Networking :: Combining Multiple Interfaces With Multicast?
Apr 1, 2010
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 220.127.116.11-4
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.
I would like a basic firewall on my netbook and first attempted this by using firestarter as i have no experience in writing IPTABLES rules from first principle and to be honest the syntax looks horrific! the problem with firestarted is that when i selected WLAN0 to be the internet connected port everything worked fine until i connected to a VPN at which nothing would work (the only error i got was when pinging an IP address when i got sendmsg not permitted) my normal setup is this.... normally im connected via WLAN0 to the internet. but one one particular network i must activate the VPN to use anything, this creates another interface tun0. both wlan0 and tun0 will be assigned an ip address but only the tun0 will do anything (the wlan0 one is configured by the network to just allow traffic to the vpn gateway and nothing else) what i really need is some way of creating a basic firewall (drop all incomming except ports i specify) that lives on wlan0 unless tun0 is active in which case it moves to tun0
Is there a way to do multiple interfaces in tcpdump? I have found that when using "-i any", not all packets are captured (compared to "-i eth0" on a machine with only one interface). I need to monitor traffic on some machines with as many as 6 interfaces, and get these packets that "-i any" misses. When I give the "-i" option multiple times, it seems to only use the last one.
I have the following setup: Client A, having 2 network interfaces, eth0 and eth1, both with the IP address 192.168.1.1/32. Client B, also having 2 network interfaces, eth0 and eth1, with the IP addresses 192.168.1.2. The routing table on client A has one entry: 192.168.1.2 dev eth0 The routing table on client B has one entry: 192.168.1.2 dev eth1. Basically the idea is to send the upload traffic one one interface and the download traffic on the other interface. (Client B could serve as a gateway). However, with this setup, well... nothing works. The packets received by Client B are ignored. Does the linux kernel have anything against routing packets coming from an interface, although he thinks the source is on another interface?
I have got a problem in the configuration of the network for my Linux box. The distribution is Slackware 12.2 with the 18.104.22.168-smp kernel. There are three ethernet NIC, one on the motherboard with Atheros AR8121/AR8113 chip and two on PCI card which with RealTek 8169. I installed the module for Atheros which is the atl1e.ko and I defined the configuration for the three NICs in /etc/rc.d/rc.inet1.conf. When I hit the commend ifconfig I see all the three interfaces eth0, eth1, and eth2, but the address are not distributed between the NICs as I'd like so I thought to resolve the inconvience with udev, but I don't know how to proceed because there is a strange situation.
If I control the file /etc/udev/rules.d/70-persistent-net.rules I see a strange situation: Once the file contains nonly a line for the Atheros NIC but if I reboot the system there are the two lines for the two RealTek NICs and everytime the system is rebooted there is a change between these two alternatives. A detail I noted is that the two modules atl1e and r8169 are both always loaded, so udev has always the chance to detect the hardware but for some reason that I don't know something goes wrong. Another related problem that bothers me is the absence of udevinfo and udevtest. Have I perhaps to reinstall udev?
Adapter 2: HTC Desire tethered via USB. When I start from scratch, with no remembered networks in the network manager, the Ethernet is shown as "Auto Ethernet". When I then connect the HTC Desire, the new network is shown in the network manager also as "Auto Ethernet". Previously, when I right clicked on the network manager and selected "Edit Connections", there were multiple "Auto Ethernet" entries under the wired tab.
Now (and I do not know what changed, sorry), I only see one entry. When I edit this entry (say, add a route), then the route is added for both network interfaces. This used to still work, so I was not worried about the name clash, but now it is causing problems so I need to have a different name for each network interface.
which takes file 4.dat and adds $2 from 6.dat, but I want a single command to take each $2 from every file and add them to (for example) 4.dat (having $1 from 4.dat is no problem). A command that takes every file in the folder and grabs $2 and places them in a common file would be ideal. Frankly I can work around if you combine both columns from every file.
configure a server with two network interfaces? This system is physically moved from one network to another every few days (different buildings but connected by a VPN). I'd like to be able to control the IP address of the system depending on which port I plug the network cable into with a static setting. Right now the system will connect to the local network, but any requests to go beyond the subnet get lost. The only way I can get the system to talk outside of its subnet is to comment out the second interface.
I have a built-in gigabit Ethernet card which is connected to a router. Router's IP address is 192.168.2.1 My IP is 192.168.2.161 (eth0) I also have a Nokia N900 connected via USB and its IP is 192.168.1.1. It serves as a second router and on that interface (usb0) my IP is 192.168.1.2 N900 is also connected to a wireless network. Router of that network has the IP 10.0.0.1 and N900's IP is 10.0.0.50 (wlan0) My problem is that I want to reach a server at 10.0.0.7 from my computer. Is there a way I can do that?
They are all given different filenames bob_smells.xls, nancy_smells_worse.xls etc. I was wondering using Linux (LUbuntu specifically), would it be possible to combine all of these worksheets into one document, with each of the seperate files becoming a tab / sheet within the one file (And the name reflecting the original name of the document)?
I'm trying to connect one computer to two others in an ad-hoc infrastructure.
[computer 1] ---- [computer 2] ---- [computer 3]
computer 2 is running Linux and has a single NIC wlan0. I want to it to connect to both computer 1 and computer 3 so each computer can talk to the other. No switch is available so it needs to be an ad-hoc setup.
I have a weird issue that I have not seen on any forum. My jaunty on DELL studio laptop seems connected to net, but I can not access any network service (ssh, firefox etc.). But when I connect a cable the cable lights blink as it should be and in wireless connection my wifi light blinks.
It was working 2 days ago without problem, and I have not done big changes recently.I removed and reinstalled network-manager and network-manager-gnome. Nothing changed. I see a message in each restart as follows (when Openafs is starting). I can reproduce it with "/etc/init.d/openafs-client restart"
ADVISEADDR:error in specifying interfaces: no existing ip interfaces found
a Netgear router with DHCP off at 192.168.0.1 my computer
eth0 at 192.168.0.2 wlan0 at 192.168.0.2
The wlan0 interface always connects to the router, while the eth0 interface connects to other computers with crossover and acts as a dnsmasq DHCP server for network boot and installation.
If I use the Gnome NetworkManager to enable both connections, that is, with wlan0 connected to the router/internet and eth0 to another computer, both as 192.168.0.2, I cannot access the internet while eth0 is connected.
Why is this? How can I configure my computer to follow wlan0 for Internet usage, but use eth0 for itself (the latter is working but blocking wlan0).
I have a rather urgent problem with my network, I got two virtual network interfaces one internal and one external. The problem is; I can't get connection to internet. The external NIC is set as a NAT and the internal is... internal.
My question is about TCP parameters in Linux. By now, I want to change the default values of:
Initial Timeout ACK Delay Idle Connection Timeout
I have a Linux Box with kernel 2.6.x and 2 ethernet interfaces. I know TCP is a stack that doesn't have anything to do with ethernet devices. Said that, the question: is there a way to set custom values for each interface? For example, a server listening to connections in eth0 would use one value for Idle Connection Timeout and another server listening to connections in eth1 could use a different value for that parameter.
I 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.
This 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.
For 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 > 22.214.171.124.47806: UDP, length 1400 ...
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 > 126.96.36.199.47028: 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 > 188.8.131.52.47028: 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 > 184.108.40.206.47028: 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?
In 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.
have 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: 220.127.116.11 = 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?
We 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.