>> [root@localhost ~]# tcpdump port 69 -v -i em1
>> tcpdump: listening on em1, link-type EN10MB (Ethernet), capture size
>> 65535 bytes
>> 19:41:53.028845 IP (tos 0x0, ttl 20, id 2, offset 0, flags [none],
>> proto UDP (17), length 55)
>>     dhcp-101.larsenhaus.org.ah-esp-encap >
>> kickstart.larsenhaus.org.tftp:  27 RRQ "pxelinux.0" octet tsize 0
>> 19:41:55.027661 IP (tos 0x0, ttl 20, id 3, offset 0, flags [none],
>> proto UDP (17), length 55)
>>     dhcp-101.larsenhaus.org.acp-port > kickstart.larsenhaus.org.tftp:
>>  27 RRQ "pxelinux.0" octet tsize 0
>> 19:41:59.037376 IP (tos 0x0, ttl 20, id 4, offset 0, flags [none],
>> proto UDP (17), length 55)
>>     dhcp-101.larsenhaus.org.msync > kickstart.larsenhaus.org.tftp:  27
>> RRQ "pxelinux.0" octet tsize 0
>> 19:42:05.024477 IP (tos 0x0, ttl 20, id 5, offset 0, flags [none],
>> proto UDP (17), length 55)
>>     dhcp-101.larsenhaus.org.gxs-data-port >
>> kickstart.larsenhaus.org.tftp:  27 RRQ "pxelinux.0" octet tsize 0
>> 19:42:12.988945 IP (tos 0x0, ttl 20, id 6, offset 0, flags [none],
>> proto UDP (17), length 55)
>>     dhcp-101.larsenhaus.org.vrtl-vmf-sa >
>> kickstart.larsenhaus.org.tftp:  27 RRQ "pxelinux.0" octet tsize 0
>> 19:42:22.932113 IP (tos 0x0, ttl 20, id 7, offset 0, flags [none],
>> proto UDP (17), length 60)
>>     dhcp-101.larsenhaus.org.newlixengine >
>> kickstart.larsenhaus.org.tftp:  32 RRQ "pxelinux.0" octet blksize 1456
>>
>>
>> But no boot.
>>
>>
>> During my research I saw a post somewhere that talked about tftp
>> having issues with some RealTek network cards. The kickstart server is
>> running a controller with the RTL8101E/RTL8102E chipset. The poster
>> said he fixed his problem by setting the tftp block size explicitly to
>> 512, but I've been unable to determine how to do so.
>>
>>
>> Are there any obvious errors in my configuration? If not, can anyone
>> advise how to set the tftp block size? Thanks in advance.
>>
>>
>> James
>>
>>
>
>Did you check your SELinux and iptables?
>
>And for Blocksize, I think in the tftp manual we do have --blocksize.
>I think you need to figure out how do do that in the configuration.
>
>--
>Xinyun Zhou

Thanks for your response, Xinyun. Yes, I disabled SELinux and the firewall for testing during setup:

[root@kickstart ~]# cat /etc/sysconfig/selinux 

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of these two values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected. 
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

[root@kickstart ~]# systemctl status iptables.service
iptables.service - IPv4 firewall with iptables
   Loaded: loaded (/usr/lib/systemd/system/iptables.service; disabled)
   Active: inactive (dead)

Aug 27 19:21:50 kickstart.larsenhaus.org systemd[1]: Stopped IPv4 firewall with iptables.

[root@kickstart ~]# systemctl status ip6tables.service
ip6tables.service - IPv6 firewall with ip6tables
   Loaded: loaded (/usr/lib/systemd/system/ip6tables.service; disabled)
   Active: inactive (dead)

Aug 27 20:09:48 kickstart.larsenhaus.org systemd[1]: Stopped IPv6 firewall with ip6tables.

I figured out how to set the block size to 512 but it didn't help. Any other ideas would be appreciated.  :-)