How can I find out list of multicast addresses and port in use?"netstat -ng" only gives list of multicast addresses that have been joined, it does not give port number.I have several hundred servers running application that listens to several multicast addresses on different ports. I want to write an audit script and get the list of multicast address and port numbers.
View 2 RepliesI am using DHCP on my home network. There could be as many as 5 computers logged in at any given time. Their IP addresses change depending on the sequence they log in.I want to be able to connect to them from any of them (some wired, some wireless) and share files by issuing a mount command for the appropriate shared drive.My question is how to get the IP of each computer when I only know the names of the computers. Pinging the computer name succeeds, but it does not give the IP.In other words I am looking for a Linux command that will come back with a list of IP's with their corresponding computer names so I can issue the right mount command. I would like to issue this command from a Linux terminal, but would also be happy to issue it from a Windows XP station.
View 14 Replies View RelatedIs there some traceroute-like tool that shows ports as well as IP addresses? This is more for seeing how NAT works (on my home network) than for a practical need.
View 5 Replies View RelatedNote the contents of my /etc/apt/sources.list. Only problem is when I run apt-get update there asome 'wheezy' update sources that I must have put it by accident. Where would they be coming from and how do I delete them?
Code: Select all#
# deb cdrom:[Debian GNU/Linux 8.2.0 _Jessie_ - Official amd64 NETINST Binary-1 20150906-11$
#deb cdrom:[Debian GNU/Linux 8.2.0 _Jessie_ - Official amd64 NETINST Binary-1 20150906-11:$
deb http://ftp.au.debian.org/debian/ jessie main
deb-src http://ftp.au.debian.org/debian/ jessie main
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All i need is to see a list, window or anything that shows all of the serial (rs232) com ports that are on my Ubuntu 10.04 machine and what their associated port numbers are.
I have one com port that is on the motherboard (so obviously its com 1) and it works fine. but i also have a usb to serial (FTDI) com port that i cant figure out what the port number is...
I am using 9.10, 64bit. Firefox 3.5.7. When I open a fresh instance of Firefox, I can start typing common addresses in the address field, and it will give me a list to choose from based on what I typed. However If I let the screen saver kick in, I lose that ability, until I close all open firefox windows and reopen them.
View 3 Replies View RelatedHow to list Open ports on Linux?
View 3 Replies View Relatedhow can I check which process is using certain port? Like in a table with processes and used ports...
View 3 Replies View RelatedI have several multicast data feeds that I'm trying to connect to using a minimal server install of Ubuntu as a VM on a VMWare ESXi server.I have another VM on the same server running Solaris that can connect with no issues to the incoming multicast stream.
View 1 Replies View RelatedThis is not a linux specific question more of a general network issue with the hope that someone may have already done this under linux.My problem:I have a red hat linux machine transmitting IP multicast packets onto an ethernet gigabit network (cisco switch).Wireshark (running on a different red hat linux box confirms packets on network.
View 4 Replies View RelatedIf I have set up 2 network interfaces on a box, if I started sending multicast traffic, it will go out through both interfaces? Or is there a way to control through which interface it will go out?
View 1 Replies View RelatedFor the last couple of days, I've been unsuccesfully trying to receive multicast packets on Ubuntu Server 11.04, and seen some strange things along the way. The program i use to test this, is basically http://www.scribd.com/doc/38224328/mcreceive-c.Now the network has been configured to forward me the multicast packets, regardless of the joins. So tcpdump shows me:
Code:
15:16:11.308952 IP 10.164.130.2.61417 > 224.16.17.23.47806: UDP, length 1400
...
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I've got an application that compiles in Windows and Linux and is using UDP multicast to communicate. I'm running it on a Windows machine, a Linux machine and a small board (Gumstix) that is running Linux as well. The Windows and Linux machines have no problems sending/receiving packets with each other. The Gumstix and Linux machines have no problems sending/receiving packets with each other. The Gumstix can also send/receive packets with two instances of the application both running on the Gumstix.
But when running on the Gumstix I can send udp multicast packets to Windows, but cannot receive them. (It works if I do point to point with a known IP port#, but not multicast.) I can run tcpdump on the Gumstix and see the packets, but they are not being received on my socket. Here's what tcpdump (running on the Gumstix) outputs when sending the same packet from different sources. Notice the IP header ID and flags (don't fragment) are different when coming from Windows.
