Network Working Group W A Simpson Internet Draft Daydreamer expires in six months September 1994 IPv6 Neighbor Discovery -- ICMP Message Formats draft-simpson-ipv6-discov-formats-00.txt Status of this Memo This document is a submission to the IPng Working Group of the Internet Engineering Task Force (IETF). Comments should be submitted to the ipng@sunroof.eng.sun.com mailing list. Distribution of this memo is unlimited. This document is an Internet-Draft. Internet Drafts are working documents of the Internet Engineering Task Force (IETF), its Areas, and its Working Groups. Note that other groups may also distribute working documents as Internet Drafts. Internet Drafts are draft documents valid for a maximum of six months, and may be updated, replaced, or obsoleted by other documents at any time. It is not appropriate to use Internet Drafts as reference material, or to cite them other than as a ``working draft'' or ``work in progress.'' To learn the current status of any Internet-Draft, please check the ``1id-abstracts.txt'' listing contained in the internet-drafts Shadow Directories on ds.internic.net (US East Coast), nic.nordu.net (Europe), ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim). Abstract This document specifies ICMP messages for the identification and location of adjacent IPv6 nodes. Simpson expires in six months [Page i]
DRAFT IPv6 Discovery Formats September 1994 1. Additional ICMP Packets The Packet format and basic facilities are already defined for ICMP as modified for IPv6 [IPv6-ICMP]. Up-to-date values of the ICMP Type field are specified in the most recent "Assigned Numbers" [RFC-1310]. This document concerns the following values: 33 Solicitation 34 Advertisement 35 Mobile Registration Request 36 Mobile Registration Reply Simpson expires in six months [Page 1]
DRAFT IPv6 Discovery Formats September 1994 1.1. Solicitation +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extensions ... +-+-+-+-+-+-+-+-+-+-+-+- Type 33 Code Up-to-date values are specified in the most recent "Assigned Numbers" [RFC-1310]. Current values are assigned as follows: 0 RESERVED 1 General 2 Router 3 Service Checksum The ICMP Checksum. Extensions This field is variable in length and contains zero or more Extensions. These Extensions are described in a later section. The contents of the Reserved field MUST be zero on transmission, and MUST be ignored on receipt. Future backward-compatible changes to the protocol may specify the contents of the Reserved field or of additional octets at the end of the message. Simpson expires in six months [Page 2]
DRAFT IPv6 Discovery Formats September 1994 1.1.1. General Solicitation The General Solicitation MUST contain at least the following values: IPv6 Header: Destination an IPv6 Address of the target. It MUST NOT contain a multicast address. Source any IPv6 Address associated with the sending node. It MUST NOT contain the Unspecified Address. ICMP fields: Code 1 for General Solicitation. Extensions: Media-Access for interfaces which are not point-to-point links. System-Heard for each Router Advertisement that has been heard, in order of preference. In the unlikely event that not all extensions fit in a single solicitation, as constrained by the MTU of the link, the remaining extensions are removed. Simpson expires in six months [Page 3]
DRAFT IPv6 Discovery Formats September 1994 1.1.2. Router Solicitation The Router Solicitation MUST contain at least the following values: IPv6 Header: Destination the all-routers multicast. The scope is set to intra-link. Source any IPv6 Address associated with the sending node. It MAY contain the Unspecified Address, when the node has not yet determined an IPv6 Address. ICMP fields: Code 2 for Router Solicitation. There are no required extensions. Simpson expires in six months [Page 4]
DRAFT IPv6 Discovery Formats September 1994 1.1.3. Service Solicitation The Service Solicitation MUST contain at least the following values: IPv6 Header: Destination the multicast group associated with the service. The scope is set to intra-site. Source any IPv6 Address associated with the sending node. It MUST NOT contain the Unspecified Address. ICMP fields: Code 3 for Service Solicitation. Extensions: Service-Information One or more qualifiers, in order of importance. In the unlikely event that not all extensions fit in a single solicitation, as constrained by the MTU of the link, the remaining extensions are removed. Simpson expires in six months [Page 5]
DRAFT IPv6 Discovery Formats September 1994 1.2. Advertisement +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | LifeTime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extensions ... +-+-+-+-+-+-+-+-+-+-+-+- Type 34 Code Up-to-date values are specified in the most recent "Assigned Numbers" [RFC-1310]. Current values are assigned as follows: 0 RESERVED 1 General 2 Router 3 Service 4 Local Redirect 5 Remote Redirect Checksum The ICMP Checksum. Sequence Number Contains the number of Advertisement messages sent since the node was initialized. This number MUST include this advertisement. That is, the first Advertisement contains the value one, and the value zero indicates that the number has rolled over. LifeTime Indicates the seconds remaining before the advertised information is considered expired. The maximum time is approximately 18.2 hours. Extensions This field is variable in length and contains zero or more Extensions. These Extensions are described in a later section. Simpson expires in six months [Page 6]
