[dhcp] Limit maximum number of DHCP discovery deferrals
For switches which remain permanently in the non-forwarding state (or
which erroneously report a non-forwarding state), ensure that iPXE
will eventually give up waiting for the link to become unblocked.
Originally-fixed-by: Wissam Shoukair <wissams@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[dhcp] Extract timing parameters out to config/dhcp.h
iPXE uses DHCP timeouts loosely based on values recommended by the
specification, but often abbreviated to reduce timeouts for reliable
and/or simple network topologies. Extract the DHCP timing parameters
to config/dhcp.h and document them. The resulting default iPXE
behavior is exactly the same, but downstreams are now afforded the
opportunity to implement spec-compliant behavior via config file
overrides.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown