8/14/2019 Description: Protocol Suite: TCP/IP. Type: Transport Layer

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Description:

Protocol suite: TCP/IP.

Type: Transport layer interior link state routing protocol.

Multicast addresses: 224.0.0.5 (all routers), 224.0.0.6 (designated routers).

IPProtocol: 89.SNMPMIBs: iso.org.dod.internet.mgmt.mib-2.ospf (1.3.6.1.2.1.14)

Working groups: ospf, Open Shortest Path First IGP.

Links: OSPF authentication codes.

OSPF Opaque types.

OSPF signature algorithms.

OSPF Traffic Engineering TLVs.

MAC header IP header OSPF header Data:::

OSPF header:

00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 2

Version Type Length

Router ID

Area ID

Checksum AuType

Authentication:::

Data :::

Version. 8 bits.OSPF version number.

Type. 8 bits.OSPF request/reply code.

Type Description References

1 Hello. RFC 2328,RFC 2740

2 Database description. RFC 2328,RFC 2740

3 Link state request. RFC 2328,RFC 2740

4 Link state update. RFC 2328,RFC 2740

5 Link state acknowledgment. RFC 2328,RFC 2740

Length. 16 bits.

Size of the OSPF message including the OSPF header in bytes.

http://www.networksorcery.com/enp/topic/ipsuite.htmhttp://www.networksorcery.com/enp/protocol/ip/multicast.htmhttp://www.networksorcery.com/enp/protocol/ip.htmhttp://www.networksorcery.com/enp/protocol/snmp.htmhttp://www.networksorcery.com/enp/protocol/snmp/mibs.htmhttp://www.networksorcery.com/enp/protocol/snmp/mibs.htmhttp://www.ietf.org/html.charters/wg-dir.htmlhttp://www.ietf.org/html.charters/ospf-charter.htmlhttp://www.iana.org/assignments/ospf-authentication-codeshttp://www.iana.org/assignments/ospf-opaque-typeshttp://www.iana.org/assignments/ospf-opaque-typeshttp://www.iana.org/assignments/ospf-sig-alghttp://www.iana.org/assignments/ospf-traffic-eng-tlvshttp://www.networksorcery.com/enp/protocol/ip.htmhttp://www.networksorcery.com/enp/protocol/ospf.htm#Data%23Datahttp://www.networksorcery.com/enp/protocol/ospf.htm#Data%23Datahttp://www.networksorcery.com/enp/protocol/ospf.htm#Version%23Versionhttp://www.networksorcery.com/enp/protocol/ospf.htm#Type%23Typehttp://www.networksorcery.com/enp/protocol/ospf.htm#Length%23Lengthhttp://www.networksorcery.com/enp/protocol/ospf.htm#Router%20ID%23Router%20IDhttp://www.networksorcery.com/enp/protocol/ospf.htm#Area%20ID%23Area%20IDhttp://www.networksorcery.com/enp/protocol/ospf.htm#Checksum%23Checksumhttp://www.networksorcery.com/enp/protocol/ospf.htm#AuType%23AuTypehttp://www.networksorcery.com/enp/protocol/ospf.htm#Authentication%23Authenticationhttp://www.networksorcery.com/enp/protocol/ospf.htm#Data%23Datahttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2740.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2740.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2740.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2740.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2740.txthttp://www.networksorcery.com/enp/topic/ipsuite.htmhttp://www.networksorcery.com/enp/protocol/ip/multicast.htmhttp://www.networksorcery.com/enp/protocol/ip.htmhttp://www.networksorcery.com/enp/protocol/snmp.htmhttp://www.networksorcery.com/enp/protocol/snmp/mibs.htmhttp://www.ietf.org/html.charters/wg-dir.htmlhttp://www.ietf.org/html.charters/ospf-charter.htmlhttp://www.iana.org/assignments/ospf-authentication-codeshttp://www.iana.org/assignments/ospf-opaque-typeshttp://www.iana.org/assignments/ospf-sig-alghttp://www.iana.org/assignments/ospf-traffic-eng-tlvshttp://www.networksorcery.com/enp/protocol/ip.htmhttp://www.networksorcery.com/enp/protocol/ospf.htm#Data%23Datahttp://www.networksorcery.com/enp/protocol/ospf.htm#Version%23Versionhttp://www.networksorcery.com/enp/protocol/ospf.htm#Type%23Typehttp://www.networksorcery.com/enp/protocol/ospf.htm#Length%23Lengthhttp://www.networksorcery.com/enp/protocol/ospf.htm#Router%20ID%23Router%20IDhttp://www.networksorcery.com/enp/protocol/ospf.htm#Area%20ID%23Area%20IDhttp://www.networksorcery.com/enp/protocol/ospf.htm#Checksum%23Checksumhttp://www.networksorcery.com/enp/protocol/ospf.htm#AuType%23AuTypehttp://www.networksorcery.com/enp/protocol/ospf.htm#Authentication%23Authenticationhttp://www.networksorcery.com/enp/protocol/ospf.htm#Data%23Datahttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2740.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2740.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2740.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2740.txthttp://www.networksorcery.com/enp/rfc/rfc2328.txthttp://www.networksorcery.com/enp/rfc/rfc2740.txt

