DHC M. Stapp
Internet-Draft B. Volz
Expires: June 23, 2005 Cisco Systems, Inc.
Y. Rekhter
Juniper Networks
December 23, 2004
The DHCP Client FQDN Option
<draft-ietf-dhc-fqdn-option-08.txt>
Status of this Memo
This document is an Internet-Draft and is subject to all provisions
of section 3 of RFC 3667. By submitting this Internet-Draft, each
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RFC 3668.
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Copyright Notice
Copyright (C) The Internet Society (2004).
Abstract
This document specifies a DHCP for IPv4, DHCPv4, option which can be
used to exchange information about a DHCPv4 client's fully-qualified
domain name and about responsibility for updating the DNS RR related
to the client's address assignment.
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Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1 Models of Operation . . . . . . . . . . . . . . . . . . . 3
3. The Client FQDN Option . . . . . . . . . . . . . . . . . . . . 4
3.1 The Flags Field . . . . . . . . . . . . . . . . . . . . . 5
3.2 The RCODE Fields . . . . . . . . . . . . . . . . . . . . . 6
3.3 The Domain Name Field . . . . . . . . . . . . . . . . . . 6
3.3.1 Deprecated ASCII Encoding . . . . . . . . . . . . . . 7
4. DHCP Client Behavior . . . . . . . . . . . . . . . . . . . . . 7
4.1 Interaction With Other Options . . . . . . . . . . . . . . 7
4.2 Client Desires to Update A RRs . . . . . . . . . . . . . . 8
4.3 Client Desires Server to Do DNS Updates . . . . . . . . . 8
4.4 Client Desires No Server DNS Updates . . . . . . . . . . . 8
4.5 Domain Name and DNS Update Issues . . . . . . . . . . . . 9
5. DHCP Server Behavior . . . . . . . . . . . . . . . . . . . . . 9
5.1 When to Perform DNS Updates . . . . . . . . . . . . . . . 10
6. DNS Update Conflicts . . . . . . . . . . . . . . . . . . . . . 11
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
8. Security Considerations . . . . . . . . . . . . . . . . . . . 12
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
10.1 Normative References . . . . . . . . . . . . . . . . . . . . 13
10.2 Informative References . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 14
Intellectual Property and Copyright Statements . . . . . . . . 15
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1. Terminology
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 [1].
2. Introduction
DNS ([2], [3]) maintains (among other things) the information about
the mapping between hosts' Fully Qualified Domain Names (FQDNs) [7]
and IP addresses assigned to the hosts. The information is
maintained in two types of Resource Records (RRs): A and PTR. The
DNS update specification ([4]) describes a mechanism that enables DNS
information to be updated over a network.
The Dynamic Host Configuration Protocol for IPv4 (DHCPv4 or just DHCP
in this document) [5] provides a mechanism by which a host (a DHCP
client) can acquire certain configuration information, along with its
address. This document specifies a DHCP option, the Client FQDN
option, which can be used by DHCP clients and servers to exchange
information about the client's fully-qualified domain name for an
address and who has the responsibility for updating the DNS with the
associated A and PTR RRs.
2.1 Models of Operation
When a DHCP client acquires a new address, a site's administrator may
desire that one or both of the A RR for the client's FQDN and the PTR
RR for the acquired address be updated. Therefore, two separate DNS
update transactions may occur. Acquiring an address via DHCP
involves two entities: a DHCP client and a DHCP server. In principle
each of these entities could perform none, one, or both of the
transactions. However, in practice not all permutations make sense.
The DHCP Client FQDN option is primarily intended to operate in the
following two cases:
1. DHCP client updates the A RR, DHCP server updates the PTR RR
2. DHCP server updates both the A and the PTR RRs
The only difference between these two cases is whether the FQDN to IP
address mapping is updated by a DHCP client or by a DHCP server. The
IP address to FQDN mapping is updated by a DHCP server in both cases.
The reason these two are important, while others are unlikely, has to
do with authority over the respective DNS domain names. A DHCP
client may be given authority over mapping its own A RRs, or that
authority may be restricted to a server to prevent the client from
listing arbitrary addresses or associating its address with arbitrary
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domain names. In all cases, the only reasonable place for the
authority over the PTR RRs associated with the address is in the DHCP
server that allocates the address.