DRAFT IPv6 Discovery Formats September 1994 1.2.1. General Advertisement The General Advertisement MUST contain at least the following values: IPv6 Header: Destination the Source specified in the solicitation. Source the Destination specified in the solicitation. ICMP fields: Code 1 for General Advertisement. Lifetime the interface's configured AdvertisementLifetime. Extensions: Media-Access for interfaces which are not point-to-point links. Other-Identifier for each of that node's known IPv6 Addresses other than the IPv6 Address specified in the IPv6 Source field. The prefix size is set to zero. System-Heard for each Router Advertisement that has been heard, in order of preference. In the unlikely event that not all extensions fit in a single advertisement, as constrained by the MTU of the link, the remaining extensions are removed. Simpson expires in six months [Page 7]
DRAFT IPv6 Discovery Formats September 1994 1.2.2. Router Advertisement The Router Advertisement MUST contain at least the following values: IPv6 Header: Destination the all-nodes multicast. The scope is set to intra-link. Source the primary IPv6 Address of the node. The same IPv6 Address is used for all interfaces. When a router has more than one interface on the same link, or a multi-homed host can hear the same router on more than one link, it is necessary to unambiguously know which router sent this advertisement. The individual routing prefixes for the links are distinguished in the Routing Information extension. ICMP fields: Code 2 for Router Advertisement. Lifetime the interface's configured AdvertisementLifetime. Extensions: Media-Access for interfaces which are not point-to-point links. Routing-Information for each of that interface's associated IPv6 Addresses whose Advertise flags are TRUE. Change-Identifier for each of that interface's recently changed IPv6 Addresses. Other-Identifier for each of that node's other IPv6 Addresses which have not already been included through prefix subsumption. System-Heard for each Router Advertisement that has been heard, in order of preference. In the unlikely event that not all extensions fit in a single advertisement, as constrained by the MTU of the link, multiple advertisements are sent, with each except the last containing as Simpson expires in six months [Page 8]
DRAFT IPv6 Discovery Formats September 1994 many extensions as can fit. Simpson expires in six months [Page 9]
DRAFT IPv6 Discovery Formats September 1994 1.2.3. Service Advertisement The Service Advertisement MUST contain at least the following values: IPv6 Header: Destination the all-nodes multicast. The scope is set by administrative policy. Source any IPv6 Address associated with the sending node. ICMP fields: Code 3 for Service Advertisement. Lifetime the interface's configured AdvertisementLifetime. Extensions: Media-Access for interfaces which are not point-to-point links. Other-Identifier for each of that node's known IPv6 Addresses other than the IPv6 Address specified in the IPv6 Source field. The prefix size is set to zero. Service-Information One or more qualifiers, in order of importance. System-Heard for each Router Advertisement that has been heard, in order of preference. In the unlikely event that not all extensions fit in a single advertisement, as constrained by the MTU of the link, multiple advertisements are sent, with each except the last containing as many extensions as can fit. Simpson expires in six months [Page 10]
DRAFT IPv6 Discovery Formats September 1994 1.2.4. Local Redirect The Local Redirect MUST contain at least the following values: IPv6 Header: Destination the Source specified in the packet being redirected. Source the primary IPv6 Address associated with the sending node. ICMP fields: Code 4 for Local Redirect. Sequence the last Sequence from the target node Advertisement. Lifetime the remaining Lifetime from the target node Advertisement. Extensions: Media-Access for interfaces which are not point-to-point links, the Media-Access extension from the target node Advertisement. Other-Identifier for each IPv6 Address associated with the target node. The metric is set to zero. When the redirect applies to an entire cluster, the prefix size is set to the size of the cluster prefix. Transit-Information one or more, when the redirect is limited to a specific Quality of Service. The metric is set to zero. Redirected-Header The target header. In the unlikely event that not all extensions fit in a single redirect, as constrained by the MTU of the link, the remaining extensions are removed. Only a single redirect is sent. The Local Redirect is used by a router to redirect a host to another router, or to another host on the same link. These uses are Simpson expires in six months [Page 11]
DRAFT IPv6 Discovery Formats September 1994 indistinguishable. Simpson expires in six months [Page 12]
