INTAREA R. Bonica
Internet-Draft R. Thomas
Updates: 4884 (if approved) Juniper Networks
Intended status: Standards Track J. Linkova
Expires: May 3, 2018 Google
C. Lenart
Verizon
M. Boucadair
Orange
October 30, 2017
PROBE: A Utility For Probing Interfaces
draft-ietf-intarea-probe-07
Abstract
This document describes a network diagnostic tool called PROBE.
PROBE is similar to PING, in that it can be used to test the status
of a probed interface. It differs from PING in that it does not
require bidirectional connectivity between the probing and probed
interfaces. Alternatively, PROBE requires bidirectional connectivity
between the probing interface and a proxy interface. The proxy
interface can reside on the same node as the probed interface or it
can reside on a node to which the probed interface is directly
connected. This document updates RFC 4884.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
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 inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 3, 2018.
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Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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to this document. Code Components extracted from this document must
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. ICMP Extended Echo Request . . . . . . . . . . . . . . . . . 4
2.1. Interface Identification Object . . . . . . . . . . . . . 6
3. ICMP Extended Echo Reply . . . . . . . . . . . . . . . . . . 7
4. ICMP Message Processing . . . . . . . . . . . . . . . . . . . 9
4.1. Code Field Processing . . . . . . . . . . . . . . . . . . 10
5. Use-Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6. Updates to RFC 4884 . . . . . . . . . . . . . . . . . . . . . 12
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
8. Security Considerations . . . . . . . . . . . . . . . . . . . 13
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
9.1. Normative References . . . . . . . . . . . . . . . . . . 14
9.2. Informative References . . . . . . . . . . . . . . . . . 15
Appendix A. The PROBE Application . . . . . . . . . . . . . . . 15
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
Network operators use PING [RFC2151] to test bidirectional
connectivity between two interfaces. For the purposes of this
document, we will call these interfaces the probing and probed
interfaces. PING sends an ICMP [RFC0792] [RFC4443] Echo message from
the probing interface to the probed interface. The probing interface
resides on a probing node while the probed interface resides on a
probed node.
If the probed interface receives the ICMP Echo message, it returns an
ICMP Echo Reply. When the probing interface receives the ICMP Echo
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Reply, it has verified bidirectional connectivity between the probing
and probed interfaces. Specifically, it has verified that:
o The probing node can reach the probed interface
o The probed interface is active
o The probed node can reach the probing interface
o The probing interface is active
This document describes a network diagnostic tool called PROBE.
PROBE is similar to PING, in that it can be used to test the status
of a probed interface. It differs from PING in that it does not
require bidirectional connectivity between the probing and probed
interfaces. Alternatively, PROBE requires bidirectional connectivity
between the probing interface and a proxy interface. The proxy
interface can reside on the same node as the probed interface or it
can reside on a node to which the probed interface is directly
connected. Section 5 of this document describes scenarios in which
this characteristic is useful.
Like PING, PROBE executes on a probing node. It sends an ICMP
Extended Echo message from a local interface, called the probing
interface, to a proxy interface. The proxy interface resides on a
probed node.
The ICMP Extended Echo Request contains an ICMP Extension Structure
and the ICMP Extension Structure contains an Interface Identification
Object. The Interface Identification Object identifies the probed
interface. The probed interface can reside on the probed node or it
can be directly connected to the probed node.
When the proxy interface receives the ICMP Extended Echo Request, it
executes access control procedures. If access is granted, the probed
node determines the status of the probed interface and returns an
ICMP Extended Echo Reply Message. The ICMP Extended Echo Reply
indicates the status of the probed interface.
If the probed interface resides on the probed node, PROBE determines
the status of the probed interface as it would determine its MIB-II
[RFC2863] ifOperStatus. If ifOperStatus is equal to up (1), PROBE
reports that the probed interface is active. Otherwise, PROBE
reports that the probed interface is inactive.
