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[ale] Comcast linux...
speaking as someone with about 200 servers to worry about: IPv6
*shudder*. If the network goons around here understood the term "phased
rollout", maybe I'd be less scared.
No, I wasn't questioning TCP per se, but pointing out that its not
always the best tool for the job. Sometimes a nice hammer is overkill,
when a good rock will do ;).
Truth is, most "native" UDP apps' modern incarnations also work just
fine (er at least mostly fine) using TCP, since for most things, its
what's in the packets/datagrams that matter anyway. However, as Bob
pointed out, there can be a performance impact (and as Chris just
pointed out, who cares if the app is broadcast based anyway).
One good modern example of TCP connection assurance vs. UDP efficiency
can be seen in the most cutting edge of programming challenges: network
gaming. Most of the modern FPS engines, for instance, use UDP to send
updates from server to client. In many respects, this is the only way
for clients to keep up without lag, and if the client has to ask for a
packet to be retransmitted, its likely that the data in that packet is
already outdated, so why bother?
Berlin Brown wrote:
> I hope you are not questioning tcp. I have never really thought about
> the overhead or the implications whether udp or tcp is out dated. But,
> imagine the overhaul in changing applications to some newer protocol.
> Plus, is ipv6 tcp better than ipv4. It looks like it is easy to enable
> on my freebsd system, but scared to.
> And then again, what is Internet 2?
> */Mike Murphy <mike at tyderia.net>/* wrote:
> DHCP grew from BootP, which is also a UDP protocol. If memory serves,
> BootP is UDP because that's mostly how such LAN utility protocols were
> done, way back when. UDP is probably the better choice anyway, at least
> from an efficiency point of view, anyway. DNS, NFS, and a host of other
> "early" protocols were all UDP based, at least initially, for similar
> reasons. After all, who want's all that extra overhead of SYN'ing and
> ACK'ing when you can just spew datagrams if you want to get an SPX
> connection for your printer?
> Bob Toxen wrote:
> > On Tue, Jan 06, 2004 at 09:36:57AM -0500, Yu, Jerry wrote:
> >>I have a RH linux hooked up to the cable modem (Motorolla
> surfboard ??4100).
> >>It always picks up IP/subnet/dns using DHCP just fine. The RH has
> >>upgraded from RH 6.1 all the way to 9.0. Hasn't got around to
> upgrade to
> >>Fedora yet.
> >>Make sure your firewall rules allows DHCP (67/68).
> >>I can give you the information once I get home. However, the IP
> you grab
> >>manually may conflicts with whoever gets assigned by Comcast's DHCP
> > Actually, you probably do NOT need to enable DHCP (UDP 67/68) in your
> > firewall as dhclient (and almost certainly the other DHCP
> clients) put
> > the interface in Promiscuous mode to listen. They need to do this
> > otherwise the hardware will filter out DHCP packets as having
> someone else's
> > IP address as the destination. Do "ifconfig" and look for the
> > flag (unless you have one of the versions of RH that have a
> broken version
> > of ifconfig, in which case the script that ships with my book
> will tell.)
> > Yet another reason why DHCP is a badly designed protocol. Who
> created it
> > anyway? The other reason is that it is UDP which is spoofable,
> rather than
> > TCP which is not with a decent stack. Microsoft?
> > Bob
> >>-----Original Message-----
> >>From: Byron A Jeff [mailto:byron at cc.gatech.edu]
> >>Sent: Tuesday, January 06, 2004 7:26 AM
> >>To: Atlanta Linux Enthusiasts
> >>Subject: Re: [ale] Comcast linux...
> >>On Mon, Jan 05, 2004 at 03:20:48PM -0800, Berlin Brown wrote:
> >>>I almost have my comcast cable modem setup. I think I just need
> a primary
> >>>dns, nameserver using ips only. Does anybody have the dns for
> >>>comcast, emory area.
> >>That's an interesting question. Everything for comcast is set up
> via DHCP
> >>>I cant find it on the net. And the people at comcast wont give
> it to me.
> >>>Redhat is supposed to pick it up, but it didnt?
> >>That's real interesting. Actually it just got more interesting as
> I checked
> >>my smoothwall machine and it's acting as its own caching
> nameserver. So
> >>I don't have the address either.
> >>BTW the cc.gatech.edu College of Computing server will serve DNS
> >>to anyone who asks. It's what I always use when I don't know the
> >>address: 18.104.22.168
> >>>Funny thing, when the comcast tech came. At first I never even
> >>>needed a windows machine(havent installed a win machine in 2 years).
> >>>the guy went nuts over it.
> >>Not only typical, but it's in your Terms of Service.
> >>> I said fine, just leave the modem, 'We can't do
> >>>that, once you get windows up, we will send another guy out.'
> >>Again the standard response.
> >>>B.S.!, just leave the modem, Ill figure it out, then he left.
> >>It's unfair, but makes sense. Here's the facts of the matter:
> >>1) The techs only have limited training.
> >>2) The customers generally know nothing about computers and
> >> this gives the techs an advantage, until they come across one of
> us. ;-)
> >>3) It costs money to train for another OS and....
> >>4) They can lose their jobs if they leave without it being set up.
> >>It's a tough life for us Linux folks, but in fact I and
> appreciate the
> >>policy because if they did train the Techs (both rolling and phone),
> >>the cost of service goes up.
> > The service does not go up. The $600 a year that one Linux user
> > is more enough to add two lines to the script that the Techs use.
> >>On the phone I always tell 1st level tech support that's it's a
> Windows 2000
> >>box. I patiently explain that it's the cable modem, not my
> machine. If I
> >>get to second level I ask "Do you want to hear the truth?".
> Usually they do,
> >>but they don't flip out. I ask them what they are looking for and
> > Yes, the only way I got the MediaMinusOne (that became ComCast)
> morons to
> > verify that they miskeyed my MAC address (despite my handing them
> a printed
> > copy) was by lying and saying that I hat Windoze95.
> >>I still find it interesting that no DNS info comes through...
> > _______________________________________________
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> > Ale at ale.org
> > http://www.ale.org/mailman/listinfo/ale
> Mike Murphy
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