Re: Renumbering

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sep 13, 2007, at 23:42 , Keith Moore wrote:

Disconnect current session, reconnect.
Uh, not unless your application has some sort of retry or
checkpoint-restart capability. SMTP is pretty resilient in the face of connection breakage, and for some interactive applications you just hit
"retry" or the equivalent, which has caused some people to think that
somehow it's okay if the network changes a host's IP addresses out from
under it.  But it doesn't work in general.
I think the way IPv6 handles this by deprecating the current address  
but keeping it alive for some time is entirely reasonable. So if  
you're doing a large file transfer or something like that, you can  
finish it, then disconnect and reconnect using the new address.
Assuming that you can keep a session alive for weeks or months  
without the ability to recover from disconnects is not a smart idea,  
to say the least.
This falls under the heading of "nobody is stopping us from doing this and it works today so now it's a feature and it can never be taken away".
No, it just means that people shouldn't assume that existing DNS names
(i.e. the ones we're already using to identify hosts and services) will
work as endpoint identifiers for the purpose of connection restart.
Huh?

What ARE DNS names good for, if not that?

Obviously if people put a bunch of hosts in the DNS under a common service name, the idea is that all of the hosts provide the service in question.
I also don't feel responsible for keeping the host/service  
distinction. If a certain protocol needs to talk to individual hosts  
and not services, then the people creating DNS names for use with  
that protocol should take that into account and not whine.
People are using DNS names to name things that aren't hosts (e.g.
services or groups of hosts) for valid reasons and any solution that
destroyed this functionality would be a non-starter.
Like I said, EVERYTHING is a non-starter today so we don't start  
anything anymore. The assumption that everything that works today  
will continue to work forever is broken.
That's the least of the problems with renumbering.  A few years ago I
was involved in renumbering of a class B IPv4 network.  DHCP and DNS
doesn't even begin to cover it.
You have to design to be renumberable.

_______________________________________________

Ietf@xxxxxxxx
https://www1.ietf.org/mailman/listinfo/ietf

[Index of Archives]     [IETF Annoucements]     [IETF]     [IP Storage]     [Yosemite News]     [Linux SCTP]     [Linux Newbies]     [Fedora Users]