8/14/2019 Description: Protocol Suite: TCP/IP. Type: Transport Layer

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Router ID. 32 bits.

The Router ID of the packet's source.

Area ID. 32 bits.The area that this packet belongs to. All OSPF packets are associated with a single area.

Most travel a single hop only. Packets travelling over a virtual link are labelled with thebackbone Area ID of 0.0.0.0.

Checksum. 16 bits.The standard IP checksum of the entire contents of the packet, starting with the OSPF

packet header but excluding the 64 bit authentication field. This checksum is calculated

as the 16-bit one's complement of the one's complement sum of all the 16 bit words in the

packet, excepting the authentication field. If the packet's length is not an integral numberof 16 bit words, the packet is padded with a byte of zero before checksumming. The

checksum is considered to be part of the packet authentication procedure; for some

authentication types the checksum calculation is omitted.

AuType. 16 bits.

Identifies the authentication procedure to be used for the packet.

Authentication. 64 bits.

Authentication Description References

0 None. RFC 2328

1 Simple password authentication. RFC 2328

2 Cryptographic authentication. RFC 2328

3-

65535

Reserved.

Data. Variable length.

OSPF version 3 header:

This version is designed to support OSPF over IPv6 links.

00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 2Version Type Length

Router ID

Area ID

Checksum Instance ID Reserved

Data :::

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8/14/2019 Description: Protocol Suite: TCP/IP. Type: Transport Layer

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Version. 8 bits. Always set to 3.

OSPF version number.

Checksum. 16 bits.OSPF uses the standard checksum calculation for IPv6 applications: The 16-bit one's

complement of the one's complement sum of the entire contents of the packet, startingwith the OSPF packet header, and prepending a "pseudo-header" of IPv6 header fields.

The "Upper-Layer Packet Length" in the pseudo-header is set to value of the OSPFpacket header's length field. The Next Header value used in the pseudo-header is 89. If

the length of the packet is not an integral number of 16-bit words, the packet is padded

with a byte of zero before checksumming. Before computing the checksum, thechecksum field in the OSPF packet header is set to 0.

Instance ID. 8 bits.

Enables multiple instances of OSPF to be run over a single link. Each protocol instance

would be assigned a separate Instance ID; the Instance ID has local link significance

only. Received packets whose Instance ID is not equal to the receiving interface'sInstance ID are discarded.

reserved. 8 bits.

Must be cleared to 0.

Glossary:

ABR, Area Border Router.

NSSA, "not-so-stubby" area.(RFC 1587) NSSAs are similar to the existing OSPF stub area configuration option but

have the additional capability of importing AS external routes in a limited fashion.