From: tld5032@bcstec.ca.boeing.com (Terry Davis)
Subject: Use of DNS to support SNA over TCPIP
Organization: Boeing
Date: Wed, 27 Jan 1993 20:26:13 GMT


In recent months, there has been a flurry of activity discussing the
implementations by CISCO and IBM providing for SNA transport via TCPIP.
To support this architecture, some method of providing SNA to TCPIP
address correlation is required.  Attached is a sample of a working
zone implementation to do this.  It requires no code changes and should
be supportable in most DNS implementation.

The concept is simply to provide an SNA zone for your domain.  This zone
is made up of entirely CNAME records.  These allow the LU/NETID SNA address
pairs to be mapped to a TCPIP hostname.  A few lines of code can then be
hacked together using standard "gethostbyname" functions to retrieve the
TCPIP address associated with the LU/NETID SNA address.  The "gethostby-
name" call requests the host address for "LU.NETID.SNA.COMPANY.COM.".
DNS does the lookup for the host named "LU.NETID", finding a CNAME record
it then recurses to the nameserver of the TCPIP hostname, and returns
the TCPIP hostname and IP address in the standard structures.

This may or may not be an appropriate implementation for the long term
since it lacks the ability to provide reverse translations.  For initial
development, though, this meets most requirements since SNA applications
generally being converted for use over TCPIP require the application to
have only knowledge of the SNA address it wishes to connect to and do not
at present have use for the concept of reverse translation.  In the long
run, this may be a serious deficiency for both security and network
management.

Forgive the re-formating, but by necessity all addresses, names, and
LU/NETID's in the template had to be generic, not real.


Comments, criticisms, and flames desired!  I read namedroppers, and 
"comp.protocols.tcp-ip.domains" and will respond to posts in either.
You may also reply directly to the INTERNET address in the signature
block if you desire.



Take care

 | Terry L. Davis | Boeing Computer Services, Bellevue, WA         |
 |  206-957-5325  | BOEING EMAIL: tld5032@commanche.ca.boeing.com. |
 | INTERNET EMAIL: tld5032@atc.boeing.com.                         |
  -------------- Wednesday January 27,1993 12:05 PM PST ------------- 
 == As always, should the above be construed as representing BOEING, ==
 ==   the COMPANY will dis-avow any knowledge of me or my actions.   ==













=======================================================================
;  
; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^  
;  named.sna  
;  
;  DOMAIN:  sna.your_company.com.
;  
; 
sna.your_company.com. IN SOA dns_svr.your_company.com. mailid.dns_svr.your_company.com. (
            92121701          ; Serial       
            7200              ; Refresh         
            900               ; Retry           
            604800            ; Expire          
            86400 )           ; Minimum         
;
                              IN        NS     dns_svr.your_company.com. 
dns_svr.your_company.com.     IN        A       1xx.4x.137.37
                              IN        A       1xx.1xx.25.17
;                             IN        A       1xx.4x.122.18
;                             IN        A       1xx.1xx.21.92
;
$ORIGIN sna.your_company.com.
;
MF1162P0.YNID                      IN   CNAME     ibm_mf_1.your_company.com.
MF1162P1.YNID                      IN   CNAME     ibm_mf_1.your_company.com.
MF1162P2.YNID                      IN   CNAME     ibm_mf_1.your_company.com.
MF1162PB.YNID                      IN   CNAME     ibm_mf_1.your_company.com.
TSTC62P0.YNID                      IN   CNAME     ibm_mf_1.your_company.com.
TSTC62P1.YNID                      IN   CNAME     ibm_mf_1.your_company.com.
TSTC62P2.YNID                      IN   CNAME     ibm_mf_1.your_company.com.
TSTC62PB.YNID                      IN   CNAME     ibm_mf_1.your_company.com.
MF11AIRW.YNID                      IN   CNAME     ibm_mf_1.your_company.com.
MF11TSTC.YNID                      IN   CNAME     ibm_mf_1.your_company.com.
MF11TST0.YNID                      IN   CNAME     ibm_mf_1.your_company.com.
;

MF2T62P0.YNID                      IN   CNAME     ibm_mf_2.your_company.com.
MF2T62P1.YNID                      IN   CNAME     ibm_mf_2.your_company.com.
MF2T62P2.YNID                      IN   CNAME     ibm_mf_2.your_company.com.
MF2T62PB.YNID                      IN   CNAME     ibm_mf_2.your_company.com.
AIRWTEST.YNID                      IN   CNAME     ibm_mf_2.your_company.com.
;
E372411.YNID                       IN   CNAME     ibm_rs_1.your_company.com.
E372411A.YNID                      IN   CNAME     ibm_rs_1.your_company.com.
E383245.YNID                       IN   CNAME     ibm_rs_2.your_company.com.
E383245A.YNID                      IN   CNAME     ibm_rs_2.your_company.com.
;
NDNSSVR0.YNID                      IN   CNAME     dns_svr.your_company.com.
NSUNWS10.YNID                      IN   CNAME     sun_ws_1.your_company.com.
NSUNWS00.YNID                      IN   CNAME     sun_ws_2.your_company.com.
NIBMMF30.YNID                      IN   CNAME     ibm_mf_3.your_company.com.
;
OS2PC905.YNID                      IN   CNAME     os2_9m5.your_company.com.
;
OS2PC204.YNID                      IN   CNAME     os2_2m4.your_company.com.
OS2PC214.YNID                      IN   CNAME     os2_2m4.your_company.com.
OS2PC404.YNID                      IN   CNAME     os2_4m4.your_company.com.
OS2PC414.YNID                      IN   CNAME     os2_4m4.your_company.com.
OS2PC504.YNID                      IN   CNAME     os2_5m4.your_company.com.
OS2PC514.YNID                      IN   CNAME     os2_5m4.your_company.com.
OS2PC604.YNID                      IN   CNAME     os2_6m4.your_company.com.
OS2PC614.YNID                      IN   CNAME     os2_6m4.your_company.com.
OS2PC904.YNID                      IN   CNAME     os2_9m4.your_company.com.
OS2PC914.YNID                      IN   CNAME     os2_9m4.your_company.com.
;