Failed to send 300 byte long packet over fallback interface

  • by

1.0 Error

While configuring a server, the following errors were noted in the logfiles.

send_packet: Operation not permitted
dhclient.c:2386: Failed to send 300 byte long packet over fallback interface.
DHCPREQUEST on eth0  port 67 (xid=0x1580bfd0)
...

2.0 Solution

There are two possibilities depending upon whether DHCP is being used for getting the network IP address or not.

2.1 DHCP is not being used

There may be an error in the network configuration. For example, the file /etc/network/interfaces may be having entries like the following:

...
# The primary network interface
auto eth0
iface eth0 inet dhcp
...

This needs to be changed to something similar to what is given below:

...
auto eth0
iface eth0 inet static
# The primary network interface
    address 192.0.2.100/24
    gateway 192.0.2.1
    dns-nameservers 192.0.2.5 192.0.2.6
    dns-search example.com
    dns-options rotate
...

2.2 DHCP is being used

The problem could be because of firewall not permitting UDP packets on port 67 for DHCP. The problem can be resolved by allowing outgoing UDP packets on port 67. The following iptables rule may be added,

iptables -A OUTPUT -p udp  -o eth0 --dport 67 --sport 1024:65535 -j ACCEPT
Subscribe
0 0 votes
Article Rating
Subscribe
Notify of
guest
0 Comments
Inline Feedbacks
View all comments

You may like these, also

  • POSIX message queues in LinuxPOSIX message queues in Linux 1.0 POSIX Message queues POSIX interprocess comunication (IPC) was introduced in the POSIX.1b standard (IEEE Std 1003.1b-1993) for real time…
  • POSIX Shared Memory in LinuxPOSIX Shared Memory in Linux 1.0 Shared Memory Shared memory is the fastest method of interprocess communication (IPC) under Linux and other Unix-like systems. The…
  • POSIX Semaphores in LinuxPOSIX Semaphores in Linux 1.0 Semaphores Semaphores are used for process and thread synchronization. Semaphores are clubbed with message queues and shared memory under…
  • fork and exec system calls in Linuxfork and exec system calls in Linux 1.0 fork and exec system calls Suppose we wish to write a "shell program" which would execute another program. Now,…
  • Connecting two computers with Ethernet LAN cableConnecting two computers with Ethernet LAN cable Quite often, we wish to connect two computers back to back using an Ethernet LAN cable. It may be because…
  • D-Bus TutorialD-Bus Tutorial 1.0 D-Bus D-Bus is a mechanism for interprocess communication under Linux and other Unix-like systems. D-Bus has a layered architecture.…
  • Socket programming using the select system callSocket programming using the select system call 1.0 Client-Server Paradigm The Client-Server paradigm divides the software architecture of a system in two parts, the server and its…
  • System V message queues in LinuxSystem V message queues in Linux 1.0 Message queues Message queues are one of the interprocess communication mechanisms available under Linux. Message queues, shared memory and…
  • POSIX Threads Synchronization in CPOSIX Threads Synchronization in C 1.0 POSIX Threads Synchronization POSIX Threads provide multiple flows of execution within a process. The threads have their own stacks…
  • System V Shared Memory in LinuxSystem V Shared Memory in Linux 1.0 Shared Memory Shared memory is one of the three interprocess communication (IPC) mechanisms available under Linux and other Unix-like…