Troubleshoot TFTP

Testing TFTP

Try to get a file with Linux:

tftp -v x.x.x.x -c get undionly.kpxe
Connected to x.x.x.x (x.x.x.x), port 69
getting from 10.2.1.11:undionly.kpxe to undionly.kpxe [netascii]
Received 89509 bytes in 0.0 seconds [84047115 bit/s]

Try to get a file with Windows:

tftp x.x.x.x get undionly.kpxe

TFTP Service

Fedora 20/21

status/enable/restart

systemctl status xinetd.service
systemctl enable xinetd.service
systemctl restart xinetd.service

Ubuntu

newer systems:

status/enable/restart

service tftpd-hpa status
service tftpd-hpa restart
service tftpd-hpa enable

older systems:

status/enable/restart

sudo /etc/init.d/xinetd status
sudo /etc/init.d/xinetd restart
sudo /etc/init.d/xinetd enable

TFTP Settings file

Fedora:

Location:

/etc/xinetd.d/tftp

To display /etc/xinetd.d/tftp:

cat /etc/xinetd.d/tftp

It should look a whole lot like this:

# default: off
# description: The tftp server serves files using the trivial file transfer #   protocol.  
#The tftp protocol is often used to boot diskless workstations, download configuration files to network-aware printers, 
# and to start the installation process for some operating systems.
service tftp
{
        socket_type             = dgram
        protocol                = udp
        wait                    = yes
        user                    = root
        server                  = /usr/sbin/in.tftpd
        server_args             = -s /tftpboot
        disable                 = no
        per_source              = 11
        cps                     = 100 2
        flags                   = IPv4
}

To edit /etc/xinetd.d/tftp:

sudo vi /etc/xinetd.d/tftp

Explanation of settings for /etc/xinetd.d/tftp:

man xinetd.conf

Ubuntu:

Location:

/etc/default/tftpd-hpa

To display /etc/default/tftpd-hpa:

cat /etc/default/tftpd-hpa

It should look a whole lot like this:

# /etc/default/tftpd-hpa
# FOG Modified version
TFTP_USERNAME="root"
TFTP_DIRECTORY="/tfptboot"
TFTP_ADDRESS="0.0.0.0:69"
TFTP_OPTIONS="-s"

To edit /etc/default/tftpd-hpa:

sudo vi /etc/default/tftpd-hpa

Explanation of settings for /etc/default/tftpd-hpa:

man tftpd-hpa

Instructions on using Vi:

Vi

Troubleshooting TFTP

Testing using Windows

To test from windows, TFTP Client must be installed and the Firewall must allow TFTP Traffic. The best way to guarantee that your windows firewall isn't blocking TFTP is to turn it off during your troubleshooting.

Using Windows 7 Pro:

Control Panel -> Programs and Features -> Turn Windows Features on or off -> TFTP Client

Disable/verify Firewall

Fedora 20/21

systemctl disable firewalld.service

systemctl stop firewalld.service

Can be undone with "start" and "enable".

Check status of firewall:

systemctl status firewalld.service

Fedora 16

Add /bin/bash to /etc/shells as the vsftpd yum install does not do it correctly causing tftp timeout message

Check Firewall in Debian/Ubuntu

sudo iptables -L

If disabled, the output should look like this:

Chain INPUT (policy ACCEPT)
target prot opt source destination 

Chain FORWARD (policy ACCEPT)
target prot opt source destination 

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

Disable Ubuntu Firewall

sudo ufw disable

Disable Debian Firewall

iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT

Disable Windows firewall

It's necessary to disable the Windows firewall when using windows for testing. The below image demonstrates disabling the firewall which allows TFTP traffic to pass.

Permissions

Check permissions on /tftpboot directory by using:

ls -laR /tftpboot

Set permissions to allow everyone full access to /tftpboot and all contents:

chmod -R 777 /tftpboot

See example permissions below:

Check Network Switch settings

See IPXE for network switch settings concerning STP/portfast/etc.

