[243] in Resnet-Forum
Re: Bootp
daemon@ATHENA.MIT.EDU (paul@atlas.abccomp.oz.au)
Sun Apr 17 20:27:34 1994
From: paul@atlas.abccomp.oz.au
Date: Mon, 18 Apr 1994 10:12:36 -0500
To: Bill Chen <chen@columbia.edu>, resnet-forum@MIT.EDU
Thus expounded Bill Chen on Apr 15, 6:37pm:
/--------------------
|
|Hi,
|
|There's been some recent postings about locally hacked bootp servers
|that distribute IP addresses on the fly. We had considered something
|like that here at Columbia, but I was wondering what you all did to
|recover the addresses once you've distributed them. Is it some sort of
|time out algorithm, or is there something active that happens or both?
|Do you take into consideration issues such as the computer crashing,
|or turned off, etc.?
We sell a commercial RARP server which allocates addresses on the fly -
BOOTP will be done as soon as I can convince the boss it'll fly!
We recover addresses bvy actively ARPing each allocated address, at some
user-controlled rate (usually around one ARP per second, so each machine
gets tested every couple of minutes or so). If a machine does not answer
5 consecutive ARPs, the address is considered available for re-allocation.
We also ARP addresses that shouldn't be allocated, to see if someone is using
addresses in the RARP servers range without permission, and flag possible
duplicate hardware/IP combinations in various flavours. Some sites have used
it just to check they don;t have any duplicated manually-assigned addresses,
wiothout using the allocation feature at all!
I expect BOOTP could work the same - only an ARP would be required, not a full
ICMP PING, which would double the traffic for most cache sizes (as the initial
ARP would probably be required anyhow, and if it responds to the ARP...!)
--
Paul Brooks |paul@abccomp.oz.au |Emerging Standard:
TurboSoft Pty Ltd |pwb@newt.phys.unsw.edu.au| one that has not yet
579 Harris St., Ultimo | | been superseded.
Sydney Australia 2007 |ph: +61 2 281 3155 |