Note: A third case is supported - the client requests that the server
perform no updates. However, this case is presumed to be rare
because of the authority issues.
In any case, whether a site permits all, some, or no DHCP servers and
clients to perform DNS updates into the zones which it controls is
entirely a matter of local administrative policy. This document does
not require any specific administrative policy, and does not propose
one. The range of possible policies is very broad, from sites where
only the DHCP servers have been given credentials that the DNS
servers will accept, to sites where each individual DHCP client has
been configured with credentials which allow the client to modify its
own domain name. Compliant implementations may support some or all
of these possibilities. Furthermore, this specification applies only
to DHCP client and server processes: it does not apply to other
processes which initiate DNS updates.
This document describes a new DHCP option which a client can use to
convey all or part of its domain name to a DHCP server.
Site-specific policy determines whether DHCP servers use the names
that clients offer or not, and what DHCP servers may do in cases
where clients do not supply domain names.
3. The Client FQDN Option
To update the IP address to FQDN mapping a DHCP server needs to know
the FQDN of the client to which the server leases the address. To
allow the client to convey its FQDN to the server this document
defines a new DHCP option, called "Client FQDN". The Client FQDN
option also contains Flags, which DHCP servers can use to convey
information about DNS updates to clients, and two deprecated RCODEs.
Clients MAY send the Client FQDN option, setting appropriate Flags
values, in both their DHCPDISCOVER and DHCPREQUEST messages. If a
client sends the Client FQDN option in its DHCPDISCOVER message, it
MUST send the option in subsequent DHCPREQUEST messages.
Only one FQDN MAY appear in a message. As per [13], multiple
instances of this option in a message SHOULD be concatentated.
The code for this option is 81. Its minimum length is 3.
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The Format of the Client FQDN Option is:
Code Len Flags RCODE1 RCODE2 Domain Name
+------+------+------+------+------+------+--
| 81 | n | | | | ...
+------+------+------+------+------+------+--
3.1 The Flags Field
The Format of the Flags Field is:
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
| MBZ |N|E|O|S|
+-+-+-+-+-+-+-+-+
The "S" bit indicates whether the server SHOULD or SHOULD NOT perform
the A RR (FQDN to address) DNS updates. A client sets the bit to 0
to indicate the server SHOULD NOT perform the updates and 1 to
indicate the server SHOULD perform the updates. The state of the bit
in the reply from the server indicates the action to be taken by the
server; if 1, the server has taken responsibility for A RR updates
for the FQDN.
The "O" bit indicates whether the server has overridden the client's
preference for the "S" bit. A client MUST set this bit to 0. A
server MUST set this bit to 1 if the "S" bit in its reply to the
client does not match the "S" bit received from the client.
The "N" bit indicates whether the server SHOULD NOT perform any DNS
updates. A client sets this bit to 0 to request that the server
SHOULD perform updates (the PTR RR and possibly the A RR based on the
"S" bit) or to 1 to request that the server SHOULD NOT perform any
DNS updates. A server sets the "N" bit to indicate whether it SHALL
(0) or SHALL NOT (1) perform DNS updates. If the "N" bit is 1, the
"S" bit MUST be 0.
The "E" bit indicates the encoding of the Domain Name field. 1
indicates DNS-style binary encoding, without compression, as
described in RFC 1035 [3] and SHOULD be used by clients. 0 indicates
a now deprecated ASCII encoding. Servers MUST use the same encoding
as received from the client. Server implementers SHOULD note that
earlier draft versions of this specification permitted an ASCII
encoding of the domain name and this encoding MUST be used if the "E"
bit is 0. Clients which implemented this encoding were deployed
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before this specification was completed. Server implementers which
need to support these clients need to see the section on the
deprecated ASCII encoding (Section 3.3.1).
The remaining bits in the Flags field are reserved for future
assignment. DHCP clients and servers which send the Client FQDN
option MUST clear the MBZ bits, and they MUST ignore these bits.
3.2 The RCODE Fields
The RCODE1 and RCODE2 fields are deprecated. A client SHOULD set
these to 0 when sending the option and SHOULD ignore them on receipt.