If the probed interface resides on a node that is directly connected
to the probed node, PROBE reports that the interface is up if it
appears in the IPv4 Address Resolution Protocol (ARP) table [RFC0826]
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or IPv6 Neighbor Cache [RFC4861]. Otherwise, it reports that the
interface does not exist.
1.1. Terminology
This document uses the following terms:
o Probing node - The node upon which PROBE executes
o Probing interface - The interface from which an ICMP Extended Echo
originates
o Proxy interface - The interface to which the ICMP Extended Echo
message is sent
o Probed node - The node upon which the proxy interface resides
o Probed interface - The interface whose status is being queried
1.2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. ICMP Extended Echo Request
The ICMP Extended Echo Request message is defined for both ICMPv4 and
ICMPv6. Like any ICMP message, the ICMP Extended Echo Request
message is encapsulated in an IP header. The ICMPv4 version of the
Extended Echo Request message is encapsulated in an IPv4 header,
while the ICMPv6 version is encapsulated in an IPv6 header.
Figure 1 depicts the ICMP Extended Echo Request message.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier |Sequence Number| Reserved |L|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ICMP Extension Structure
Figure 1: ICMP Extended Echo Request Message
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IP Header fields:
o Source Address: The Source Address identifies the probing
interface. It MUST be valid IPv4 or IPv6 unicast address.
o Destination Address: The Destination Address identifies the proxy
interface. It can be a unicast, multicast or anycast address.
ICMP fields:
o Type: Extended Echo Request. The value for ICMPv4 is TTTT0. <RFC
Editor: Please replace TTT0 with the ICMPv4 type number for
Extended Echo Request>. The value for ICMPv6 is TTT1. <RFC
Editor: Please replace TTT1 with the ICMPv6 type number for
Extended Echo Request> .
o Code: 0
o Checksum: For ICMPv4, see RFC 792. For ICMPv6, see RFC 4443.
o Identifier: An identifier to aid in matching Extended Echo Replies
to Extended Echo Requests. May be zero.
o Sequence Number: A sequence number to aid in matching Extended
Echo Replies to Extended Echo Requests. May be zero.
o Reserved: This field MUST be set to zero and ignored upon receipt.
o L (local) - The L-bit is set if the probed interface resides on
the probed node. The L-bit is clear if the probed interface is
directly connected to the probed node.
o ICMP Extension Structure: The ICMP Extension Structure identifies
the probed interface.
Section 7 of [RFC4884] defines the ICMP Extension Structure. As per
RFC 4884, the Extension Structure contains exactly one Extension
Header followed by one or more objects. When applied to the ICMP
Extended Echo Request message, the ICMP Extension Structure MUST
contain one or two instances of the Interface Identification Object
(Section 2.1).
In most cases, a single instance of the Interface Identification
Object identifies the probed interface. However, in some cases, a
second instance is required for disambiguation.
If the L-bit is set, the Interface Identification Object identifies
the probed interface by name, index or address. It the L-bit is
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clear, the Interface Identification Object identifies the probed
interface by address.
If the Interface Identification Object identifies the probed
interface by address, that address can be a member of any address
family. For example, an ICMPv4 Extended Echo Request message can
carry an Interface Identification Object that identifies the probed
interface by IPv4, IPv6 or IEEE 802 address. Likewise, an ICMPv6
Extended Echo Request message can carry an Interface Identification
Object that identifies the probed interface by IPv4, IPv6 or IEEE 802
address.
2.1. Interface Identification Object
The Interface Identification Object identifies the probed interface
by name, index, or address. Like any other ICMP Extension Object, it
contains an Object Header and Object Payload. The Object Header
contains the following fields:
o Class-Num: Interface Identification Object. Value is TTT2. <RFC
Editor: Please replace TTT2 with the Class-Num for the Interface
Identification Object>
o C-type: Values are: (1) Identifies Interface By Name, (2)
Identifies Interface By Index, and (3) Identifies Interface By
Address
o Length: Length of the object, measured in octets, including the
object header and object payload.
