Subject: Bootp "sname" field

From: [email-masked]
Date: Thu, 29 Jun 2000 08:39:25 -0500

It seems to me RFC951 indicates that a client can specify a server name by
using "sname" field.  My question is that if a client directly requests a
server that's not on the same subnet with the client, it will have to go
through a router, will then the router still be considered as a relay
agent?

For example, I have two ranges of class c addresses.  One is used for
static (let's say it's 200.10.11, with 200.10.11.x as router interface),
the other (let's see it's 200.10.10)is used for DHCP/Bootp.  I have
200.10.10.x configured as relay agent for all 200.10.10.0.  In above
scenario, would the packets from the client goes through 200.10.10.x
interface or go through 200.10.11.x interface?

Thanks!

HDay

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From: Bernie Volz <[email-masked]>
Date: Thu, 29 Jun 2000 10:21:58 -0400

See section 7.3, that might help explain some of the behavoir?

I'm not exactly clear on your configuration. Where are you using BOOTP? If
you're using BOOTP on the .10. network, then the relay agent would forward
the packets to one or more BOOTP Servers. Section 7.3 then explains how a
bootp server might handle this.

- Bernie Volz

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Thursday, June 29, 2000 9:39 AM
To: DHCPv4 discussion list
Subject: Bootp "sname" field

Thanks!

HDay

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From: Bernie Volz <[email-masked]>
Date: Thu, 29 Jun 2000 10:55:08 -0400

This still sounds like a confusing configuration. Not sure I fully
understand it.

By "static", I assume you mean the addresses are preconfigured on the
clients.

And, I assume your clients are on BOTH subnets?

I'm not sure what you mean by "control the clients on the static only subnet
from using bootp".

The bootp client also likely needs to be a bit special since it needs to
send the MAC address of the .10. interface, yet it will send the packet out
the .11. interface (since it knows the server's address, right).

With bootp, you usually have a mac address to ip address list, so just don't
put the .11. interface mac addresses in the table.

Or, are you really trying to use dhcp?

- Bernie

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Thursday, June 29, 2000 10:44 AM
To: Bernie Volz
Cc: DHCPv4 discussion list
Subject: RE: Bootp "sname" field

well, let's see if I can explain a bit better.  If a bootp Client sends out
a unicast packet to a bootp server which is not on the same subnet as the
client, then this packet will have to be forwarded by a router who knows
where the server is at.  Let's say if I have to control which subnet can
use bootp, and I have both .10 (dhcp/bootp) and .11(static) configured for
subnets that are enabled for bootp, but only .11 (for static only)
configured for subnets that aren't supposed to use bootp.  If a client on
the .11 subnet knows the bootp server name, it will be able to use the .11
interface on the router to get to the server and get configured by the
server.  Is this right?  If so, then I won't be able to control the clients
on the static only subnet from using bootp.

Is this correct?  Thanks

Hday

Bernie Volz <[email-masked]> on 06/29/2000 09:21:58 AM

To:   Hannah O Day/Rochester/IBM@IBMUS
cc:   DHCPv4 discussion list <[email-masked]>
Subject:  RE: Bootp "sname" field

- Bernie Volz

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Thursday, June 29, 2000 9:39 AM
To: DHCPv4 discussion list
Subject: Bootp "sname" field

Thanks!

HDay

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From: [email-masked]
Date: Thu, 29 Jun 2000 14:24:37 -0500

Thanks all of you who responded.  I think I got my question answered...

Hday