Internet DRAFT - draft-zhang-rift-network-ip-assignment

draft-zhang-rift-network-ip-assignment



 



INTERNET-DRAFT                                                  Y. Zhang
Intended Status: Standard Track                                   M. Sun
Expires: September 4, 2018                           Huawei Technologies
                                                                  F. Gao
                                                               Baidu Inc
                                                           March 5, 2018



A method to assign IP-address automatically in data center construction
               draft-zhang-rift-network-ip-assignment-00


Abstract

   IP assignment is always a big challenge in the construction of an
   enterprise-scale data center. For two interfaces connected by a
   cable, if their assigned IP addresses do not belong to a same subnet,
   data then cannot be transmitted via this cable. An error in a cable
   connection could make the IP addresses of the cable's two ends not in
   a same subnet, resulting in a reduction in network throughout.
   Furthermore, it is difficult to find and repair this error connection
   among numerous cables. A method to address this error in switch
   connection would save a great amount of time and cost in modern data
   center construction. Here, this draft introduces an approach to
   assign the IP addresses automatically for two connected switches,
   which allows data to be transmitted via a cable that is connecting
   two arbitrary interfaces from two switches.


Status of this Memo

   This Internet-Draft is submitted to IETF in full conformance with the
   provisions of BCP 78 and BCP 79.

   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 inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/1id-abstracts.html

 


Zhang et at.           Expires September 4, 2018                [Page 1]

INTERNET DRAFT                                             March 5, 2018


   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html


Copyright and License Notice

   Copyright (c) 2018 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
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document. Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.



Table of Contents

   1  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1  Background  . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1  A typical method to assign IPs to interfaces  . . . . . . .  3
   2  IP assigned automatically during switch connection  . . . . . .  4
     2.1 One switch with one logic node . . . . . . . . . . . . . . .  4
     2.2 One switch with more than one logic node . . . . . . . . . .  6
   3  Security Considerations . . . . . . . . . . . . . . . . . . . .  8
   4  References  . . . . . . . . . . . . . . . . . . . . . . . . . .  8
     4.1  Normative References  . . . . . . . . . . . . . . . . . . .  8
     4.2  Informative References  . . . . . . . . . . . . . . . . . .  8
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .  8














 


Zhang et at.           Expires September 4, 2018                [Page 2]

INTERNET DRAFT                                             March 5, 2018


1  Introduction

1.1  Background 

   'Three-layer network' becomes more popular as the scale of a modern
   data center increases continuously. Data can be transmitted in a
   'three-layer network' by using the Border Gateway Protocol (BGP)
   [RFC4271] as the routing protocol [RFC 7938]. For two interfaces
   connected by a cable, if their assigned IP addresses belongs to a
   same subnet, data then can be transmitted via this cable. Otherwise,
   the destination address cannot be resolved via address resolution
   protocol (ARP) [RFC 2119]. This leads to an interruption of BGP,
   which contains the message of allowed data type for switches. As
   there is a strong correlation between switch interfaces and IP
   addresses, a wrong wire connection between the interfaces will result
   in a reduction in the network throughout and even un-reachable for
   some parts of the network.

1.1  A typical method to assign IPs to interfaces

   To avoid a wrong wire connection between two interfaces, a typical
   method is labelling the cable in its two ends during cable
   deployment. As shown in Figure 1, the cable's two ends are attached
   with two labels containing the identifications of local switch and
   interface, and the identifications of peer switch and interface,
   respectively. After the set-up of wire connection, IP addresses
   belong to a same subnet are then assigned to the two connected
   interfaces.

    +--------------------------+          +--------------------------+  
    | Local switch & interface |          | Local switch & interface |  
    | Peer switch & interface  |          | Peer switch & interface  |  
    +--------------------------+          +--------------------------+  
                 \   /                                 \   /            
                  \ /                                   \ /             
                   =======================================

            Figure 1: Attached labels in a cable's two ends.

   This method could effectively reduce the occurrence rate of error
   connection. However, the steps of cable labelling manually and
   insertion into a certain interface, will cost a huge amount of time.
   Furthermore, if there comes an error connection, it is also very
   difficult to find the position of the error connection. 

   This draft presents an approach to assign IP addresses to switch
   interfaces automatically when the interfaces are connected. With this
   approach, message can be transmitted when a cable is connected to the
 


Zhang et at.           Expires September 4, 2018                [Page 3]

INTERNET DRAFT                                             March 5, 2018


   right switch, regardless of the interface it is connected.


2  IP assigned automatically during switch connection

   An innovation of this approach is that IP address is saved on a logic
   node instead of being assigned directly to a certain interface. The
   logic node describes the information of logic IDs of local switch,
   and logic IDs of peer switches, and corresponding IP addresses for
   local interfaces. It is not correlated to a specific interface. Any
   interface of peer switch can be connected to an arbitrary local
   interface. Logic ID could be sent from peer interface to local
   interface by a link layer protocol such as the link-layer discover
   protocol (LLDP) [LLDP]. If the logic ID can be looked up in logic
   nodes, IP address would be assigned to the local interface.