If the Interface Identification Object identifies the probed
interface by name, the object payload MUST be the MIB-II [RFC2863]
ifName. If the object payload would not otherwise terminate on a
32-bit boundary, it MUST be padded with ASCII NULL characters.
If the Interface Identification Object identifies the probed
interface by index, the length is equal to 8 and the payload contains
the MIB-II ifIndex [RFC2863].
If the Interface Identification Object identifies the probed
interface by address, the payload is as depicted in Figure 2.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI | Address Length| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Address ....
Figure 2: Interface Identification Object - C-type 3 Payload
Payload fields are defined as follows:
o Address Family Identifier (AFI): This 16-bit field identifies the
type of address represented by the Address field. All values
found in the IANA registry of Address Family Numbers (available
from <https://www.iana.org/assignments/address-family-numbers/
address-family-numbers.xhtml>) are valid in this field.
o Reserved: This field MUST be set to zero and ignored upon receipt.
o Address Len - Number of significant bytes contained by the Address
field. (The address field contains significant bytes and padding
bytes)
o Address: This variable-length field represents an address
associated with the probed interface. If the address field would
not otherwise terminate on a 32-bit boundary, it MUST be padded
with zeros.
3. ICMP Extended Echo Reply
The ICMP Extended Echo Reply message is defined for both ICMPv4 and
ICMPv6. Like any ICMP message, the ICMP Extended Echo Reply message
is encapsulated in an IP header. The ICMPv4 version of the Extended
Echo Reply message is encapsulated in an IPv4 header, while the
ICMPv6 version is encapsulated in an IPv6 header.
Figure 3 depicts the ICMP Extended Echo Reply message.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier |Sequence Number| Resvd |A|F|S|E|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: ICMP Extened Echo Reply Message
IP Header fields:
o Source address: Copied from the Destination Address field of the
invoking Extended Echo Request message
o Destination address: Copied from the Source Address field of the
invoking Extended Echo Request message
ICMP fields:
o Type: Extended Echo Reply. The value for ICMPv4 is TTT3. <RFC
Editor: Please replace TTT3 with the ICMPv4 type number for
Extended Echo Reply>. The value for ICMPv6 is TTT4. <RFC Editor:
Please replace TTT4 with the ICMPv6 type number for Extended Echo
Reply>.
o Code: (0) No Error, (1) Malformed Query, (2) No Such Interface,
(3) Multiple Interfaces Satisfy Query
o Checksum: For ICMPv4, see RFC 792. For ICMPv6, see RFC 4443
o Identifier: Copied from the Identifier field of the invoking
Extended Echo Request packet
o Sequence Number: Copied from the Sequence Number field of the
invoking Extended Echo Request packet
o Resvd - This field MUST be set to zero and ignored upon receipt
o A (Active) - The A-bit is set if Code is equal to zero and the
probed interface is active. Otherwise, the A-bit is clear.
o F (IPv4) - The F-bit is set if the A-bit is also set and IPv4 is
running on the probed interface. Otherwise, the F-bit is clear.
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o S (IPv6) - The S-bit is set if the A-bit is also set and IPv6 is
running on the probed interface. Otherwise, the S-bit is clear.
o E (Ethernet) - The E-bit is set if the A-bit is also set and
Ethernet is running on the probed interface. Otherwise, the E-bit
is clear.