WINDOWS to Gumstix
-7:-45:-2.015784 IP (tos 0x0, ttl 15, id 35331, offset 0, flags [none], proto: UDP (17), length: 444) 172.30.42.3.1165 > 239.255.183.180.47028: UDP, length 416
LINUX to GUMSTIX
-7:-43:-38.451991 IP (tos 0x0, ttl 15, id 0, offset 0, flags [DF], proto: UDP (17), length: 444) 172.30.42.13.32771 > 239.255.183.180.47028: UDP, length 416
GUMSTIX to GUMSTIX
-7:-33:-10.955608 IP (tos 0x0, ttl 15, id 0, offset 0, flags [DF], proto: UDP (17), length: 444) 172.30.42.110.1025 > 239.255.183.180.47028: UDP, length 416
I've tried everything I can think of to get this to work but am not getting anywhere. Also I'm pretty inexperienced when it comes to Linux. Anything I could try to be able to receive udp multicast packets from Windows?
I have 4 interfaces, dvb0_0 - dvb0_3. Each one has a multicast stream coming in on it. The program I am using to decode these streams only accepts one interface though. How can I "combine" so that the program, listening on 1 ip can get all 4 streams? they are on groups 224.0.1.1-4
View 1 Replies View RelatedIn the ipv4 code i was using "ip_mc_join_group()" to join the multicast group. but i cannot find a similar function for ipv6 i have found one ipv6_sock_mc_join() but this function is not available for use with my module as it is not exported.
View 1 Replies View Relatedhave a doubt about the multicast address.I have read that IP and ethernet multicast address have the same last 23 bits. While an ethernet multicast address always starts with 01:00:5E. Changing the last 23 bits of the IP address into hexadecimal form and "adding" them to the first 24 bits we find the ethernet address but what about the missing bit??? For istance I have: 230.11.111.10 = 11100110.00001011.01101111.00001010 So converting the last 23 bits I have b:6f:a The final ethernet address will be 01:00:5E:b:6f:a . And what about the missing bit?
View 1 Replies View RelatedWe have a high speed udp multicast connection. There are about 37 multicast groups and average incoming rate via the connection is about 20000 pkt/sec and peak 40000+ pkt/sec. Each packet is about 100-300 bytes. And there are 6 busiest multicast groups generating 80% of the traffic. No significant outgoing traffic via that interface. The problem is that, if our heavy-weight application create 37 sockets for all the groups, the packet loss become quite frequent. but if we create the 6 sockets for the busiest groups, the packet loss drops to 1/10 of the original level. We can confirm that the lost packets DO arrive in our box because a light-weight recorder on another box on the same ethernet segment can see the lost packets when listening to the same groups. If we start another heavy-weight application for the rest groups (31 groups ) on the same box, the packet loss just come back to the original level.
The packet loss happens not only to the heavy-weight application but also the light-weight recorder running on the same system. that is, the loss is system wide. The socket kernel buffer are all 4MB max and did not observe system buffer overflow. It seems the number of sockets listening to the same multicast group have the most negative impact on packet loss. And the higher traffic have a far less impact on packet loss than the number of sockets. It also seems that there is some limit in the kernel that when socket number are reduced under, the packet loss can significantly ease. How can I further diagnose the problem? Our system is RHEL 5.3 32bit i386, Xeon 2.9GHZ 16 Processors, 32GB memory. Two broadcom giga netowrk card and 6 Intel GIGA NIC, and only one interface card has so much traffic.
I am trying to run some benchmark tests for multicast. What I want to do is have one system send multicast packets and another receive it on all it's interfaces (eth0-eth3). Whenever I run receiver on more than one interface I get echo effect (if I receive on x interfaces then I get same packet x number of times). Is this how it is supposed to behave? It does not make any difference whether I use loop-back or not. I have set SO_REUSEADDR to yes. I run separate instance of receiver on each interface. I am doing this on RHEL5 systems.
# uname -r
2.6.18-164.20.1.el5
I'm trying to receive data that is being broadcast on address 224.0.1.1, 224.0.1.2, 224.0.1.3, 224.0.1.4. ports are 1201, 1202, 1203, 1204 respectively. I can see the data using wireshark but can not get my program to receive the data. all firewalls are shutdown. iptables is not running, i've set net.ipv4_icmp_ignore_broadcasts = 0 and still no luck.
View 1 Replies View RelatedI have just set up an FC 13 box for a small network application. At the core, the application is supposed to receive some data over a multicast on my local network. However, for some reason, I am not being able to receive any multicast data on this machine. Other machines, on the same network (connected on the same layer 2 switch) are receiving the multicast just fine. I have tried the following things:
1. ensure that I am joining the multicast on the correct interface: the machine has only one ethernet card. Also, after starting my application, I use netstat -g to check for group membership. The multicast subscription shows up fine.
2. ensure there is no error in the program: the program works fine on my person linux machine
3. ensure that the multicast is actually available: it is available on all other local machines. I also wrote my own small broadcaster. data from this broadcaster (running on the same box) is available to other machines but not to my own listener program.