DRAFT IPv6 Discovery Formats September 1994 1.2.5. Remote Redirect The Remote Redirect MUST contain at least the following values: IPv6 Header: Destination the Source specified in the packet being redirected. Source the primary IPv6 Address associated with the sending node. An Authentication Header is required. ICMP fields: Code 5 for Remote Redirect. Sequence the last Sequence from the target node Advertisement. Lifetime the remaining Lifetime from the target node Advertisement. Extensions: Change-Identifier when the IPv6 Destination of the redirected packet is changing. The Prefix Size is set to zero. Other-Identifier for each IPv6 Address associated with the target node. The metric is set to zero, and the prefix size is set to zero. Redirected-Header The target header. In the unlikely event that not all extensions fit in a single redirect, as constrained by the MTU of the link, the remaining extensions are removed. Only a single redirect is sent. The Remote Redirect is primarily used to support Mobility. Simpson expires in six months [Page 13]
DRAFT IPv6 Discovery Formats September 1994 1.3. Mobile Registration Request +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | unused | LifeTime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + Identification + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ Home Agent ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ Care-Of-Address ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extensions ... +-+-+-+-+-+-+-+-+-+-+-+- IPv6 Header: Destination The IPv6 Address of the Agent, when known. When the IPv6 Address is unknown (the agent was discovered via a link-layer protocol), the "all Mobile Agents" multicast address. The link-layer unicast address is used to deliver the datagram to the correct Agent. Source An IPv6 Address belonging to the interface on which this message is sent. A Mobile Node MUST use the transient Care-Of- Address when assigned; otherwise, the Home- Address is used. ICMP fields: Type 35 <TBD> Code Bitmask of optional capabilities: 1 - retain prior registrations 2 - registering through Foreign Agent Simpson expires in six months [Page 14]
DRAFT IPv6 Discovery Formats September 1994 LifeTime The seconds remaining before the registration is considered expired. A value of zero indicates a request for de-registration. A value of all ones indicates infinity. Home Agent The IPv6 Address of a Home Agent. Care-Of-Address The IPv6 Address for the decapsulation end of a tunnel. Identification A sequence number assigned by the Mobile Node. This is used to assist in matching Requests with Replies. A Network Time Protocol [RFC-1305] formatted value is preferred. The low-order 32 bits of the NTP format represent fractional seconds, and those bits which are not available from a time source SHOULD be generated from a good source of randomness. A battery-backed clock is the usual source of this value. In more robust implementations, Global Positioning System or authenticated NTP values MAY be used. The elapsed time since system startup or another such monotonically increasing counter MAY be used, but is considered less secure, as it could repeat each time the machine is restarted, or when a poor source of randomness is used for the low-order bits. See [Eastlake, et alia] for a discussion of sources of randomness. It is possible to use an entirely random "nonce" in this field, or to generate nonces from previous registration exchanges. We have not standardized this procedure because of intellectual property concerns. It is also incompatible with the expected venue of the protocol, and presents difficulties with interoperability and security validation. The value MUST NOT be the same as an immediately preceeding request, and SHOULD NOT repeat during the lifetime of the Mobility Security Association between the Mobile Node and the Home Agent. Extensions: Simpson expires in six months [Page 15]
DRAFT IPv6 Discovery Formats September 1994 Other-Identifier required. Contains the Home-Address of the Mobile Node. The metric is set to zero. Mobile-Home Authentication required. Immediately follows all non- authentication extensions. When forwarded by a Foreign Agent, extensions which are specific to the Foreign Agent are removed. All others are copied without modification. Simpson expires in six months [Page 16]
DRAFT IPv6 Discovery Formats September 1994 1.4. Mobile Registration Reply +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | unused | LifeTime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + Identification + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extensions ... +-+-+-+-+-+-+-+-+-+-+-+- IPv6 Header: The Source and Destination of the Request message are swapped for the Reply message. Note that the Source of the original Mobile Registration Request must be saved in order for a Foreign Agent to return the reply to the correct Mobile Node. ICMP fields: Type 36 <TBD> Code One of the following codes: 0 service will be provided. denied by Foreign Agent, 16 reason unspecified. 17 administratively prohibited. 18 insufficient resources. 19 Mobile Node failed authentication. 20 Home Agent failed authentication. 21 Request LifeTime too long. denied by Home Agent, 32 reason unspecified. 33 administratively prohibited. 34 insufficient resources. 35 Mobile Node failed authentication. 36 Foreign Agent failed authentication. Up-to-date values of the Code field are specified in the most recent "Assigned Numbers" [RFC-1310]. Simpson expires in six months [Page 17]