4. ICMP Message Processing
When a node receives an ICMP Extended Echo Request message and any of
the following conditions apply, the node MUST silently discard the
incoming message:
o The node does not recognize ICMP Extended Echo Request messages
o The node has not explicitly enabled ICMP Extended Echo
functionality
o The incoming ICMP Extend Echo Request carries a source address
that is not explicitly authorized for the incoming ICMP Extended
Echo Request L-bit setting
o The incoming ICMP Extend Echo Request carries a source address
that is not explicitly authorized for the incoming ICMP Extended
Echo Request type (i.e., by ifName, by IfIndex, by Address)
o The Source Address of the incoming messages is not a unicast
address
Otherwise, when a node receives an ICMPv4 Extended Echo Request, it
MUST format an ICMP Extended Echo Reply as follows:
o Don't Fragment flag (DF) is 1
o More Fragments flag is 0
o Fragment Offset is 0
o TTL is 255
o Protocol is ICMP
When a node receives an ICMPv6 Extended Echo Request, it MUST format
an ICMPv6 Extended Echo Reply as follows:
o Hop Limit is 255
o Next Header is ICMPv6
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In either case, the responding node MUST:
o Copy the source address from the Extended Echo Request message to
the destination address of the Extended Echo Reply
o Copy the destination address from the Extended Echo Request
message to the source address of the Extended Echo Reply
o Set the DiffServ codepoint to CS0 [RFC4594]
o Set the ICMP Type to Extended Echo Reply
o Copy the Identifier from the Extended Echo Request message to the
Extended Echo Reply
o Copy the Sequence Number from the Extended Echo Request message to
the Extended Echo Reply
o Set the Code field as described Section 4.1
o If the Code Field is equal to No Error (0) and the L-bit is clear,
set the A-Bit.
o If the Code Field is equal to No Error (0) and the L-bit is set
and the probed interface is active, set the A-bit.
o If the A-bit is set, set the F-bit, S-bit and E-bit as
appropriate. Otherwise, clear the F, S and E bits.
o Set the checksum appropriately
o Forward the ICMP Extended Echo Reply to its destination
4.1. Code Field Processing
The Code field MUST be set to Malformed Query (1) if any of the
following conditions apply:
o The ICMP Extended Echo Request does not include an ICMP Extension
Structure
o The ICMP Extension Structure does not include an Interface
Identification Object
o The ICMP Extension Structure contains more than two Interface
Identification Objects
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o The L-bit is clear and the Interface Identification Object
identifies the probed interface by ifName or ifIndex
o The query is otherwise malformed
The Code field MUST be set to No Such Interface (2) if any of the
following conditions apply:
o The L-bit is set and the ICMP Extension Structure does not
identify any local interfaces
o The L-bit is clear and the address or addresses found in the
Interface Identification object appear in neither the IPv4 Address
Resolution Protocol (ARP) Table nor the IPv6 Neighbor Cache
The Code field MUST be set to Multiple Interfaces Satisfy Query (3)
if any of the following conditions apply:
o The L-bit is set and the ICMP Extension Structure identifies more
than one local interfaces
o The L-bit is clear and the address or addresses found in the
Interface Identification object map to multiple IPv4 ARP or IPv6
Neighbor Cache entries
Otherwise, the Code field MUST be set to No Error (0)
5. Use-Cases
In the scenarios listed below, network operators can use PROBE to
determine the status of a probed interface, but cannot use PING for
the same purpose. In all scenarios, assume bidirectional
connectivity between the probing and proxy interfaces. However,
bidirectional connectivity between the probing and probed interfaces
is lacking.
o The probed interface is unnumbered
o The probing and probed interfaces are not directly connected to
one another. The probed interface has an IPv6 link-local address,
but does not have a more globally scoped address
o The probing interface runs IPv4 only while the probed interface
runs IPv6 only
o The probing interface runs IPv6 only while the probed interface
runs IPv4 only
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o For lack of a route, the probing node cannot reach the probed
interface.
6. Updates to RFC 4884
Section 4.6 of RFC 4884 provides a list of extensible ICMP messages
(i.e., messages that can carry the ICMP Extension Structure). This
document adds the ICMP Extended Echo message and the ICMP Extended
Echo Reply message to that list.