A server SHOULD set these to 255 when sending the option and MUST
ignore them on receipt.
As this option with these fields is already in wide use, the fields
are retained. These fields were originally defined for use by a DHCP
server to indicate to a DHCP client the Response Code from any A
(RCODE1) or PTR (RCODE2) RR DNS updates it has performed or a value
of 255 was used to indicate that an update had been initiated but had
not yet completed. Each of these fields is one byte long. These
fields were defined before EDNS0 [10], which describes a mechanism
for extending the length of a DNS RCODE to 12 bits, which is another
reason to deprecate them.
If the client needs to confirm the DNS update has been done, it MAY
use a DNS query to check whether the mapping is up to date. However,
depending on the load on the DHCP and DNS servers and the DNS
propagation delays, the client can only infer success. If the
information is not found to be up to date in DNS, the servers might
not have completed the updates or zone transfers, or not yet updated
their caches.
3.3 The Domain Name Field
The Domain Name part of the option carries all or part of the FQDN of
a DHCP client. The data in the Domain Name field SHOULD appear in
uncompressed DNS encoding as specified in RFC 1035 [3]. If the DHCP
client uses DNS encoding, it MUST set to 1 the the "E" bit in the
Flags field. In order to determine whether the FQDN has changed
between message exchanges, the client and server MUST NOT alter the
Domain Name field contents unless the FQDN has actually changed.
A client MAY be configured with a fully-qualified domain name or with
a partial name that is not fully-qualified. If a client knows only
part of its name, it MAY send a name that is not fully-qualified,
indicating that it knows part of the name but does not necessarily
know the zone in which the name is to be embedded.
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To send a fully-qualified domain name, the Domain Name field is set
to the DNS encoded domain name including the terminating zero-length
label. To send a partial name, the Domain Name field is set to the
DNS encoded domain name without the terminating zero-length label.
A client MAY also leave the Domain Name field empty if it desires the
server to provide a name.
3.3.1 Deprecated ASCII Encoding
The DNS encoding specified above MUST be supported by DHCP servers.
However, a substantial population of clients implemented an earlier
draft version of this specification, which permitted an ASCII
encoding of the Domain Name field. Server implementations SHOULD be
aware that clients which send the Client FQDN option with the "E" bit
set to 0 are using an ASCII encoding of the Domain Name field.
Servers MAY be prepared to return an ASCII encoded version of the
Domain Name field to such clients. Servers that are not prepared to
return an ASCII encoded version MUST ignore the Client FQDN option if
the "E" bit is 0. The use of ASCII encoding in this option SHOULD be
considered deprecated.
A DHCP client which used ASCII encoding was permitted to suggest a
single label if it was not configured with a fully-qualified name.
Such clients send a single label as a series of ASCII characters in
the Domain Name field, excluding the "." (dot) character. Such
clients SHOULD follow the character-set recommendations of RFC 1034
[2] and RFC 1035 [3].
Server implementers SHOULD also be aware that some client software
could be using UTF-8 [9] character encoding. This information is
included for informational purposes only; this specification does not
require any support for UTF-8.
4. DHCP Client Behavior
The following describes the behavior of a DHCP client that implements
the Client FQDN option.
4.1 Interaction With Other Options
Other DHCP options MAY carry data that is related to the Domain Name
field of the Client FQDN option. The Host Name option [8], for
example, contains an ASCII string representation of the client's host
name. In general, a client does not need to send redundant data, and
therefore clients which send the Client FQDN option in their messages
MUST NOT also send the Host Name option. Clients which receive both
the Host Name option and the Client FQDN option from a server SHOULD
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prefer Client FQDN option data. Section 5 instructs servers to
ignore the Host Name option in client messages which include the
Client FQDN option.
4.2 Client Desires to Update A RRs
If a client that owns/maintains its own FQDN wants to be responsible
for updating the FQDN to IP address mapping for the FQDN and
address(es) used by the client, the client MUST include the Client
FQDN option in the DHCPREQUEST message originated by the client. A
DHCP client MAY choose to include the Client FQDN option in its
DHCPDISCOVER messages as well as its DHCPREQUEST messages. The "S"
bit in the Flags field in the option MUST be 0. The "O" and "N" bits
MUST be 0.