4. no firewall/filtering settings on the layer2 switch
5. TTL setting on the broadcast: have tried changing it from 1 through 5 with no effect. Note that even if the broadcast is coming from the same machine, my machine does not pick it up while other machines on the network do so.
I suspect this has to do with some settings on the network card itself. Below is the output of /sbin/ifconfig on the card:
eth0 Link encap:Ethernet HWaddr 00:08:A1:67:BBA
inet addr:192.200.20.32 Bcast:192.200.20.255 Mask:255.255.255.0
inet6 addr: fe80::208:a1ff:fe67:bbca/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
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I have a PC connected by ethernet to a Galil motion controller card.I recently installed Centos 5.The Galil software for communicating with the card is reporting that it can't join a multicast socket group.The software used to work with another version of Linux.
View 6 Replies View RelatedI've just set up an LTSP server, with all its clients on a separate subnet to my main network - the main network is 192.168.1.x, and the LTSP clients are all 192.168.2.x. My LTSP server has 2 NICs, one on each network, and is merrily forwarding normal IP traffic from the clients to the rest of the network. I have a client/server application that has a server on one machine, and clients locate and attach to it using multicast protocols. The server is on the main network, and any other machines on the network can locate and talk to the server quite happily. The LTSP clients, however, cannot - I assume because the multicast communications aren't being forwarded by the LTSP server. How I can get this working?
View 2 Replies View RelatedI got a server setup with three nics
eth0 = wan
eth1 = lan
eth2 = iptv (multicast)
When I have my IPTV inserted in the computer I am either having problems connecting to the internet or recieve the multicast streams from the iptv. I do get a valid ip on both the WAN and IPTV, but I am having problems getting them both to work at the same time.
eth0:
eth0 Link encap:Ethernet HWaddr 00:14:d1:1d:72:39
inet addr:94.xx.xx.63 Bcast:255.255.255.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2180753 errors:0 dropped:0 overruns:0 frame:0
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When trying to run a program, from Gnome terminal, for a device connected to /dev/ttyS0 (COM1), I get a segmentation fault. I think the terminal may not want to leave the connection open for some reason. Do I first need to mount the device somehow?
View 2 Replies View RelatedI am setting up my OMAP4 board. I pluged power cable and USB port.But my OMAP4 blaze does not find ttyUSB*. I tried the same OMAP4 on other Linux machine and it is connecting to /dev/ttyUSB2. Do you know any thing I need to configure on my Linux
View 2 Replies View RelatedWhat UNIX command do you use to find out the open ports in a system?
View 1 Replies View RelatedI just spent an hour at Google and the OpenWRT site looking for something that might be called a "List of Features." I did not find one.
I did find this: url but it is not an official project document so I'm left with as many questions as answers.
I know that OpenWRT uses dynamic packages for feature deployment, but I'd expect some sort of grid page -- package vs. edition -- or similar so that one might have some idea what is available to choose from.
{commentary}
I know that part of the Linux sociology involves some amount of "you just gotta know." However, unless one is a networking maven or wonk one does not know enough about network features to state which features one wants ... much less know what name to use in search or discussion.
I got a bunch of machines (~10) that I share with my co-workers. I have appropriate .ssh file(s) set up so I don't get prompt for password when I try to ssh.Currently I ssh into these hosts and then do a top to check the load before I start using the machine. Because I don't want to be on a busy host.Can someone show me how to write a script that find a least-busy host given a list of hosts to check? (hardcoded is fine)
View 1 Replies View RelatedThe PowerPC does no longer receive commercial support form Canonical. How do I update /etc/apt/sources.list. My goal is to change deb [url]... to [url], using find and replace.
Found something at [url], oh no false alarm! This thread does not explain how to change the /etc/apt/source.list either. I know what to change but do not know how.
I make an application on GNU/Linux which listening on a MULTICAST stream, so I open my unconnected socket, bind it on a MULTICAST address and a port, join the multicast group with the "setsockopt (IP_ADD_MEMBERSHIP)", then I receive datagram on my socket.
Now I've two different instances of the same application that run with their own MULTICAST address and port. And what I found strange is that, after a misconfiguration, I switch the ports, for example:
Emitting on 225.0.0.1/23451 and 225.0.0.2/23452
Receiving on 225.0.0.1/23452 and 225.0.0.2/23451
And my receiving part doesn't care about the MULTICAST address, it looks like the socket is listening on the port number only! I mean that the receiver [225.0.0.1/23452] take its datagrams from emitter [225.0.0.2/23452] and vice-versa!