7. IANA Considerations
This document requests the following actions from IANA:
o Add an entry to the "ICMP Type Number" registry, representing the
Extended Echo Request. This entry has one code (0).
o Add an entry to the "Internet Control Message Protocol version 6
(ICMPv6) Parameters" registry, representing the Extended Echo
Request. This entry has one code (0).
o Add an entry to the "ICMP Type Number" registry, representing the
Extended Echo Reply. This entry has the following codes: (0) No
Error, (1) Malformed Query, (2) No Such Interface, (3) Multiple
Interfaces Satisfy Query. Protocol Flag Bit mappings are as
follows: Bit 0 (IPv4), Bit 1 (IPv6), Bit 2 (Ethernet), Bits 3-15
(Reserved).
o Add an entry to the "Internet Control Message Protocol version 6
(ICMPv6) Parameters" registry, representing the Extended Echo
Reply. This entry has the following codes: (0) No Error, (1)
Malformed Query, (2) No Such Interface, (3) Multiple Interfaces
Satisfy Query. Protocol Flag Bit mappings are as follows: Bit 0
(IPv4), Bit 1 (IPv6), Bit 2 (Ethernet), Bits 3-15 (Reserved).
o Add an entry to the "ICMP Extension Object Classes and Class Sub-
types" registry, representing the Interface Identification Object.
It has C-types Reserved (0), Identifies Interface By Name (1),
Identifies Interface By Index (2), Identifies Interface By Address
(3)
Note to RFC Editor: this section may be removed on publication as an
RFC.
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8. Security Considerations
The following are legitimate uses of PROBE:
o to determine the operational status of an interface
o to determine which protocols (e.g., IPv4, IPv6) are active on an
interface
However, malicious parties can use PROBE to obtain additional
information. For example, a malicious party can use PROBE to
discover interface names. Having discovered an interface name, the
malicious party may be able to infer additional information.
Additional information may include:
o interface bandwidth
o the type of device that supports the interface (e.g., vendor
identity)
o the operating system version that the above-mentioned device
executes
Understanding this risk, network operators establish policies that
restrict access to ICMP Extended Echo functionality. In order to
enforce these polices, nodes that support ICMP Extended Echo
functionality MUST support the following configuration options:
o Enable/disable ICMP Extended Echo functionality. By default, ICMP
Extend Echo functionality is disabled.
o Define enabled L-bit settings. By default, L-bit set is enabled
and L-bit clear is disabled.
o Define enabled query types (i.e., by ifName, by ifIndex, by
Address). By default, all query types are disabled.
o For each enabled query type, define the prefixes from which ICMP
Extended Echo Request messages are permitted
o For each interface, determine whether ICMP Echo Request messages
are accepted
When a node receives an ICMP Extended Echo Request message that it is
not configured to support, it MUST silently discard the message. See
Section 4 for details.
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PROBE MUST NOT leak information about one Virtual Private Network
(VPN) into another. Therefore, when a node receives an ICMP Extended
Echo Request and the proxy interface is in a different VPN than the
probed interface, the node MUST return an ICMP Extended Echo Reply
with error code equal to (2) No Such Interface.
In order to protect local resources, implementations SHOULD rate-
limit incoming ICMP Extended Echo Request messages.
9. References
9.1. Normative References
[RFC0792] Postel, J., "Internet Control Message Protocol", STD 5,
RFC 792, DOI 10.17487/RFC0792, September 1981,
<https://www.rfc-editor.org/info/rfc792>.
[RFC0826] Plummer, D., "Ethernet Address Resolution Protocol: Or
Converting Network Protocol Addresses to 48.bit Ethernet
Address for Transmission on Ethernet Hardware", STD 37,
RFC 826, DOI 10.17487/RFC0826, November 1982,
<https://www.rfc-editor.org/info/rfc826>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group
MIB", RFC 2863, DOI 10.17487/RFC2863, June 2000,
<https://www.rfc-editor.org/info/rfc2863>.
[RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet
Control Message Protocol (ICMPv6) for the Internet
Protocol Version 6 (IPv6) Specification", STD 89,
RFC 4443, DOI 10.17487/RFC4443, March 2006,
<https://www.rfc-editor.org/info/rfc4443>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007,
<https://www.rfc-editor.org/info/rfc4861>.
