I'm not sure, but the second "-m length --length 20" is redundant. You only get to that table if this condition is true. What I'm not clear about the length module is if it is the rule that gets limited or something else. If it's the rule, then this would drop any packet over 20 bytes after there have been 5 per second.
Do you want to limit it by IP address? Then I recommend you use the "recent" feature:
Hi Friends,
I am having a funny problem with grep. When I run
grep 'expr' file.txt
things work fine. But when try to get the line number using the -n option, i.e,
grep -n 'expr' file.txt
I get a message, "grep: 0652-226 Maximum line length of 2048 exceeded."
If the line has more than... (3 Replies)
Hi All,
I am running a IPv6 UDP server, which is bound to in6addr_any. When I send a packet from a client to the link-local address of any interface on the linux box, the server accepts the packets. But when I send the packets to the global address the server doesnt pick the packets.
On... (0 Replies)
Hi!
Can you please help me with one question?
Does rexec command have some limitation of the length of the deliveded cmd?
Thanks in advance,
Anta (2 Replies)
I am trying to use the following code:
awk '{s=$0;if(length(s) < 750){getline; s=s " " $0}printf("%s\n",s)}' filename
but an error shows that 'awk' is too long. Is there a limit to the awk length function? and what could be an alternate solution for long fixed width records?
The code... (3 Replies)
Hi all,
I am new to Linux kernel.
we have a c file that counts the no. of sends and received packets in each interface, and indicate the user about the error/drop ration of incoming and outgoing packets.
in our Linux box , the incoming packets are dropped at random interval.
we have our... (1 Reply)
hello,
can anyone suggest how to delay the incoming packets ??
or how the packets are prossed inside the kernal and a way to make the packets wait a while??
it wud be vry helpful
regards
sameer (7 Replies)
I am looking for an iptables command to allow incoming UDP packets for my Linux server
also is there a command I can use to set the default action for outgoing packets to accept?
Thank you (1 Reply)
Hello, I'm trying to route all packets arriving at a particular interface by entering the same interface
the virtual interface eth1: 2 and now everything is routed by default gw configured on eth1.
eth1 Link encap:Ethernet HWaddr 0a:0e:64:18:52:72
inet addr:192.168.10.15
eth1:2 ... (1 Reply)
Hi folks,
I have a debian server running an Apache daemon on the eth0 interface. Now from time to time the server has to open an openvpn connection (tun0) to other networks to get some data from there. During this period the Apache is no longer reachable under it's IP address on eth0 because all... (6 Replies)
Discussion started by: flyingwalrus
6 Replies
LEARN ABOUT DEBIAN
udp
UDP(4) BSD Kernel Interfaces Manual UDP(4)NAME
udp -- Internet User Datagram Protocol
SYNOPSIS
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
int
socket(AF_INET, SOCK_DGRAM, 0);
DESCRIPTION
UDP is a simple, unreliable datagram protocol which is used to support the SOCK_DGRAM abstraction for the Internet protocol family. UDP
sockets are connectionless, and are normally used with the sendto(2) and recvfrom(2) calls, though the connect(2) call may also be used to
fix the destination for future packets (in which case the recv(2) or read(2) and send(2) or write(2) system calls may be used).
UDP address formats are identical to those used by TCP. In particular UDP provides a port identifier in addition to the normal Internet
address format. Note that the UDP port space is separate from the TCP port space (i.e., a UDP port may not be ``connected'' to a TCP port).
In addition broadcast packets may be sent (assuming the underlying network supports this) by using a reserved ``broadcast address''; this
address is network interface dependent.
Options at the IP transport level may be used with UDP; see ip(4).
ERRORS
A socket operation may fail with one of the following errors returned:
[EISCONN] when trying to establish a connection on a socket which already has one, or when trying to send a datagram with the desti-
nation address specified and the socket is already connected;
[ENOTCONN] when trying to send a datagram, but no destination address is specified, and the socket has not been connected;
[ENOBUFS] when the system runs out of memory for an internal data structure;
[EADDRINUSE] when an attempt is made to create a socket with a port which has already been allocated;
[EADDRNOTAVAIL] when an attempt is made to create a socket with a network address for which no network interface exists.
MIB VARIABLES
The udp protocol implements a number of variables in the net.inet branch of the sysctl(3) MIB.
UDPCTL_CHECKSUM (udp.checksum) Enable udp checksums (enabled by default).
UDPCTL_MAXDGRAM (udp.maxdgram) Maximum outgoing UDP datagram size
UDPCTL_RECVSPACE (udp.recvspace) Maximum space for incoming UDP datagrams
udp.log_in_vain For all udp datagrams, to ports on which there is no socket listening, log the connection attempt (disabled by default).
udp.blackhole When a datagram is received on a port where there is no socket listening, do not return an ICMP port unreachable message.
(Disabled by default. See blackhole(4).)
SEE ALSO getsockopt(2), recv(2), send(2), socket(2), blackhole(4), inet(4), intro(4), ip(4)HISTORY
The udp protocol appeared in 4.2BSD.
BSD June 5, 1993 BSD