Once the client's DHCP configuration is completed (the client
receives a DHCPACK message and successfully completes a final check
on the parameters passed in the message), the client MAY originate an
update for the A RR (associated with the client's FQDN) unless the
server has set the "S" bit to 1. If the "S" is 1, the DHCP client
MUST NOT initiate an update for the name in the Domain Name field.
4.3 Client Desires Server to Do DNS Updates
A client can choose to delegate the responsibility for updating the
FQDN to IP address mapping for the FQDN and address(es) used by the
client to the server. In order to inform the server of this choice,
the client SHOULD include the Client FQDN option in its DHCPREQUEST
message and MAY include the Client FQDN option in its DHCPDISCOVER.
The "S" bit in the Flags field in the option MUST be 1. The "O" and
"N" bits MUST be 0.
4.4 Client Desires No Server DNS Updates
A client can choose to request that the server perform no DNS updates
on its behalf. In order to inform the server of this choice, the
client SHOULD include the Client FQDN option in its DHCPREQUEST
message and MAY include the Client FQDN option in its DHCPDISCOVER.
The "N" bit in the Flags field in the option MUST be 1 and the "S"
and "O" bits MUST be 0.
Once the client's DHCP configuration is completed (the client
receives a DHCPACK message and successfully completes a final check
on the parameters passed in the message), the client MAY originate
its DNS updates provided the server's "N" bit is 1. If the server's
"N" bit is 0, the server MAY perform the PTR RR updates; and, MAY
also perform the A RR updates if the "S" bit is 1.
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4.5 Domain Name and DNS Update Issues
As there is a possibility that the DHCP server is configured to
complete or replace a domain name that the client sends, the client
MAY find it useful to send the Client FQDN option in its DHCPDISCOVER
messages. If the DHCP server returns different Domain Name data in
its DHCPOFFER message, the client could use that data in performing
its own eventual A RR update, or in forming the Client FQDN option
that it sends in its DHCPREQUEST message. There is no requirement
that the client send identical Client FQDN option data in its
DHCPDISCOVER and DHCPREQUEST messages. In particular, if a client
has sent the Client FQDN option to its server, and the configuration
of the client changes so that its notion of its domain name changes,
it MAY send the new name data in a Client FQDN option when it
communicates with the server again. This MAY cause the DHCP server
to update the name associated with the PTR record, and, if the server
updated the A record representing the client, to delete that record
and attempt an update for the client's current domain name.
A client that delegates the responsibility for updating the FQDN to
IP address mapping to a server will not receive any indication
(either positive or negative) from the server whether the server was
able to perform the update. The client MAY use a DNS query to check
whether the mapping is up to date (see Section 3.2).
If a client releases its lease prior to the lease expiration time and
the client is responsible for updating its A RR, the client SHOULD
delete the A RR associated with the leased address before sending a
DHCPRELEASE message. Similarly, if a client was responsible for
updating its A RR, but is unable to renew its lease, the client
SHOULD attempt to delete the A RR before its lease expires. A DHCP
client which has not been able to delete an A RR which it added
(because it has lost the use of its DHCP IP address) SHOULD attempt
to notify its administrator, perhaps by emitting a log message.
5. DHCP Server Behavior
The following describes the behavior of a DHCP server that implements
the Client FQDN option when the client's message includes the Client
FQDN option.
The server examines its configuration and the Flag bits in the
client's Client FQDN option to determine how to respond:
o If the client's "E" bit is 0 and the server does not support ASCII
encoding (Section 3.3.1), the server SHOULD ignore the Client FQDN
option.
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o The server sets to 0 the "S", "O", and "N" Flag bits in its copy
of the option it will return to the client. The server copies the
client's "E" bit.
o If the client's "N" bit is 1 and the server's configuration allows
it to honor the client's request for no server initiated DNS
updates, the server sets the "N" bit to 1.
o Otherwise, if the client's "S" bit is 1 and the servers's
configuration allows it to honor the client's request for the
server to initiate A RR DNS updates and if it has the necessary
credentials, the server sets the "S" to 1. If the server's "S"
bit does not match the client's "S" bit, the server sets the "O"
bit to 1.