[RFC4884] Bonica, R., Gan, D., Tappan, D., and C. Pignataro,
"Extended ICMP to Support Multi-Part Messages", RFC 4884,
DOI 10.17487/RFC4884, April 2007,
<https://www.rfc-editor.org/info/rfc4884>.
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9.2. Informative References
[RFC2151] Kessler, G. and S. Shepard, "A Primer On Internet and TCP/
IP Tools and Utilities", FYI 30, RFC 2151,
DOI 10.17487/RFC2151, June 1997,
<https://www.rfc-editor.org/info/rfc2151>.
[RFC4594] Babiarz, J., Chan, K., and F. Baker, "Configuration
Guidelines for DiffServ Service Classes", RFC 4594,
DOI 10.17487/RFC4594, August 2006,
<https://www.rfc-editor.org/info/rfc4594>.
Appendix A. The PROBE Application
The PROBE application accepts input parameters, sets a counter and
enters a loop to be exited when the counter is equal to zero. On
each iteration of the loop, PROBE emits an ICMP Extended Echo
Request, decrements the counter, sets a timer, waits for the timer to
expire. If an expected ICMP Extended Echo Reply arrives while PROBE
is waiting for the timer to expire, PROBE relays information returned
by that message to its user. However, on each iteration of the loop,
PROBE waits for the timer to expire, regardless of whether an
Extended Echo Reply message arrives.
PROBE accepts the following parameters:
o Count
o Wait
o Probing Interface Address
o Hop Count
o Proxy Interface Address
o Local
o Probed Interface Identifier
Count is a positive integer whose default value is 3. Count
determines the number of times that PROBE iterates through the above-
mentioned loop.
Wait is a positive integer whose minimum and default values are 1.
Wait determines the duration of the above-mentioned timer, measured
in seconds.
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Probing Interface Address specifies the source address of ICMP
Extended Echo Request. The Probing Interface Address MUST be a
unicast address and MUST identify an interface that is local to the
probing node.
The Proxy Interface Address identifies the interface to which the
ICMP Extended Echo Request message is sent. It can be an IPv4 or
IPv6 address. If it is an IPv4 address, PROBE emits an ICMPv4
message. If it is an IPv6 address, PROBE emits an ICMPv6 message.
Local is a boolean value. It is TRUE if the proxy and probed
interfaces both reside on the probed node. It is FALSE if the proxy
interface resides on the probed node and the probed interface is
directly connected to the probed node.
The probed interface is the interface whose status is being queried.
It is identified by one of the following:
o an interface name
o an address from any address family (e.g., IPv4, IPv6, IEEE 802,
48-bit MAC, 64-bit MAC)
o an ifIndex
If the probed interface identifier is an address, it does not need to
be of the same address family as the proxy interface address. For
example, PROBE accepts an IPv4 destination interface address and an
IPv6 probed interface identifier
Acknowledgments
Thanks to Sowmini Varadhan, Jeff Haas, Carlos Pignataro, Jonathan
Looney, Dave Thaler, Mikio Hara and Joe Touch for their thoughtful
review of this document.
Authors' Addresses
Ron Bonica
Juniper Networks
2251 Corporate Park Drive
Herndon, Virginia 20171
USA
Email: rbonica@juniper.net
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Reji Thomas
Juniper Networks
Elnath-Exora Business Park Survey
Bangalore, Karnataka 560103
India
Email: rejithomas@juniper.net
Jen Linkova
Google
1600 Amphitheatre Parkway
Mountain View, California 94043
USA
Email: furry@google.com
Chris Lenart
Verizon
22001 Loudoun County Parkway
Ashburn, Virginia 20147
USA
Email: chris.lenart@verizon.com
Mohamed Boucadair
Orange
Rennes 35000
France
Email: mohamed.boucadair@orange.com
Bonica, et al. Expires May 3, 2018 [Page 17]