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ME60 V800R010C10SPC500 Feature Description - WAN Access 01

This is ME60 V800R010C10SPC500 Feature Description - WAN Access
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Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
OSPFv3 LSA Format

OSPFv3 LSA Format

Each ME device in an autonomous system (AS) generates one or more types of link state advertisements (LSAs), depending on the ME device's type. Multiple LSAs form a link state database (LSDB). Open Shortest Path First (OSPF) for IPv6 encapsulates routing information into LSAs for transmission. Commonly used LSAs include:

LSA Header Format

All LSAs have the same header. Figure 7-26 shows an LSA header.

Figure 7-26 LSA header
Table 7-18 describes LSA header fields.
Table 7-18 LSA header fields

Field

Length

Description

LS age

16 bits

Time that elapses after the LSA is generated, in seconds. The value of this field continually increases regardless of whether the LSA is transmitted over a link or saved in an LSDB.

LS type

16 bits

Type of the LSA. The values are as follows:

  • Type 1: Router-LSA.

  • Type 2: Network-LSA.

  • Type 3: Inter-Area-Prefix-LSA.

  • Type 4: Inter-Area-Router-LSA.

  • Type 5: AS-external-LSA.

  • Type 7: NSSA-LSA.

  • Type 8: Link-LSA.

  • Type 9: Intra-Area-Prefix-LSA.

Link State ID

32 bits

This field together with the LS type field describes an LSA in an AS.

Advertising Router

32 bits

Router ID of the ME device that generates the LSA.

LS sequence number

32 bits

Sequence number of the LSA. Neighbors can use this field to identify the latest LSA.

LS checksum

16 bits

Checksum of all fields except the LS age field.

Length

16 bits

Length of the LSA including the LSA header, in bytes.

Router-LSA

A router-LSA describes the link status and cost of a ME device. Router-LSAs are generated by a ME device and advertised within the area to which the ME device belongs. Figure 7-27 shows the format of a router-LSA.

Figure 7-27 Format of a router-LSA
Table 7-19 describes router-LSA fields.
Table 7-19 Router-LSA fields

Field

Length

Description

Nt (NSSA translation)

1 bit

If the ME device that generates the LSA is an NSSA border router, this field is set to 1. In other cases, this field is set to 0. When this field is set to 1, the router is unconditionally translating NSSA-LSAs into AS-external-LSAs.

x

1 bit

This field is deprecated.

V (Virtual Link)

1 bit

If the ME device that generates the LSA is located at one end of a virtual link, this field is set to 1. In other cases, this field is set to 0.

E (External)

1 bit

If the ME device that generates the LSA is an autonomous system boundary router (ASBR), this field is set to 1. In other cases, this field is set to 0.

B (Border)

1 bit

If the ME device that generates the LSA is an area border router (ABR), this field is set to 1. In other cases, this field is set to 0.

Options

24 bits

The optional capabilities supported by the ME device.

Type

8 bits

Type of the ME device link. The values are as follows:

  • 1: The ME device is connected to another ME device in point-to-point (P2P) mode.

  • 2: The ME device is connected to a transport network.

  • 3: Reserved.

  • 4: The ME device is connected to another ME device over a virtual link.

metric

16 bits

Cost of the link.

Interface ID

32 bits

The Interface ID assigned to the interface.

Neighbor Interface ID

32 bits

The Interface ID the neighbor ME device has associated with the link.

  • For transit links, the value is the interface ID of the DR.
  • For links of other types, the value is the interface ID of the neighboring device.

Neighbor Router ID

32 bits

The Router ID of the neighbor ME device.

  • For transit links, the value is the router ID of the DR.
  • For links of other types, the value is the router ID of the neighboring device.

Network-LSA

A network-LSA describes the link status of all ME devices on the local network segment. Network-LSAs are generated by a DR on a broadcast or non-broadcast multiple access (NBMA) network and advertised within the area to which the DR belongs. Figure 7-28 shows the format of a network-LSA.

Figure 7-28 Format of a network-LSA
Table 7-20 describes network-LSA fields.
Table 7-20 Network-LSA fields

Field

Length

Description

Options

24 bits

The optional capabilities supported by the ME device.

Attached Router

32 bits

Router IDs of all ME devices on the broadcast or NBMA network, including the router ID of the DR

Inter-Area-Prefix-LSA

An inter-area-prefix-LSA describes routes on a network segment in an area. It is generated by the ABR. The routes are advertised to other areas.

Figure 7-29 shows the format of an inter-area-prefix-LSA.

