ospf simple application

OSPF （SPF）

A link-state routing protocol, and a public standard,

In theory there is no network size restrictions;

The hierarchical design support network, the network can be divided into two layers.

Layer is to be distinguished by the concept of "region".

- backbone area

- non-backbone area

All non-backbone must be directly connected to the backbone in order to communicate.

Router because of a region and are divided into different types:

- backbone routers

All links are all routers in the backbone area;

- non-backbone router

All links are all non-backbone routers area;

- Area Border Router (*) [ABR: area border router]

It must be connected to the backbone region and a non-backbone areas;

- [autonomous system border router ASBR:]

Router has the ability to import external routes, called the OSPF ASBR.

-working principle

1, set up the neighbor table

Only use hello packets.

OSPF routing, only exchanged between routers OSPF neighbors;

Neighbor state:

down

init

2way

Exstart(exchange start)

exchange

loading

full

2, database synchronization

LSA-link state advertisement, LSA;

3, routing table calculation (for LSA calculated by the SPF algorithm, to obtain the final routing entry)

-OSPF message:

hello:

dbd: database description, database description packets;

lsu: link state update, the link state update packet;

lsr: link state request, link state request packet;

lsack: link state ack, link state acknowledgment packets;

1, configure OSPF

[R1] ospf [process-id] // not write, the default is 1;

[R1-ospf-1] area 0 // 0 entry region;

[R1-ospf-1-area-0.0.0.0] network 192.168.12.1 0.0.0.0

// declare exactly where the link 192.168.12.1

The OSPF 0;

So gi0 / 0/0, then enable OSPF 1:

Ospf packet # 1 can be transmitted;

# 1 may receive a packet ospf;

# The IP address can be in port

Network part, into an OSPF packet 1, the transmission out to the neighboring routers.

2, verification

display ospf [1] peer brief // Check brief OSPF neighbor information table;

display ospf [1] peer // View Details OSPF neighbor table;

display ospf [1] brief // view information on the local device OSPF 1;

display ip routing-table // Check the OSPF routing table of

(Route determining types and attributes)

=================================================================

Factors establish OSPF neighbor:

1, to ensure a minimum range of Ping the links are mutually; (exchange)

R 1: R 2 Ping;

R 2: R 1 Ping;

2, ensure that the port can send packets device;

#network to declare the correct network range;

# Make sure the receiving port OSPF packet can not be "passive port - silent-interface"

(OSPF silent-interface on the device Huawei, neither send nor receive packet)

ospf 1

silent-interface gi0/0/0

3, to ensure that the port device can receive packets;

#network to declare the correct network range;

# Ensure that the ACL is to allow OSPF traffic;

# Make sure the receiving port OSPF packet can not be "passive port - silent-interface"

(OSPF silent-interface on the device Huawei, neither send nor receive packet)

R1:

acl name Deny-OSPF advance

rule 5 deny ospf source 192.168.12.2 0.0.0.0 destination 224.0.0.5 0.0.0.0

interface gi0/0/0

traffic-filter inbound acl name Deny-OSPF

4, the key parameters to ensure consistent OSPF Hello packet; hello parameters [Comparative]

# Router neighbor establish direct relations, RID must not be the same;

[R1] ospf 1 router-id xxxx // use specified RID OSPF 1

<R1> reset ospf 1 process // restart OSPF 1, to take effect;

ID # must be the same region;

[R1]ospf 1

[R1-OSPF-1]area 0

[R1-OSPF-1-area-0.0.0.0]undo network 192.168.12.1 0.0.0.0

[R1-OSPF-1]undo area 0

[R1-OSPF-1]area 1

[R1-OSPF-1-area-1]network 192.168.12.1 0.0.0.0

# Authentication must succeed;

# The subnet mask must have the same (exceptional circumstances)

# Hello time, must be the same;

[R1]interface gi0/0/0

[R1-gi0 / 0/0] changes when the hello, dead ospf timer hello 20 // follow the change, the relationship between the multiple is four times;

# Dead time, it must be the same;

[R1]interface gi0/0/0

[R1-gi0 / 0/0] ospf timer dead time changes dead, hello // 41 unchanged;

