Subject: Query on syntax of Hostname

From: [email-masked]
Date: Wed, 14 Apr 2004 08:10:45 +0100

In Section 3.3.2.1 Host Name Address it states:

This field contains a host name in "host name syntax" per RFC 1123 Section 2.1.

RFC 1123 Section 2.1 refers to RFC 952 which states:

   A "name" (Net, Host, Gateway, or Domain name) is a text string up
   to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus
   sign (-), and period (.).  Note that periods are only allowed when
   they serve to delimit components of "domain style names". 

RFC 1123 later refers to RFC 1035 which states:

Domain names in messages are expressed in terms of a sequence of labels.
Each label is represented as a one octet length field followed by that
number of octets. 

So, which syntax is used in SCTP messages?

Thanks,
Joyce

---

From: "Randall Stewart (cisco)" <[email-masked]>
Date: Wed, 14 Apr 2004 08:46:22 -0500

Joyce:

two relevant items..

a) It was always meant to be a string of characters as described in 
2.1//RFC1123.
    We did not have any intention on it being a DNS name or a NIS name 
or whatever...

b) So far we have not found anyone that supports this feature in kernel land
    code for sure.. and in most implementations.. it has not been able to
    be tested at any bakeoff... The problem is with what is envolved if
    you are writting a kernel call that does an upcall to the app level
    to get a DNS name that does kernel calls down while the kernel waits
    for the app to get back to it.. it becomes VERY VERY ugly and I doubt
    that any kernel implementation of SCTP will bother implementing that
    feature.. more likely it will be like KAME or Linux lk-sctp do.. i.e. a
    supported address type is always sent out with V4/V6 in it... and
    if you send me a host name address I will abort you with a
    unresolvable address error...

R

-- 
Randall R. Stewart
ITD - Transport Technologies
815-477-2127(o) or 815-342-5222(c)