CentOS - Apr 2019 - UEFI and PXE

Chris Adams writes:
> Once upon a time, isdtor <isdtor at gmail.com> said:
> > We have a working PXE setup. I've tried to adapt it to UEFI as per
> > RHEL6 manual, but the client won't boot.
> 
> I have BIOS+UEFI PXE boot set up, although it took some doing.  I still
> use SYSLINUX for BIOS, but GRUB2 plus Red Hat's secure boot shim for
> UEFI.  I never could get SYSLINUX's UEFI support working very well or
> reliably, and it didn't support secure boot at all last I looked.
> 
> I also feed most of the content out via HTTP (much faster than TFTP).
> That includes generating menus on the fly from perl CGIs (I'm
> old-fashioned that way :) ).
> 
> I'm using dnsmasq as my DHCP server, so I have this in its config
(where
> pxesrv.cmadams.net has IP 10.10.10.2):
Thanks for the detailed info. But my setup is different. ISC dhcpd is set up as
per
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/installation_guide/s1-netboot-pxe-config-efi,
and grub.

next-server points to to the tftp server but seems to be ignored. When the
client boots, tcpdump reports

09:02:02.911381 IP client.cisco-ipsla > dhcp-server.tftp:  56 RRQ
"linux-install/bootx64.efi" octet tsize 0 blksize 32768
09:02:02.911403 IP dhcp-server > client: ICMP dhcp-server udp port tftp
unreachable, length 92

on the dhcp server and nothing on the tftp server. The dhcp server also logs
that a DHCPOFFER is made and accepted by the client.

This poster had the same problem and it was not resolved.
https://superuser.com/questions/1182862/uefi-mode-pxe-booting-doesnt-work

On Thu, Apr 25, 2019 at 5:25 AM isdtor <isdtor at gmail.com> wrote:
> 09:02:02.911381 IP client.cisco-ipsla > dhcp-server.tftp:  56 RRQ
> "linux-install/bootx64.efi" octet tsize 0 blksize 32768
> 09:02:02.911403 IP dhcp-server > client: ICMP dhcp-server udp port tftp
> unreachable, length 92
>
The ?ICMP unreachable? should be a dead giveaway. . .

You are missing the `firewall-cmd` configuration. See this guide:

https://www.bo-yang.net/2015/08/31/centos7-install-tftp-server

Once upon a time, Steven Tardy <sjt5atra at gmail.com>
said:
> The ?ICMP unreachable? should be a dead giveaway. . .
You cut out the part of the email where the OP said that the UEFI system
was ignoring the next-server part of the DHCP reply and trying to TFTP
to the DHCP server instead of the TFTP server.  Of course that got ICMP
unreachable, but it isn't a firewall problem.

To the OP: can you post a full tcpdump decode of the DHCP offer?  I
seem to remember having some issue with ISC DHCP in the past not getting
the next server set correctly - maybe a packet will jog some memory (and
I'll go try to grab the same from my dnsmasq DHCP for comparison).

-- 
Chris Adams <linux at cmadams.net>