# Special flag bit must be exactly the same;

# DR priority, not all 0; (special cases)

[R1]interface gi0/0/0

[R1-gi0/0/0]ospf dr-priority 0

Layer # 3 MTU, exactly the same;

Verify command:

display ospf peer brief // Check OSPF neighbor table

display ospf interface gi0 / 0/0 // View OSPF interface;

Lab topology:

Experimental Procedure:

<Huawei>sys

[Huawei] inter gi 0/0/0

[Huawei-GigabitEthernet0/0/0]undo shutdown

Configuring IP

[Huawei-GigabitEthernet0/0/0]ip address 192.168.12.1 255.255.255.0

[Huawei-GigabitEthernet0/0/0]q

The ospf

[Huawei]ospf

[Huawei-ospf-1]area 0

[Huawei-ospf-1-area-0.0.0.0]network 192.168.12.1 0.0.0.0

[Huawei-ospf-1-area-0.0.0.0]q

[Huawei-ospf-1]q

[Huawei]q

<Huawei>sys

Test whether to ping

[Huawei] ping 192.168.12.2

PING 192.168.12.2: 56 data bytes, press CTRL_C to break

Reply from 192.168.12.2: bytes=56 Sequence=1 ttl=255 time=30 ms

Reply from 192.168.12.2: bytes=56 Sequence=2 ttl=255 time=20 ms

Reply from 192.168.12.2: bytes=56 Sequence=3 ttl=255 time=20 ms

Reply from 192.168.12.2: bytes=56 Sequence=4 ttl=255 time=20 ms

Reply from 192.168.12.2: bytes=56 Sequence=5 ttl=255 time=20 ms

--- 192.168.12.2 ping statistics ---

5 packet(s) transmitted

5 packet(s) received

0.00% packet loss

round-trip min/avg/max = 20/22/30 ms

Check whether to establish adjacency

[Huawei]dis ospf peer

OSPF Process 1 with Router ID 192.168.12.1

Neighbors

Area 0.0.0.0 interface 192.168.12.1(GigabitEthernet0/0/0)'s neighbors

Router ID: 192.168.12.2 Address: 192.168.12.2

State: Full Mode:Nbr is Master Priority: 1

DR: 192.168.12.1 BDR: 192.168.12.2 MTU: 0

Dead timer due in 40 sec

Retrans timer interval: 5

Neighbor is up for 00:00:35

Authentication Sequence: [ 0 ]

Configuring passive port gi0 / 0/0 neither close nor contract

[Huawei]acl name ospf-1 advance

[Huawei-acl-adv-ospf-1]rule 5 deny ospf source 192.168.12.2 0.0.0.0 destination 224.0.0.5 0.0.0.0

[Huawei-acl-adv-ospf-1]q

[Huawei] inter gi 0/0/0

[Huawei-GigabitEthernet0/0/0]traffic-filter inbound acl 3999

[Huawei-GigabitEthernet0/0/0]q

View success

[Huawei]dis ospf

Jan 16 2018 19:32:37-08:00 Huawei %%01OSPF/3/NBR_CHG_DOWN(l)[0]:Neighbor event:n

eighbor state changed to Down. (ProcessId=256, NeighborAddress=2.12.168.192, Nei

ghborEvent=InactivityTimer, NeighborPreviousState=Full, NeighborCurrentState=Dow

Router Configuration 2

<Huawei>sys

[Huawei] inter gi 0/0/0

[Huawei-GigabitEthernet0/0/0]undo shutdown

Configuring IP port

[Huawei-GigabitEthernet0/0/0]ip address 192.168.12.2 255.255.255.0

[Huawei-GigabitEthernet0/0/0]q

The ospf

[Huawei]ospf

[Huawei-ospf-1]area 0

[Huawei-ospf-1-area-0.0.0.0]network 192.168.12.2 0.0.0.0

[Huawei-ospf-1-area-0.0.0.0]q

[Huawei-ospf-1]q

[Huawei]q

result:

ospf simple application

ospf simple application

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