Some emerging new protocols, notably SOAP (http://www.w3.org/TR/SOAP/) are 
explicitly layered on top of HTTP. A prominently cited reason for this goes 
something like..

  Firewalls usually have port 80 (HTTP) enabled (one way or another), and 
  "most firewalls block non-HTTP requests" [1], so if we layer our new protocol
  abstraction on top of HTTP, we can deploy applications using said protocol  
  and they will just work. 

..with the implication being that such apps will "just work without my having 
to {ask|convince|conjole|coerce} my firewall admin to open new/additional 
ports on our firewall.

So, I'm curious -- what do the firewall admin types on this list think about 
this?

A subtle-but-important point is that as described in [1], the DCOM protocol, 
and ones like it (e.g. DCE-based protocols), dynamically use a range of ports, 
and ~this~ is apparently a big part of the perception that firewall admins are 
reluctant to provide for passage of such protocols across their firewalls.

But, what if a new protocol is cleanly specified on a IANA-assigned well-known 
port (e.g. like LDAP is) -- then is it an issue to the firewall admins to 
incorporate it into their configurations? I.e. if I'm an app-deployer at Foo 
Corp, and I purchase some nifty new stuff that needs to be accessible across 
various security perimeters (defined at least in part by firewalls), and uses 
some new protocol that's legitimately assigned to a well-known port, then is 
this a Big Deal (tm) that I should expect my company's security administrators 
to have a cow over or not? How might the scale and/or purpose of the company's 
network affect this?

Also, there's various discussions of the security considerations involved in 
running effectively new protocols on top of other application-layer protocols 
(read: HTTP, but not limited to it) in [2] and [3]. What do you firewall admin 
types think of the arguments presented therein?

thanks,

JeffH

[1] SOAP: The Simple Object Access Protocol, Aaron Skonnard 
    http://msdn.microsoft.com/library/periodic/period00/soap.htm

[2] SOAP, Bruce Schneier
    http://www.counterpane.com/crypto-gram-0006.html#SOAP

[3] On the use of HTTP as a Substrate for Other Protocols
    http://www.ietf.org/internet-drafts/draft-moore-using-http-01.txt




-
[To unsubscribe, send mail to [EMAIL PROTECTED] with
"unsubscribe firewalls" in the body of the message.]

Reply via email to