Maximum count of ms-classless-static-routes

[David W. Hankins]

On Thu, Jul 09, 2009 at 11:49:17AM +0800, Yuriy Ohonin wrote:
> As for as i know, maximum packet size is 4KB. This is much more than 31
> routes even in big unoptimazed string format. Maybe, i'm wrong, what is
> the maximum packet size in this case?

Look for an 'MMS' (maximum message size) option sent by the client.

This is an unfortunate corner of the DHCP protocol, and anything I say
will be wrong because of conflicting and incompatible interpretations
of RFC 2131, but I think the most correct thing to say is that the
safest/most-compatible behaviour is to use a 576 octet packet size
from ethernet frame start to tail of the DHCP options field (but not
counting ethernet's trailing CRC), UNLESS the mss option is supplied,
in which case this measures the same packet field distance.

However, many clients do not send an MMS option, because many relay
agents drop packets over 576 octets.

-- 
David W. Hankins	"If you don't do it right the first time,
Software Engineer		     you'll just have to do it again."
Internet Systems Consortium, Inc.		-- Jack T. Hankins
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 194 bytes
Desc: not available
URL: <https://lists.isc.org/pipermail/dhcp-users/attachments/20090713/e44d70e2/attachment.bin>