2.1 One switch with one logic node

   Figure 2 illustrates an example of setting up two switches in a
   three-layer network with presented approach. The set-up procedure can
   be divided into four steps as described bellow.

     1)	The two switches are named as LogicID11 and LogicID21,
         respectively. It is worth noting that one switch could be named
         with more than one logic ID (In this case, each switch is named
         with one logic ID). According to the plan of switch connection
         and IP assignment, IP addresses are assigned to some logic
         nodes in switches. The logic node contains the information of
         logic ID of local switch, logic ID of peer switch, and IP
         address for local interface.

     2)	Switches are connected by one cable with little consideration of
         which interface it is used.

     3)	Using a link-layer protocol, the logic ID of local switch is
         sent from the local interface to the peer interface when the
         two switches are wire-connected.

     4)	After receiving the logic ID from peer interface, it will be
         looked up in the logic nodes. The matched logic node will
         assign the corresponding IP address to the local interface.







 


Zhang et at.           Expires September 4, 2018                [Page 4]

INTERNET DRAFT                                             March 5, 2018


      Switch 1                                                          
     +----------------------------------------------------------------+ 
     | +--------------+    +---------------------------------------+  | 
     | | 1) LogicID11 |    | 4) Logic configuration node           |  | 
     | +--------------+    |        local IP IP1                   |  | 
     |                     |        #other configurations          |  | 
     |                     |        peer switch logic id LogicID21 |  | 
     |                     |    quit                               |  | 
     |                     +---------------------------------------+  | 
     +---+------------------------------------------------------------+ 
         |                                   | /|\                      
         |              +-------------------+|  |                       
         |              | 3) Send LogicID11 ||  |                       
         |              +-------------------+|  |                       
         |+---------------------+            |  |                       
         || 2) Cable Connection |            |  |                       
         |+---------------------+            |  |                       
         |                                   |  | +-------------------+ 
         |                                   |  | | 3) Send LogicID21 | 
         |                                   |  | +-------------------+ 
         |                                  \|/ |                       
     +---+------------------------------------------------------------+ 
     | +--------------+    +---------------------------------------+  | 
     | | 1) LogicID21 |    | 4) Logic configuration node           |  | 
     | +--------------+    |        local IP IP2                   |  | 
     |                     |        #other configurations          |  | 
     |                     |        peer switch logic id LogicID11 |  | 
     |                     |    quit                               |  | 
     |                     +---------------------------------------+  | 
     +----------------------------------------------------------------+ 
      Switch 2

    Figure 2: Schematic diagram of the approach for auto-assignment
                   of IP addresses for wired switches.


   This approach utilizes a link layer protocol to send the logic ID of
   local switch to peer switch. For an example of using LLDP, the LLDP
   frame not only contains the mandatory type-length-value (TLV)
   structures of Chassis ID, Port ID, Time-to-live and End of LLDPDU,
   but also contains a TLV structure of Logic ID as follows [TLV-type]:

  +----+----+-------+---------+------+-----+-------+----------+--------+
  | DA | SA | Ether | Chassis | Port | TTL | Logic | Optional | End of |
  |    |    | Type  | ID      | ID   |     | ID    | TLVs     | LLDPDU |
  +----+----+-------+---------+------+-----+-------+----------+--------+


 


Zhang et at.           Expires September 4, 2018                [Page 5]

INTERNET DRAFT                                             March 5, 2018


2.2 One switch with more than one logic node

     Switch 1    /                   /       /                          
    +----------- \ ----------------- \ -...- \ ---------------------+   
    |            /                   /       /                      |   
    | LogicID11  \  LogicID12        \       \  LogicID1x           |   
    |            /                   /       /                      |   
    |            \                   \       \                      |   
    |            /                   /       /                      |   
    |            \                   \       \                      |   
    |            /                   /       /                      |   
    |            \                   \       \                      |   
    |            /                   /       /                      |   
    |  1    2    \    3    4    5    \       \                      |   
    +-+-+--+-+-- / --+-+--+-+--+-+-- / -...- / --+-+--+-+--+-+--+-+-+   
      +++  +++   \   +-+  +-+  +-+   \       \   +-+  +-+  +-+  +-+     
       |     \                                                          
       |      \                                                         
       |       \                                                        
       |        \                                                       
     a |       b \                                                      
       |          \                                                     
       |           \                                                    
       |            \                                                   
       |             \                                                  
      +++  +-+   /   +++  +-+  +-+   /       /   +-+  +-+  +-+  +-+     
    +-+-+--+-+-- \ --+-+--+-+--+-+-- \ -...- \ --+-+--+-+--+-+--+-+-+   
    |  1    2    /    3    4    5    /       /                      |   
    |            \                   \       \                      |   
    | LogicID21  /  LogicID22        /       /  LogicID2x           |   
    |            \                   \       \                      |   
    |            /                   /       /                      |   
    |            \                   \       \                      |   
    |            /                   /       /                      |   
    |            \                   \       \                      |   
    |            /                   /       /                      |   
    |            \                   \       \                      |   
    +----------- / ----------------- / -...- / ---------------------+   
     Switch 2    \                   \       \

Figure 3: In an case of one switch is named with more than one logic ID.

