*BSD News Article 33974


Return to BSD News archive

Newsgroups: comp.os.386bsd.questions
Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!msuinfo!agate!library.ucla.edu!csulb.edu!nic-nac.CSU.net!usc!cs.utexas.edu!convex!seas.smu.edu!rwsys!hammy!gordon
From: gordon@sneaky.lonestar.org (Gordon Burditt)
Subject: Re: PPP
References: <30n5qj$3s1@portal.gmu.edu> <michaelv.774892571@ponderous.cc.iastate.edu>
Organization: /usr/lib/news/organi[sz]ation
Date: Thu, 4 Aug 1994 18:31:45 GMT
Message-ID: <Cu0wsy.ExG@sneaky.lonestar.org>
Lines: 51

Is there a way to get fully automatic PPP?  I may be asking for the moon
here, but I'd like to be able to set up PPP so that the connection
is established and disconnected as needed.

- Routing is set up when the system is booted without necessarily needing
  to set the link up at this point.  Daemons get started as needed.
- The PPP connection is established when needed for useful traffic by 
  dialing an internet services provider and logging in.  Provision is
  made to try alternate numbers.
- The PPP connection is disconnected after a user-configurable period
  of time (e.g. a few minutes) with no useful traffic.
- Traffic can be classified by user configuration into three types, 
  "useful", which calls for establishing or keeping established a PPP 
  link, "non-useful", which is allowed when the link is up already but
  is not cause for establishing the link and gets dropped if the link is
  down, and "forbidden", which is not allowed on the PPP link at all.
- Examples of "non-useful" traffic include broadcast messages, NTP, rwho,
  and other stuff I haven't thought of that would generate periodic traffic
  and keep the link up all the time without accomplishing much.
- Examples of "useful" traffic include SMTP, ftp, NNTP, nameserver queries, 
  telnet, and most other services.
- Examples of "forbidden" traffic would mostly depend on the security
  environment, and might include incoming telnet, incoming ftp, etc.

- It should be possible to disconnect the link while keeping logical
  connections alive.  For example, I nfs-mount a server's file system
  read-only, copy a few files to a local disk, start compiling them 
  (which no longer requires the remote file system), the link times out 
  and disconnects.  An hour later I discover I forgot a few files, start 
  copying them and the link comes up again (no remount required).  I
  ftp to another site and start a big transfer, then go to lunch.  The
  link drops when the transfer is done, but leaves the ftp session up.
  (Yes, I know hogging ftp sessions is anti-social if done for a long time.)

- When the link isn't being used for PPP, it can be used for outgoing
  UUCP or tip, incoming UUCP, or incoming PPP from the service provider
  if the provider is willing to do that.  If the link's not available
  when needed, the packets get dropped and whatever sent them times
  out eventually.

How much of a pipe dream is this?  Is establishing a ftp session going to
be possible if the first packet sent through (bringing the link up)
takes a minute to transmit?  Are TCP "keepalives" going to keep the link
up all the time anyway?

In what areas does the existing PPP implementation (pick your favorite
platform:  FreeBSD, NetBSD, Linux) fall short of what I want, and
is it possible (with lots of work, probably) to add it?

						Gordon L. Burditt
						sneaky.lonestar.org!gordon