DRAFT IPv6 Discovery Formats September 1994 LifeTime The seconds remaining before the registration is considered expired. A value of zero confirms a request for de-registration. A value of all ones indicates infinity. Identification Copied from the Request message. Extensions: Other-Identifier required. Contains the Home-Address of the Mobile Node. The metric is set to zero. Mobile-Home Authentication required. Immediately follows all non- authentication extensions. Note that the Care-Of-Address and Home Agent are not present in the message. This provides a separate calculation value for mutual authentication. When forwarded by a Foreign Agent, extensions which are specific to the Foreign Agent are removed. All others are copied without modification. Simpson expires in six months [Page 18]
DRAFT IPv6 Discovery Formats September 1994 2. Extensions Extensions allow variable amounts of information to be carried within each Solicitation or Advertisement packet. Some extensions are common to both packet types. The end of the list of Extensions is indicated by the Payload Length of the IPv6 packet. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- | Extension | Length | Data ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- Extension This document concerns the following values: 0 Single Pad (no length field) 1 Multiple Pads (with length field) 2 Change-Identifier 3 Other-Identifier 4 System-Heard 5 Routing-Information 6 Service-Information 7 Transit-Information 8 Redirected-Header 14 Maximum-Receive-Unit 15 Media-Access 16 Mobility (obsolete) 17 Home-Address (obsolete) 32 Mobile-Home Authentication 64 Minimal Encapsulation 65 GRE Encapsulation Up-to-date values are specified in the most recent "Assigned Numbers" [RFC-1310]. Length Indicates the length of the Data field which has been used. The Length does not include the Extension and Length octets. The Single Pad (extension 0) is a special case, which has no Length field. Data This field is zero or more octets and contains the value(s) for this Extension. The format and length of the Data field is determined by the Extension and Length fields. When an extension is encountered which is not recognized, it is Simpson expires in six months [Page 19]
DRAFT IPv6 Discovery Formats September 1994 ignored. The length field is used to skip the data field in searching for the next extension. Every extension is aligned such that internal fields fall on natural boundaries, except that fields larger than 64-bits need only be aligned to 64-bit boundaries. Any unused portion of the datagram between such Extensions is padded as appropriate. The final Extension in a datagram does not require trailing padding. 2.1. Single Pad +-+-+-+-+-+-+-+-+ | Extension | +-+-+-+-+-+-+-+-+ Extension 0 2.2. Multiple Pads +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- | Extension | Length | Data ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- Extension 1 Length Indicates the length of the Data field. Data This field is zero or more bytes of zeroes. Simpson expires in six months [Page 20]
DRAFT IPv6 Discovery Formats September 1994 2.3. Change-Identifier +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension | Length | unused | Prefix Size | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | unused | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ Old IPv6 Address ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ New IPv6 Address ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Extension 2 Length 22 Prefix Size Indicates the number of bits in both IPv6 Addresses which define the cluster prefix width for the link. The value ranges from 0 to 126. Old IPv6 Address Depending on the Prefix Size, it may indicate a cluster, or a single IPv6 Address. New IPv6 Address Depending on the Prefix Size, it may indicate a cluster, or a single IPv6 Address. For advertisements, this allows changing a prefix for every node on a router's interface. For redirects, this allows changing a single target IPv6 Address. Simpson expires in six months [Page 21]
DRAFT IPv6 Discovery Formats September 1994 2.4. Other-Identifier +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension | Length | | Prefix Size | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metric | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ IPv6 Address ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Extension 3 Length 14 Prefix Size Indicates the number of bits in the IPv6 Address which define the cluster prefix width for the link. The value ranges from 0 to 126. If the IPv6 Address does not indicate a valid prefix, the value is zero. Non-routers MUST set this field to zero. Metric Indicates the preference level for use of this node to forward packets to the IPv6 Address. Lower values indicate greater preference. Non-routers MUST set this field to zero. IPv6 Address Contains one of the IPv6 Addresses for this node. This may be another IPv6 Address for the same interface that sent the message, or may identify another interface on the same node which sent the message. This supports multiple IPv6 Addresses per interface, as well as multi-homed nodes. When a number of interfaces, such as point-to-point interfaces, may be aggregated with the same prefix, only one extension need be included. For advertisements, this enables the recipient node to determine the best next-hop without sending a Solicitation when the next-hop is on another interface attached to the same advertising node. Simpson expires in six months [Page 22]