Figure 7-29 Format of An inter-area-prefix-LSA
Table 7-21 describes inter-area-prefix-LSA fields.
Table 7-21 Network-summary-LSA fields

Field

Length

Description

PrefixLength

8 bits

Length of the prefix.

PrefixOption

8 bits

The capabilities associated with the prefix.

Address Prefix

32 bits

An encoding of the prefix itself.

Inter-Area-Router-LSA

An inter-area-router-LSA describes routes to the ASBR in other areas. It is generated by the ABR. The routes are advertised to all related areas except the area that the ASBR belongs to.

Figure 7-30 shows the format of an inter-area-prefix-LSA.

Figure 7-30 Format of an inter-area-router-LSA

Table 7-22 describes inter-area-router-LSA fields.

Table 7-22 Inter-area-router-LSA fields

Field

Length

Description

Destination Router ID

32 bits

The Router ID of the router being described by the LSA.

AS-External-LSAs

An as-external-LSA describes destinations outside the AS, it is originated by ASBR.

Figure 7-31 shows the format of an as-external-LSA.

Figure 7-31 Format of an as-external-LSA

Table 7-23 describes as-external-LSA fields.

Table 7-23 As-external-LSA fields

Field

Length

Description

E

1 bit

The type of external metric.
  • If this field is 1, the specified metric is a Type 2 external metric.
  • If this field is 0, the specified metric is a Type 1 external metric.

F

1 bit

Whether a Forwarding Address has been included in the LSA.
  • If this field is 1, a Forwarding Address has been included in the LSA.
  • If this field is 0, no Forwarding Address is included in the LSA.

T

1 bit

Whether an External Route Tag has been included in the LSA.
  • If this field is 1, an External Route Tag has been included in the LSA.
  • If this field is 0, no External Route Tag is included in the LSA.

Referenced LS Type

16 bits

Indicates the referenced LS type. If non-zero, an LSA with this LS type is to be associated with this LSA (see Referenced Link State ID below).

Forwarding Address

128 bits

A fully qualified global IPv6 address.

External Route Tag

32 bits

Indicates the external route tag, which can be used to communicate additional information between ASBRs.

Referenced Link State ID

32 bits

Indicates the referenced link state ID.

NSSA-LSAs

An NSSA-LSA describes destinations outside the AS, it is originated by ASBR.

Figure 7-32 shows the format of an NSSA-LSA.

Figure 7-32 Format of an NSSA-LSA

Link-LSAs

Each ME device generates a link LSA for each link. A link LSA describes the link-local address and IPv6 address prefix associated with the link and the link option set in the network LSA. It is transmitted only on the link.

Figure 7-33 shows the format of a Link-LSA.

Figure 7-33 Format of a Link-LSA

Table 7-24 describes link-LSA fields.

Table 7-24 Link-LSA fields

Field

Length

Description

Rtr Priority

8 bits

The Router Priority of the interface.

Options

24 bits

The set of Options bits that the ME device would like set in the network-LSA that will be originated by the DR on broadcast or NBMA links.

Link-local Interface Address

128 bits

The originating ME device's link-local interface address on the link.

Number of prefixes

32 bits

The number of IPv6 address prefixes contained in the LSA.

Intra-Area-Prefix-LSAs

Each ME device or DR generates one or more intra-area prefix LSAs and transmits it in the local area.
  • An LSA generated on a router describes the IPv6 address prefix associated with the router LSA.
  • An LSA generated on a DR describes the IPv6 address prefix associated with the network LSA.

Figure 7-34 shows the format of an intra-area-prefix-LSA.

Figure 7-34 Format of an intra-area-prefix-LSA

Table 7-25 describes intra-area-prefix-LSA fields.

Table 7-25 Intra-area-prefix-LSA fields

Field

Length

Description

Referenced LS Type

16 bits

This field identifies the router-LSA or network-LSA with which the IPv6 address prefixes should be associated.
  • If Referenced LS Type is 0x2001, the prefixes are associated with a router-LSA.
  • If Referenced LS Type is 0x2002, the prefixes are associated with a network-LSA.

Referenced Link State ID

32 bits

Indicates the referenced link state ID.
  • If Referenced LS Type is 0x2001, Referenced Link State ID should be 0.
  • If Referenced LS Type is 0x2002, Referenced Link State ID should be the Interface ID of the link's DR.

Referenced Advertising Router

32 bits

Indicates the ID of the referenced advertising ME device.
  • If Referenced LS Type is 0x2001, Referenced Advertising Router should be the originating router's Router ID.
  • If Referenced LS Type is 0x2002, Referenced Advertising Router should be the Designated Router's Router ID.
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Updated: 2019-01-04

Document ID: EDOC1100059473

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