DHCP Settings

• It is important to know that versions 0.32 and below use pxelinux.0 for option 67 in DHCP
• For all versions 0.33 to current(1.3.0beta) use undionly.kpxe is generally recommended for option 67.
  • Other files that can be used are listed in your directory "/tftpboot"

Linux Based (ISC-DHCP)

Articles related to ISC-DHCP

BIOS and UEFI Co-Existence

ProxyDHCP with dnsmasq

FOG on a MAC

Fedora 21 Server#Verify Fedora DHCP config (if_using_DHCP)

Start/stop/enable/disable

Configure DHCP

FOG dnsmasq (ProxyDHCP)

• You would use ProxyDHCP if you do not have access to your DHCP server, or are using a device that isn't capable of specifying option 066 and 067 (next server and file name). The most popular ProxyDHCP method with fog is dnsmasq. This article will walk you through that:

• Not required unless you have an unmodifiable DHCP server/

Using_FOG_with_an_unmodifiable_DHCP_server/_Using_FOG_with_no_DHCP_server

Non-Linux DHCP

If you do not use FOG to provide DHCP services, the following sections will give some indication of settings for DHCP servers on various platforms.

Windows Server DHCP

• Option 66
  • 
• Option 67
  • 

Novell (Linux) Server DHCP

• DHCP Overview from DNS/DHCP Console (Netware 6.5)
  • 
• Option 66
  • 
• Option 67
  • 

Here is a link from Novell's website on how to setup their DHCP server: http://www.novell.com/coolsolutions/feature/17719.html

MAC Server DHCP

Use OS X Server app to install and utilize DHCP.

Use DHCP Option Code Utility to generate the code necessary.
https://docs.google.com/uc?id=0BwD4il5Z1G6fTmFFYU91bDNuRmc&export=download

One MUST generate the codes in order for PXE booting to work!
bootpd.plist is located in /etc/bootpd.plist

• Option 66
  • 
    
• Option 67
  • 
    

• Sample bootpd.plist
  
  • This is a sample file DO NOT USE THIS IN YOUR ENVIRONMENT!!!! OS X Server app will generate most of this code for you, this example file is to show you the place where the generated code needs to be placed.
    
  • For Reference, your generated code should be placed between "dhcp_domain_search" and "dhcp_router"
    

• Completed Bootpd.plist
  
  • 
    

Other DHCP Configurations

Other DHCP Configurations

Common problems and fixes

Unable to connect to tftp server

For Versions Before 0.24

This seems to be caused by a password issue,

1. From the fog management interface, go to users.
2. Reset the fog user password.
3. Click the "I" icon - "Other Information"
4. Click "Fog Settings" in the menu on the left
5. Replace the FOG_TFTP_FTP_PASSWORD and the FOG_NFS_FTP_PASSWORD fields under FOG settings with 
   your Linux fog user password. (Seems like FOG_NFS_FTP_PASSWORD is gone for ver .24).

For Versions .24-.32

• Reset the local password for user fog with: [sudo] passwd fog
• In management front end, go to Storage Management -> All Storage Nodes
• Click on DefaultMember
• Change the Management Password to match the password you just changed.
• Then go to Other Information and change FOG_TFTP_FTP_PASSWORD also.

• Go to your fog web location, on Red Hat and CentOS is in:

/var/www/html/fog/

Then open the file:

/commons/config.php

and check the values of: TFTP_FTP_PASSWORD and STORAGE_FTP_PASSWORD

These MUST match the password you set above, if not write them properly in here

Finally reload of the service

/etc/init.d/vsftpd reload

---

Verify Server Settings

If you have modified your server setup since first install, then the new changes must be updated and verified in the Fog Settings menu. It might not be enough to just re-run the installer. For instance, a new IP lease will cause the server to show the Unable to connect to tftp server error message.

• Go to the "I" icon, which is the About menu in 0.29
• Select Fog Settings and navigate down to TFTP Settings and verify that all options are correct for your setup.

Ensure nothing else on the network is conflicting with the DHCP server

I had this error the past two days and tried all of the standard suggestions. Finally Wireshark came to the rescue. I discovered a second, feral DHCP server on the network that wasn't issuing IP addresses but must have been running interference somehow. When I disconnected it from the network, PXE boot worked as expected.