The server MAY be configured to use the name supplied in the client's
Client FQDN option, or it MAY be configured to modify the supplied
name, or substitute a different name. The server SHOULD send its
notion of the complete FQDN for the client in the Domain Name field.
The server MAY simply copy the Domain Name field from the Client FQDN
option that the client sent to the server. The server MUST use the
same encoding format (ASCII or DNS binary encoding) that the client
used in the Client FQDN option in its DHCPDISCOVER or DHCPREQUEST,
and MUST set the "E" bit in the option's Flags field accordingly.
If a client sends both the Client FQDN and Host Name option, the
server SHOULD ignore the Host Name option.
The server SHOULD set the RCODE1 and RCODE2 fields to 255 before
sending the Client FQDN message to the client in a DHCPOFFER or
DHCPACK.
5.1 When to Perform DNS Updates
The server SHOULD NOT perform any DNS updates if the "N" bit is 1 in
the Flags field of the Client FQDN option in the DHCPACK messages (to
be) sent to the client. However, the server SHOULD delete any RRs
which it previously added via DNS updates for the client.
The server MAY perform the PTR RR DNS update (unless the "N" bit is
1).
The server MAY perform the A RR DNS update if the "S" bit is 1 in the
Flags field of the Client FQDN option in the DHCPACK message (to be)
sent to the client.
The server MAY perform these updates even if the client's DHCPREQUEST
did not carry the Client FQDN option. The server MUST NOT initiate
DNS updates when responding to DHCPDISCOVER messages from a client.
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The server MAY complete its DNS updates (PTR RR or PTR and A RR)
before the server sends the DHCPACK message to the client.
Alternatively, the server MAY send the DHCPACK message to the client
without waiting for the update to be completed. Whether the DNS
update occurs before or after the DHCPACK is sent is entirely up to
the DHCP server's configuration.
If the server's A RR DNS update does not complete until after the
server has replied to the DHCP client, the server's interaction with
the DNS server MAY cause the DHCP server to change the domain name
that it associates with the client. This can occur, for example, if
the server detects and resolves a domain-name conflict [6]. In such
cases, the domain name that the server returns to the DHCP client
would change between two DHCP exchanges.
If the server previously performed DNS updates for the client and the
client's information has not changed, the server MAY skip performing
additional DNS updates.
When a server detects that a lease on an address that the server
leases to a client has expired, the server SHOULD delete any PTR RR
which it added via DNS update. In addition, if the server added an A
RR on the client's behalf, the server SHOULD also delete the A RR.
When a server terminates a lease on an address prior to the lease's
expiration time, for instance by sending a DHCPNAK to a client, the
server SHOULD delete any PTR RR which it associated with the address
via DNS update. In addition, if the server took responsibility for
an A RR, the server SHOULD also delete that A RR.
6. DNS Update Conflicts
This document does not resolve how a DHCP client or server prevent
name conflicts. This document addresses only how a DHCP client and
server negotiate who will perform the DNS updates and the fully
qualified domain name requested or used.
Implementers of this work will need to consider how name conflicts
will be prevented. If a DNS updater needs a security token in order
to successfully perform DNS updates on a specific name, name
conflicts can only occur if multiple clients are given a security
token for that name. Or, if the fully qualified domains are based on
the specific address bound to a client, conflicts SHOULD NOT occur.
Or, a name conflict resolution technique as described in "Resolving
Name Conflicts" [6]) SHOULD be used.
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7. IANA Considerations
IANA has already assigned DHCP option 81 to the Client FQDN option.
As this document updates the option's use, IANA is requested to
reference this document for option 81.
8. Security Considerations
Unauthenticated updates to the DNS can lead to tremendous confusion,
through malicious attack or through inadvertent misconfiguration.
Administrators need to be wary of permitting unsecured DNS updates to
zones which are exposed to the global Internet. Both DHCP clients
and servers should use some form of update request origin
authentication procedure (e.g., Secure DNS Dynamic Update [11]) when
performing DNS updates.
