IP4HDR Back to Index page
 
Prolog 
Control Block Contents 
   IP4HDR DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.

 
  IP4HDR Control Block Content Top of page
 

 IP4HDR DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IP4HDR IP (Internet Protocol) Header IP Header for IPv4 (ETHTYPE = x'0800'). 0000 0 Bitstring 1 IP4VER +00 IP Version || header length 00000045 IP4VHDRL X'45' IP4VHDRL - IPv4 and header length of 5 0001 1 Bitstring 1 IP4TOS +01 Type of service 0002 2 Bitstring 2 IP4TOTLN +02 Total Length 0004 4 Bitstring 2 IP4ID +04 Identification 0006 6 Signed 2 IP4FIELD (0) Flags (3 bits || Frag 13 bits) 0006 6 Bitstring 1 IP4FLAGS +06 Flags (Bits 0,1,2) 00000040 IP4DF X'40' IP4DF - Pv4 "Don't Fragment Flag 0007 7 Bitstring 1 * +07 Fragment offset (partial) 0008 8 Bitstring 1 IP4TTL +08 TTL Counter 0009 9 Bitstring 1 IP4PROT +09 Protocol 00000001 IP4ICMP 1 IP4ICMP - ICMP 00000002 IP4IGMP 2 IP4IGMP - IGMP 00000006 IP4TCP 6 IP4TCP - TCP 00000011 IP4UDP 17 IP4UDP - UDP 000A 10 Bitstring 2 IP4CKSUM +0A IP Header only Checksum 000C 12 Bitstring 4 IP4SRC +0C IPv4 Source Address 0010 16 Bitstring 4 IP4DEST +10 IPv4 Destination Address 00000014 IP4NEXT * +14 Start of next element 00000014 IP4LENTH *-IP4HDR Length of IPv4 header in bytes 00000007 IP4ICPWD (IP4LENTH+8)/4 IPv4 ICMP payload in words 0000001C IP4ICPBT (IP4LENTH+8) IPv4 ICMP payload in bytes IPv6 - Internet Protocol Header
 
 
  IP4HDR Storage Layout Top of page
 
          
*** IP4HDR - IP (Internet Protocol) Header
*
*     +------+------+-------------+-------------+------+------+
*   0 |IP4VER|IP4TOS|  IP4TOTLN   |   IP4ID     |:FLAGS|//////|
*     +------+------+-------------+-------------+------+------+
*   8 |IP4TTL|:PROT |  IP4CKSUM   |          IP4SRC           |
*     +------+------+-------------+---------------------------+
*  10 |         IP4DEST           | 14
*     +---------------------------+
*
*** IP4HDR - IP (Internet Protocol) Header
 
 
  IP4HDR Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
IP4CKSUM       000A
IP4DEST        0010
IP4DF          0006 00000040
IP4FIELD       0006
IP4FLAGS       0006
IP4ICMP        0009 00000001
IP4ICPBT       0010 0000001C
IP4ICPWD       0010 00000007
IP4ID          0004
IP4IGMP        0009 00000002
IP4LENTH       0010 00000014
IP4NEXT        0010 00000014
IP4PROT        0009
IP4SRC         000C
IP4TCP         0009 00000006
IP4TOS         0001
IP4TOTLN       0002
IP4TTL         0008
IP4UDP         0009 00000011
IP4VER         0000
IP4VHDRL       0000 00000045
 
This information is based on z/VM 7.3.0 Last updated on 22 Jun 2022 at 15:51:36 EDT.
Copyright IBM Corporation, 1990, 2022