Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.

IPNBK

Prolog  

Control Block Contents  
   IPNBK DSECT
   IPNXM DSECT
   IPNMC DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  


IPNBK Prolog

 NAME       : HCPIPNBK
 DESCRIPTION: IP Node block
 DSECT      : IPNBK
 FUNCTION   :
              The IPNBK structure defines a relationship between
              a specific IP Address and a specific network device
              (represented by a NIDBK).  When a device is subscribed
              to an IP Address, the IPNBK can be found by looking up
              the IP Address in the LAN IP Table or by following the
              subscription chain anchored within the NIDBK (NIDIPNHD).
 LOCATED BY -
   LANIPTBL - Pointer to multi-level indexed IP Table.
   NIDIPNHD - Anchor for the NIDBK subscription chain.
 CREATED BY :
              IP Address functions in module HCPIPN.
 DELETED BY :
              IP Address functions in module HCPIPN.
 NOTES      :
              (1) The IPNBK is imbedded within an IPNMC block
              when it represents the device subscription
              to a Multicast IP Address.  The IPNMC blocks
              for a single Multicast IP Address are all
              chained together in a Multicast subscription
              list anchored in the IPNXM block.
              (2) The IPNBK is imbedded within an IPNXM block
              when it represents the LAN IP Table reference
              for a Multicast IP Address.  The IPNXM block
              is found via the IP Address, and it acts as
              the anchor for the individual device IPNMC
              subscriptions.

 

IPNBK Control Block Content


IPNBK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      IPNBK          IP Node block
     IP Table Node (for an IP Unicast/Multicast entry).
0000    0 Character    1 IPNTYPE        IPNBK Type
          000000E4       IPNTYPUC       C'U' Unicast IPNBK (Registration)
          000000E7       IPNTYPXM       C'X' Multicast IPNXM (Header)
          000000D4       IPNTYPMC       C'M' Multicast IPNMC
                                        (Subscription)
0001    1 Bitstring    5 *              Reserved
0006    6 Bitstring    2 IPNOSID        OSID value
0008    8 Address      4 IPNFPNT        Pointer to next IPNBK
000C   12 Address      4 IPNBPNT        Pointer to previous IPNBK
0010   16 Bitstring    4 IPNADDR        IP Address (4 bytes)
0014   20 Address      4 IPNLINK        Pointer to associated device
     End of the IPNBK.
0018   24 Dbl-Word     8 IPN$END (0)    End of the IPNBK structure
          00000018       IPNBKLN        *-IPNBK Length of IPNBK in bytes
          00000003       IPNBKSZ        (*-IPNBK+7)/8 Size of IPNBK in
                                        doublewords
     IPNXM structure -
     The IPNXM is an extended IPNBK.
     Each IPNXM represents a chain of IPNMC entries. For an IP Address in
     the IP Multicast range, the LAN IP Table points to an IPNXM (instead of
     an IPNBK). The IPNXM contains the anchor for the chain of subscribed
     devices (each represented by an IPNMC).

IPNXM DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      IPNXM          IP Node block
0000    0 Dbl-Word     8 IPNXMNOD (3)   Space for IPNBK entry
0018   24 Address      4 IPNXMLST       Pointer to first IPNMC in chain
001C   28 Signed       4 IPNXMCTR       Number of subscribed devices
          00000020       IPNXMLN        *-IPNXM Length of IPNXM in bytes
          00000004       IPNXMSZ        (*-IPNXM+7)/8 Size of IPNXM in
                                        doublewords
     IPNMC structure -
     The IPNMC is an extended IPNBK.
     Each IPNMC represents an IP Multicast subscriber. When you lookup an IP
     Multicast address in the LAN IP Table, it points to the first entry in
     a linked list of IPNMC structures. The imbedded IPNMC is chained with
     others belonging to the same Device (NIDBK).