DRAFT IPv6 Discovery Formats September 1994 For redirects, this enables the recipient node to determine the best next-hop without multiple redirects for each cluster. 2.5. System-Heard +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension | Length | | Prefix Size | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | Remaining LifeTime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ IPv6 Address ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MRU | | Speed | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Quality | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Advertisement Count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Error Count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Extension 4 Length 30 Prefix Size Indicates the number of bits in the IPv6 Address which define the cluster prefix width for the link. The value ranges from 0 to 126. If the IPv6 Address does not indicate a valid prefix, the value is zero. Sequence Number Contains the last heard sequence number from the node. Remaining LifeTime Indicates the seconds remaining before the entry is considered expired. IPv6 Address Contains the primary IPv6 Address for the node, taken from the Source field of the Advertisement heard. Simpson expires in six months [Page 23]
DRAFT IPv6 Discovery Formats September 1994 MRU Indicates the maximum size packet that the node will receive over the link. Speed Indicates the speed of the link over which the advertisement or solicitation was heard. Higher values indicate greater speed. The speed value is related to int( 10 * ln( speed / 100 ) ) in bits per second. 0 link is down 1 - 9 reserved 10 300 or less 24 1,200 96 1,544,000 T1 31 2,400 99 2,048,000 E1 38 4,800 106 4,000,000 Token Ring 42 7,200 110 6,312,000 T2 45 9,600 115 10,000,000 Ethernet 49 14,400 119 16,000,000 Token Ring 52 19,200 56 28,800 130 44,736,000 T3 59 38,400 142 155,520,000 STS-3,STM-1 63 57,600 202 622,080,000 STS-12,STM-4 64 64,000 216 2,488,320,000 STS-48,STM-16 71 128,000 73 153,600 78 256,000 Quality Contains an indication of the signal quality received from this node. Higher values indicate greater quality. Advertisement Count Indicates the number of advertisements that have been heard from the identified node. Error Count Indicates the number of errors which have been detected on the link with the identified node. This extension is included in the Advertisement message to indicate a node which has been heard. The MRU, Speed, Quality, Advertisement Count, and Error Count are primarily used for selecting among multiple paths in a wireless environment. Simpson expires in six months [Page 24]
DRAFT IPv6 Discovery Formats September 1994 2.6. Routing-Information +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension | Length |C|F| | Prefix Size | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | Preference | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ IPv6 Address ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Extension 5 Length 14 C Cluster bit. When this bit is set to 1, the IPv6 Cluster is entirely confined to the link. When forwarding, a node MAY use the prefix to determine whether a target node is on the link. F Foreign Agent bit. When this bit is set to 1, Mobile Registration through the Foreign Agent is required, even when the Mobile Node has acquired a transient Care-Of-Address. Prefix Size Indicates the number of bits in the IPv6 Address which define the cluster prefix width for the link. The value ranges from 0 to 126. If the IPv6 Address does not indicate a valid prefix, the value is zero. Preference Indicates the preference level for use of this node to forward packets to the IPv6 Address. Higher values indicate greater preference. IPv6 Address Contains one of the IPv6 Addresses for this interface. This extension is sent only by Routers. Simpson expires in six months [Page 25]
DRAFT IPv6 Discovery Formats September 1994 2.7. Service-Information +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension | Length | Service | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Data ... +-+-+-+-+-+-+-+-+-+-+-+- Extension 6 Length >= 2 Service The value of this field is usually the same as the well-known port number. Up-to-date values are specified in the most recent "Assigned Numbers" [RFC-1310]. Data This field is variable in length and contains Attribute information specific to the service. Simpson expires in six months [Page 26]
DRAFT IPv6 Discovery Formats September 1994 2.8. Transit-Information +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension | Length | | QoS | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Metric | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Extension 7 Length 6 QoS Indicates a quality of service for which transit will be accepted. Metric Indicates the preference level for use of this link to forward packets of the indicated Quality of Service. Lower values indicate greater preference. For advertisements, this indicates that a router will accept transit traffic for the service. If this extension is not included, other routers will treat the link as a stub cluster. For redirects, this indicates that the redirect is limited to only the particular service. If this extension is not included, the redirect includes all services. Simpson expires in six months [Page 27]