   Figure 3 presents the case in which one switch are named with more
   than one logic ID. For example, in Switch 1, Interface 1 and 2 belong
   to LogicID11, while Interface 3, 4 and 5 belong to LogicID12. Two
   cables marked as 'a' and 'b' connect the Interface 1 of Switch 1 to
   Interface 1 of Switch 2, and Interface 2 of Switch 1 to Interface 3
   of Switch 2, respectively. After connection, logic ID of local switch
 


Zhang et at.           Expires September 4, 2018                [Page 6]

INTERNET DRAFT                                             March 5, 2018


   will be sent to peer switch. Then, the logic ID of peer switch,
   together with the logic ID of local switch, will be looked up in
   logic nodes. As shown in Table 1, IP address of 182.111.211.111
   255.255.255.0 will be assigned to Interface 1 of Switch 1, while IP
   address of 182.111.222.111. 255.255.255.0 will be assigned to
   Interface 2 of Switch 1. An advantage of this approach is that
   correct IP address still can be assigned to local interface when an
   error connection between interfaces occurs. For example, when
   Interface 2, instead of Interface 1 of Switch 2 is connected to
   Interface 1 of Switch 1, IP address of 182.111.211.111 255.255.255.0
   will also be assigned to Interface 1 of Switch 1. In that case, data
   still can be transmitted by cable 'a' without any problem in ARP.
   Furthermore, when Switch 2 is replaced by another one Switch 3 in the
   future, IP address will also be assigned to local and peer interfaces
   automatically if there are 'Switch 3'-related logic IDs in nodes.


         Table 1: List of Logic nodes For Switch 1 in Figure 3.

   ---------------------------------------------------------------------
   Logic id of   Logic id of   Interface configuration                 
   local switch  peer switch                                           
   ---------------------------------------------------------------------
       11            21        undo portswitch                          
                               ip address 182.111.221.111 255.255.255.0

       11            22        undo portswitch                          
                               ip address 182.111.222.111 255.255.255.0

       12            21        undo portswitch                          
                               ip address 182.111.221.112 255.255.255.0

       12            22        undo portswitch                          
                               ip address 182.111.222.112 255.255.255.0

       ......

   ---------------------------------------------------------------------


   Compared with conventional IP assignment method, this method assigns
   the IP addresses automatically for wired switches, which can
   significantly decrease the workload of cable deployment. Cable will
   not be required to connect to a specific interface, leading to a
   reduction in both working time and rate of error connection. When
   cable is changed from one interface to another one belonging to a
   same switch logic ID, network will work as normal without any
   necessary in changing setting. 
 


Zhang et at.           Expires September 4, 2018                [Page 7]

INTERNET DRAFT                                             March 5, 2018


3  Security Considerations

   The design does not introduce any additional security concerns.
   General BGP security considerations are discussed in [RFC4271] and
   [RFC4272].

4  References

4.1  Normative References

   [RFC4271]  Y. Rekhter, T. Li, and S. Hares, "A Border Gateway
              Protocol 4 (BGP-4)", RFC 4271, January 2006.

   [LLDP]     IEEE, "IEEE Standard for Local and metropolitan area
              networks station and Media Access Control Connectivity
              Discovery Corrigendum 2: Technical and Editorial
              Corrections", IEEE 802.1AB-2009/Cor 2-2015, DOI
              10.1109/ieeestd.2015.7056401, March 2015.

4.2  Informative References

   [RFC7938]  P. Lapukhov, A. Premji, and J. Mitchell, "BGP Routing in
              Data Centers", RFC 7938, August 2016.

   [RFC2119]  S. Bradner, "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [TLV-type] IEEE Std 802.AB-2016, DOI:  10.1109/IEEESTD.2016.7433915,
              March 2016,
              <http://ieeexplore.ieee.org/servlet/opac?punumber=7433913>

   [RFC4272]  S. Murphy, "BGP Security Vulnerabilities Analysis", RFC
              4272, January 2006.

Authors' Addresses

   Yun Zhang
   Huawei
   101 Software Avenue, 
   Yuhuatai District, Nanjing, 210012
   China

   EMail: zhangyun45@huawei.com





 


Zhang et at.           Expires September 4, 2018                [Page 8]

INTERNET DRAFT                                             March 5, 2018


   Marcus Sun
   Huawei
   101 Software Avenue, 
   Yuhuatai District, Nanjing, 210012
   China

   EMail: marcus.sun@huawei.com


   Feng Gao
   BAIDU Inc.
   10 shangdi shijie Haidian, Beijing
   China

   Email:gaofeng04@baidu.com




































Zhang et at.           Expires September 4, 2018                [Page 9]