Whether a DHCP client is responsible for updating an FQDN to IP
address mapping or whether this is the responsibility of the DHCP
server is a site-local matter. The choice between the two
alternatives is likely based on the security model that is used with
the DNS update protocol (e.g., only a client may have sufficient
credentials to perform updates to the FQDN to IP address mapping for
its FQDN).
Whether a DHCP server is always responsible for updating the FQDN to
IP address mapping (in addition to updating the IP to FQDN mapping),
regardless of the wishes of an individual DHCP client, is also a
site-local matter. The choice between the two alternatives is likely
based on the security model that is being used with DNS updates. In
cases where a DHCP server is performing DNS updates on behalf of a
client, the DHCP server should be sure of the DNS name to use for the
client, and of the identity of the client.
Currently, it is difficult for DHCP servers to develop much
confidence in the identities of its clients, given the absence of
entity authentication from the DHCP protocol itself. There are many
ways for a DHCP server to develop a DNS name to use for a client, but
only in certain relatively unusual circumstances will the DHCP server
know for certain the identity of the client. If DHCP Authentication
[12] becomes widely deployed this may become more customary.
One example of a situation which offers some extra assurances is one
where the DHCP client is connected to a network through an MCNS cable
modem, and the CMTS (head-end) ensures that MAC address spoofing
simply does not occur. Another example of a configuration that might
be trusted is one where clients obtain network access via a network
access server using PPP. The NAS itself might be obtaining IP
addresses via DHCP, encoding a client identification into the DHCP
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client-id option. In this case, the network access server as well as
the DHCP server might be operating within a trusted environment, in
which case the DHCP server could be configured to trust that the user
authentication and authorization procedure of the remote access
server was sufficient, and would therefore trust the client
identification encoded within the DHCP client-id.
9. Acknowledgements
Many thanks to Mark Beyer, Jim Bound, Ralph Droms, Robert Elz, Peter
Ford, Olafur Gudmundsson, Edie Gunter, Andreas Gustafsson, David W.
Hankins, R. Barr Hibbs, Kim Kinnear, Stuart Kwan, Ted Lemon, Ed
Lewis, Michael Lewis, Josh Littlefield, Michael Patton, Jyrki Soini,
and Glenn Stump for their review and comments.
10. References
10.1 Normative References
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[2] Mockapetris, P., "Domain names - concepts and facilities", STD
13, RFC 1034, November 1987.
[3] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987.
[4] Vixie, P., Thomson, S., Rekhter, Y. and J. Bound, "Dynamic
Updates in the Domain Name System (DNS UPDATE)", RFC 2136, April
1997.
[5] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131,
March 1997.
[6] Stapp, M. and B. Volz, "Resolution of DNS Name Conflicts Among
DHCP Clients (draft-ietf-dhc-ddns-resolution-*.txt)", September
2004.
10.2 Informative References
[7] Marine, A., Reynolds, J. and G. Malkin, "FYI on Questions and
Answers - Answers to Commonly asked "New Internet User"
Questions", RFC 1594, March 1994.
[8] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
Extensions", RFC 2132, March 1997.
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[9] Yergeau, F., "UTF-8, a transformation format of ISO 10646", RFC
2279, January 1998.
[10] Vixie, P., "Extension Mechanisms for DNS (EDNS0)", RFC 2671,
August 1999.
[11] Wellington, B., "Secure Domain Name System (DNS) Dynamic
Update", RFC 3007, November 2000.
[12] Droms, R. and W. Arbaugh, "Authentication for DHCP Messages",
RFC 3118, June 2001.
[13] Lemon, T. and S. Cheshire, "Encoding Long Options in the
Dynamic Host Configuration Protocol (DHCPv4)", RFC 3396,
November 2002.
Authors' Addresses
Mark Stapp
Cisco Systems, Inc.
1414 Massachusetts Ave.
Boxborough, MA 01719
USA
Phone: 978.936.1535
EMail: mjs@cisco.com
Bernie Volz
Cisco Systems, Inc.
1414 Massachusetts Ave.
Boxborough, MA 01719
USA
Phone: 978.936.0382
EMail: volz@cisco.com
Yakov Rekhter
Juniper Networks
1194 North Mathilda Avenue
Sunnyvale, CA 94089
USA
Phone: 408.745.2000
EMail: yakov@juniper.net
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