DRAFT IPv6 Discovery Formats September 1994 2.9. Redirected-Header +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension | Length | IPv6 Header ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Extension 8 Length 54 IPv6 Header 48 octets. This extension is included in the Local or Remote Redirect to verify the traffic that is being redirected. Simpson expires in six months [Page 28]
DRAFT IPv6 Discovery Formats September 1994 2.10. Maximum-Receive-Unit +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension | Length | MRU | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Extension 14 Length 2 MRU Indicates the maximum size packet that the node will receive over the link. The Maximum-Receive-Unit extension MUST be included in those messages sent from an interface for which there is no dependable MTU, such as Frame-Relay or Asynchronous Transfer Mode. It MUST NOT be included in messages such as the Remote Redirect which pass through intermediate nodes. Simpson expires in six months [Page 29]
DRAFT IPv6 Discovery Formats September 1994 2.11. Media-Access +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension | Length | Media Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Media Address ... +-+-+-+-+-+-+-+-+-+-+-+- Extension 15 Length >= 2 Media Type The value of this field is the same as the Hardware Type used in ARP. Up-to-date values are specified in the most recent "Assigned Numbers" [RFC-1310]. Media Address This field is variable in length and contains the media address which is used to access this node. The Media Address is always specified in Canonical order. The Media-Access extension MUST be included in those messages sent from an interface on a multi-access media. It MUST NOT be included in a message sent from a point-to-point interface, or in messages such as the Remote Redirect which pass through intermediate nodes. Simpson expires in six months [Page 30]
DRAFT IPv6 Discovery Formats September 1994 2.12. Mobile-Home Authentication Extension +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension | Length | Authenticator ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Extension 32 Length The number of data bytes in the Extension (16 when MD5 is used). Authenticator Variable length (128 bits for MD5). A hash value taken over a stream of bytes consisting of the shared secret, followed by (concatenated with) the fields in the Mobile Registration message beginning with the Type field, including all prior extensions, and the Type and Length of this extension, but not including the Authenticator field itself. This Authentication Extension is found in all Mobile Registration Requests and Replies. The value differs depending on the direction the message is sent, since the Mobile Registration Request and Reply have different fields. Simpson expires in six months [Page 31]
DRAFT IPv6 Discovery Formats September 1994 2.13. Minimal Encapsulation Extension +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Extension 64 Length 0 The Minimal Encapsulation Extension is found in Router Advertisements and Mobile Registration Requests. Simpson expires in six months [Page 32]
DRAFT IPv6 Discovery Formats September 1994 Security Considerations References [Eastlake] [IPv6-ICMP] [RFC-1305] [RFC-1310] Acknowledgements Extensive review by Alex Conta (DEC), and Dan McDonald (NRL). Author's Address Questions about this memo can also be directed to: William Allen Simpson Daydreamer Computer Systems Consulting Services 1384 Fontaine Madison Heights, Michigan 48071 Bill.Simpson@um.cc.umich.edu bsimpson@MorningStar.com Simpson expires in six months [Page 33]
DRAFT IPv6 Discovery Formats September 1994 Table of Contents 1. Additional ICMP Packets ............................... 1 1.1 Solicitation .................................... 2 1.1.1 General Solicitation ............................ 3 1.1.2 Router Solicitation ............................. 4 1.1.3 Service Solicitation ............................ 5 1.2 Advertisement ................................... 6 1.2.1 General Advertisement ........................... 7 1.2.2 Router Advertisement ............................ 8 1.2.3 Service Advertisement ........................... 10 1.2.4 Local Redirect .................................. 11 1.2.5 Remote Redirect ................................. 13 1.3 Mobile Registration Request ..................... 14 1.4 Mobile Registration Reply ....................... 17 2. Extensions ............................................ 19 2.1 Single Pad ...................................... 20 2.2 Multiple Pads ................................... 20 2.3 Change-Identifier ............................... 21 2.4 Other-Identifier ................................ 22 2.5 System-Heard .................................... 23 2.6 Routing-Information ............................. 25 2.7 Service-Information ............................. 26 2.8 Transit-Information ............................. 27 2.9 Redirected-Header ............................... 28 2.10 Maximum-Receive-Unit ............................ 29 2.11 Media-Access .................................... 30 2.12 Mobile-Home Authentication Extension ............ 31 2.13 Minimal Encapsulation Extension ................. 32 SECURITY CONSIDERATIONS ...................................... 33 REFERENCES ................................................... 33 ACKNOWLEDGEMENTS ............................................. 33 AUTHOR'S ADDRESS ............................................. 33