[dhcwg] RE: Maximum message size interpretation in DHCP packet
"Gopi Krishna" <Gopi.Krishna@worldwidepackets.com> Tue, 19 February 2002 20:13 UTC
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From: Gopi Krishna <Gopi.Krishna@worldwidepackets.com>
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Subject: [dhcwg] RE: Maximum message size interpretation in DHCP packet
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Hi, Does not it include the ethernet header besides IP,UDP and DHCP in finding the Maximum DHCP Packet size? Thanks in advance. -Gopi -----Original Message----- From: dhcwg-admin@ietf.org [mailto:dhcwg-admin@ietf.org] Sent: Tuesday, February 19, 2002 9:01 AM To: dhcwg@ietf.org Subject: dhcwg digest, Vol 1 #174 - 3 msgs Send dhcwg mailing list submissions to dhcwg@ietf.org To subscribe or unsubscribe via the web, visit https://www1.ietf.org/mailman/listinfo/dhcwg or, via email, send a message with subject or body 'help' to dhcwg-request@ietf.org You can reach the person managing the list at dhcwg-admin@ietf.org When replying, please edit your Subject line so it is more specific than "Re: Contents of dhcwg digest..." Today's Topics: 1. Re: Maximum message size interpretation (Tobin Coziahr) 2. Re: Maximum message size interpretation (Thomas Narten) 3. Re: Maximum message size interpretation (Tobin Coziahr) --__--__-- Message: 1 Date: Tue, 19 Feb 2002 01:22:08 -0800 From: Tobin Coziahr <tobin.coziahr@sun.com> Organization: Sun Microsystems To: Bud Millwood <budm@weird-solutions.com> CC: DHCP discussion list <dhcwg@ietf.org> Subject: Re: [dhcwg] Maximum message size interpretation Bud- The Maximum Message Size option is also known as the "maximum DHCP message size" option (See RFC 2131, page 9-10). This ONLY refers to the size of the DHCP packet itself, without the IP and UDP headers. The point of the option is to let servers use messages larger than 548 bytes, which is the default max. So no, don't subtract the header size. -Tobin Bud Millwood wrote: > > When a client gives my server the maximum message size it can receive, should > I interpret that as the total IP packet size the client can receive or just > the size of the DHCP portion? > > >From the description of this option, it appears that I should interpret the > value as the size of the entire IP packet the client can receive. > > In other words, should I subtract IP and UDP header sizes from a client's > Maximum Message Size value? > > - Bud > > Bud Millwood > Weird Solutions, Inc. > http://www.weird-solutions.com > tel: +46 70 566 7803 > fax: +46 8 758 3687 > mailto:budm@weird-solutions.com > > _______________________________________________ > dhcwg mailing list > dhcwg@ietf.org > https://www1.ietf.org/mailman/listinfo/dhcwg -- Tobin Coziahr 650-786-7118 (x87118) Solaris Networking tobin.coziahr@sun.com Sun Microsystems --__--__-- Message: 2 To: Tobin Coziahr <tobin.coziahr@sun.com> cc: Bud Millwood <budm@weird-solutions.com>, DHCP discussion list <dhcwg@ietf.org> Subject: Re: [dhcwg] Maximum message size interpretation Date: Tue, 19 Feb 2002 06:34:04 -0500 From: Thomas Narten <narten@us.ibm.com> > The Maximum Message Size option is also known as the "maximum DHCP > message size" option (See RFC 2131, page 9-10). This ONLY refers to the > size of the DHCP packet itself, without the IP and UDP headers. The > point of the option is to let servers use messages larger than 548 > bytes, which is the default max. > So no, don't subtract the header size. Hmm. That's not what draft-ietf-dhc-csr-06.txt says: > stack is capable of reassembling fragmented IP datagrams. In this > case, the client SHOULD set the value of this option to at least > the MTU of the interface that the client is configuring. The > client MAY set the value of this option higher, up to the size of > the largest UDP packet it is prepared to accept. (Note that the > value specified in the Maximum DHCP Message Size option is the > total maximum packet size, including IP and UDP headers.) Is the above text correct? Thomas --__--__-- Message: 3 Date: Tue, 19 Feb 2002 03:59:42 -0800 From: Tobin Coziahr <tobin.coziahr@sun.com> Organization: Sun Microsystems To: Thomas Narten <narten@us.ibm.com> CC: Bud Millwood <budm@weird-solutions.com>, DHCP discussion list <dhcwg@ietf.org> Subject: Re: [dhcwg] Maximum message size interpretation My apologies, you're right. All of the information I just found on the subject notes that the minimum value for this option is 576, which along with the RFC that you quoted shows that I was mistaken. The Maximum Message Size option DOES include the IP and UDP headers. Thanks for the correction, Thomas. -Tobin Thomas Narten wrote: > > > The Maximum Message Size option is also known as the "maximum DHCP > > message size" option (See RFC 2131, page 9-10). This ONLY refers to the > > size of the DHCP packet itself, without the IP and UDP headers. The > > point of the option is to let servers use messages larger than 548 > > bytes, which is the default max. > > > So no, don't subtract the header size. > > Hmm. That's not what draft-ietf-dhc-csr-06.txt says: > > > stack is capable of reassembling fragmented IP datagrams. In this > > case, the client SHOULD set the value of this option to at least > > the MTU of the interface that the client is configuring. The > > client MAY set the value of this option higher, up to the size of > > the largest UDP packet it is prepared to accept. (Note that the > > value specified in the Maximum DHCP Message Size option is the > > total maximum packet size, including IP and UDP headers.) > > Is the above text correct? > > Thomas > > _______________________________________________ > dhcwg mailing list > dhcwg@ietf.org > https://www1.ietf.org/mailman/listinfo/dhcwg -- Tobin Coziahr 650-786-7118 (x87118) Solaris Networking tobin.coziahr@sun.com Sun Microsystems --__--__-- _______________________________________________ dhcwg mailing list dhcwg@ietf.org https://www1.ietf.org/mailman/listinfo/dhcwg End of dhcwg Digest _______________________________________________ dhcwg mailing list dhcwg@ietf.org https://www1.ietf.org/mailman/listinfo/dhcwg
- [dhcwg] RE: Maximum message size interpretation iā¦ Gopi Krishna
- Re: [dhcwg] RE: Maximum message size interpretatiā¦ Tobin Coziahr