DHCP clarification
Kanoj Sarcar <[email protected]>
| Newsgroups | gmane.ietf.ipoib |
|---|---|
| Message-ID | <[email protected]> |
Hi,
While going over section 2 of ipoib/dhcp draft, I realized that it
can be cleaned up somewhat (in my opinion, ie; to others, it might
be quite clear already). Accordingly, I came up with the following
verbiage. If there are some improvements in here, it should be used
to reword the section.
2.2 Use of the BROADCAST flag
A DHCP client on IPoIB MUST set the BROADCAST flag (and
set 'ciaddr' to zero) in DHCPREQUEST messages and
DHCPDISCOVER messages sent when it is not in the BOUND
or RENEWING states (ie it is in INIT-REBOOT or SELECTING
states).
For other cases, the client SHOULD NOT set the BROADCAST
flag if it can receive the server's unicast responses.
As described in [RFC2131], 'ciaddr' MUST be filled in
with client's IP address during BOUND, RENEWING or
REBINDING states. In these cases,
the DHCP server attempts to unicast DHCP responses to
the address filled in by the client in 'ciaddr' by using
IPoIB ARP to resolve the link address.
The reason I think this is clearer is because:
1. It makes it clear that the BROADCAST flag has to be set in
DHCPDISCOVER.
2. It makes it clear that the BROADCAST flag needs to be set
for DHCPREQUEST only in INIT-REBOOT/SELECTING states.
3. It allows that servers might broadcast responses
(allowed per 2131, see last paragraph section 4.1).
4. It allows that servers might respond with DHCPNAK.
5. It allows that there might be other reasons for clients to
set BROADCAST bit (specifically for INFORM, see 2131 table 5).
6. It does not make it illegal for clients to set BROADCAST bit
for whatever other reason. Unless there is a good reason (other
than known issues) to make it illegal, I am not sure if this
was intended. I could not find any MUST NOT reference wrt BROADCAST
bit in 2131.
Thanks.
Kanoj