IPNMC DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      IPNMC          IP Node block
0000    0 Dbl-Word     8 IPNMCNOD (3)   Space for standard IPNBK entry
0018   24 Character   10 IPNMCKEY (0)   Unique identifier for IPM entry
0018   24 Character    8 IPNMCUSR       IPNMCKEY Userid
0020   32 Character    2 IPNMCDEV       IPNMCKEY virtual device number
0022   34 Bitstring    6 IPNMCMAC       MACADDR subscribed to this IP
0028   40 Address      4 IPNMCNXT       Pointer to next IPNMC
002C   44 Address      4 IPNMCHDR       Pointer to primary IPNXM
          00000030       IPNMCLN        *-IPNMC Length of IPNMC in bytes
          00000006       IPNMCSZ        (*-IPNMC+7)/8 Size of IPNMC in
                                        doublewords
     IP Multicast Address (IPM) indicator. When the IP Address byte 0 is in
     the range of 224-239 (x'E0'-x'EF') it designates an IP Multicast
     address. To determine if an IP Address is an IPM Address: (1) TM
     byte0,IPNMCON; If cc<3 it is NOT an IPM (2) TM byte0,IPNMCOFF; If
     cc>0 it is NOT an IPM The address must pass BOTH tests to be
     accepted as a Multicast IP Address.
          1111 ....      IPNMCMSK       X'F0' IPM Byte 0 - Significant
                                        bits
          111. ....      IPNMCON        X'E0' IPM Byte 0 - These bits are
                                        ON
          ...1 ....      IPNMCOFF       X'10' IPM Byte 0 - These bits are
                                        OFF

 

IPNBK Storage Layout

          
*** IPNBK - IP Node block
*
*     +------+----------------------------------+-------------+
*   0 |:TYPE |//////////////////////////////////|  IPNOSID    |
*     +------+--------------------+-------------+-------------+
*   8 |         IPNFPNT           |         IPNBPNT           |
*     +---------------------------+---------------------------+
*  10 |         IPNADDR           |         IPNLINK           |
*     +---------------------------+---------------------------+
*
*** IPNBK - IP Node block
          
*** IPNXM - IP Node block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       IPNXMNOD                        =
*     |                                                       |
*     +---------------------------+---------------------------+
*  18 |         IPNXMLST          |         IPNXMCTR          |
*     +---------------------------+---------------------------+
*  20
*
*** IPNXM - IP Node block
          
*** IPNMC - IP Node block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       IPNMCNOD                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  18 |                       IPNMCUSR                        |
*     +-------------+-----------------------------------------+
*  20 |  IPNMCDEV   |                IPNMCMAC                 |
*     +-------------+-------------+---------------------------+
*  28 |         IPNMCNXT          |         IPNMCHDR          |
*     +---------------------------+---------------------------+
*  30
*
*** IPNMC - IP Node block

 

IPNBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
IPN$END        0018
IPNADDR        0010
IPNBKLN        0018 00000018
IPNBKSZ        0018 00000003
IPNBPNT        000C
IPNFPNT        0008
IPNLINK        0014
IPNMCDEV       0020
IPNMCHDR       002C
IPNMCKEY       0018
IPNMCLN        002C 00000030
IPNMCMAC       0022
IPNMCMSK       002C F0
IPNMCNOD       0000
IPNMCNXT       0028
IPNMCOFF       002C 10
IPNMCON        002C E0
IPNMCSZ        002C 00000006
IPNMCUSR       0018
IPNOSID        0006
IPNTYPE        0000
IPNTYPMC       0000 000000D4
IPNTYPUC       0000 000000E4
IPNTYPXM       0000 000000E7
IPNXMCTR       001C
IPNXMLN        001C 00000020
IPNXMLST       0018
IPNXMNOD       0000
IPNXMSZ        001C 00000004

This information is based on z/VM V4R3.0. Last updated on 30 Apr 2002 at 16:39:27 EDT.
Copyright IBM Corporation, 1990, 2002