပဲသြားသည္။
• Type2 (Network LSA): DR ကပဲ generate လုပ္ၿပီး Area 1ခု အတြင္းတြင္သာသြားသည္။
• Type3 (Internal Summary LSA): ABR မွ generate လုပ္ၿပီး ကပ္ရပ္ OSPF area ၏ information (summary route) ကို Backbone router မ်ားဆီ သို႔ပို႔သည္။
• Type4 (External Summary LSA): ABR မွ generate လုပ္ၿပီး ASBR ဆီသို႔ ေရာက္နုိင္မည့္ route ကိုေဖာ္ျပသည္။ Backbone router မ်ားဆီ သို႔ပို႔သည္။
• Type5 (AS LSA): ASBR ကသာ ၄င္း LSA ကို generate လုပ္ၿပီး AS မတူတဲ့ external network information (eg. EIGRP) ကို internal router ေတြဆီ သို႔ပို႔သည္။ LSA Type5 ကို External Type1 (OE1) နွင့္ Type2 (OE2) ဟူ၍ 2မ်ိဳးထပ္ခြဲသည္။
• Type6 (Multicast LSA): a Cisco router will ignore this type and generate syslog entry if it receives one.
• Type7 (NSSA LSA): NSSA area မွ ASBR က generate လုပ္ၿပီး external network information ကို ABR ဆီသို႔ပို႔သည္။ ABR က Type5 LSA ျဖင့္အျခား area ဆီသို႔ redistribute ျပန္လုပ္ေပးသည္။ Type5 ကဲ့သို႔ External Type1 (ON1) နွင့္ Type2 (ON2) ဟူ၍ 2မ်ိဳးထပ္ခြဲသည္။
ဂေလာက္သိရင္ OK ၿပီ…..


OSPF Area Types
• Backbone Area: Area0
• Stubby Area: Default route နွင့္ summary route ကိုသာ လက္ခံၿပီး external routes ေတြကို လက္မခံပါ။ Allow Type2, 3, 4 LSAs and Block Type5 LSA. Area0 ကို stub area လုပ္ျခင္း သည္းခံပါ…
• Totally Stubby Area: Default route သာ လက္ခံသည္။ Allow Type2 and Block Type3, 4, 5 LSAs…
• Not-So-Stubby (NSSA) Area: ပံုမွန္ stubby area နွင့္တူၿပီး ၄င္း areaတြင္ ASBR (အျခား AS မွ external route မ်ားလက္ခံရန္) ရွိေသာေၾကာင့္ Type7 LSA ကိုပါလက္ခံသည္။
• Totally NSSA Area: ပံုမွန္ NSSA area နွင့္တူၿပီး ၄င္း areaတြင္ ASBR ရွိေသာေၾကာင့္ Type7 LSA ကိုပါလက္ခံသည္။

Stub Type	Allow LSA Types	Block LSA Types	Default route
Stubby	1, 2, 3, 4	5	Yes
Totally Stubby	1, 2	3, 4, 5	Yes
NSSA	1, 2, 3, 4, 7	5	Yes
Totally NSSA	1, 2, 7	3, 4, 5	Yes

Note***: Totally Stubby နွင့္ Totally NSSA တို႔သည္ Cisco Proprietary မ်ားျဖစ္ၾကသည္။

 

Fig: Ref: http://www.ccnpguide.com

 Fig: Ref: http://www.netcontractor.pl

1/4/2011

OSPF - Part 1

OSPF (Open Shortest Path First)
Cisco စာအုပ္မွ OSPF အေၾကာင္း ဖတ္ထားသမ်ွ သိသေလာက္ ရွဲပါမည္။  (လိုတာကူျဖည့္ေပးပါရန္။)

OSPF Features
1. Areas မ်ားနွင့္ အလုပ္လုပ္သည္။
2. Routing update traffic မ်ားေလ်ွာ့ခ်နုိင္သည္။
3. VLSM support လုပ္သည္။
4. Router အေရအတြက္ သည္ unlimited ျဖစ္သည္။ သို႔ေသာ္ Area တစ္ခုအတြင္း အမ်ားဆံုး 50 routers သာထားသင့္သည္။
5. Open standard ျဖစ္သည္။
6. Default အားျဖင့္ auto summarization ပိတ္ထားသည္။

Neighbor and adjacencies
Broadcast link ေတြမွာ neighbors ေတြဆီသို႔ Hello packet မ်ားကို 224.0.0.5 multicast address ျဖင့္ 10 seconds တစ္ခါပို႔ၿပီး Non-broadcast link ေတြမွာ 30 seconds တစ္ခါပို႔သည္။ Route changes ျဖစ္လ်ွင္ DR ဆီသို႔ changes ရွိေသာ routerက 224.0.0.6 multicast address ျဖင့္ changes ကိုပို႔ၿပီး DR မွ၄င္း changes ကိုက်န္ routers မ်ားထံ 224.0.0.5 ျဖင့္ျပန္ပို႔သည္။ OSPF packet type အားလံုးကို IP protocol 89 ျဖင့္ encapsulation လုပ္သည္။

Possible states of neighbor relationship
1. Down
2. Init: neighbor router မွ hello packet စတင္ရရွိခ်ိန္။
3. 2-way: neighbor နွင့္ bi-directional communication link တည္ေဆာက္ၿပီးခ်ိန္။
4. Exstart: DR/BDR election လုပ္ၿပီး link state info: sequence ေတြဖလွယ္္ၿပီးခ်ိန္။ (only DR & BDR)
5. Exchange: Database Descriptor (DBD) packet (DDP ဟုလည္း ေခၚသည္) exchange လုပ္ေသာအခ်ိန္။
6. Loading: လိုအပ္ေသာ route မ်ားအတြက္ link state info: ေတြဖလွယ္ခ်ိန္။
7. Full: Fully adjacent state
8. Attempt: manually configure လုပ္ထားတဲ့ NBMA network မွာေတြ႔ရွိနုိင္သည္။ Dead interval ကုန္၍ Hello packet မရလ်ွင္ unicast packet ပို႔ေသာအခ်ိန္လည္းျဖစ္သည္။

OSPF Packet Types
1. Hello
2. DBD: router ID lists + sequence number
3. Link state request (LSR): လိုအပ္ေသာ link-state info: request လုပ္ရန္ DBD packetအေနာက္ကသြားသည္။
4. LSU: LSR ကို reply လုပ္ေသာ packet (containing request info:)
5. LSAck: LS info: ေတြရရွိၾကာင္း acknowledge ျပန္ေသာ packet

OSPF packet header format + Data

Version: OSPF version (2 or 3)
Type: packet type 5ခုထဲမွ တခုခု ျဖစ္ေၾကာင္း ေဖာ္ျပသည္။
Authentication Type: no authentication (or) plain-text (or) MD5
Authentication Data
Data: packet type 5ခုေပၚမူတည္ၿပီး data ကြဲျပားသည္။

1/4/2011