Ubuntu Networking :: LTSP Server - Routing Multicast Communications?
May 16, 2010
I'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?
I installed in Virtualbox many times and the clients would not connect. The config of the dhcpd.conf was the problem.Now, Everywhere I kept reading it said I had to turn off my hardware routers dhcp. Thats wrong, I have it working with it on and with one network card. Heres the nuts and bolts. Dlink 4100 hardware router assigning address block 192.168.2.200-250 to pcs on the lan. Router is set to reserve and IP for the ltps server nic so it gets the same IP assigned every time from the hardware router. No need to force linux to an ip when it can be set in the router. Then installed LTSP from alt-cd. Once done, dhcp wont run because it conflicts with the hardware dhcp. Found out by trying to restart it and it said stop - Fail when it tried to stop it.
sudo /etc/init.d/dhcp3-server restart So edit /etc/ltsp/dhcpd.conf. sudo gedit /etc/ltsp/dhcpd.conf
Mine attached below: The subnet, as long as the 1st three numbers match the rest of lan setup it will work.(192.168.2.0), rest of my lan is 192.168.2.x. Now notice the range is a different block than the hardware dhcp server uses. So all thin clients that connect will be assigned something 192.168.2.100-150 and all hardware connected pcs will be assigned 192.168.2.200-250 from the hardware router. So no conflicts. Then for the domain name server, set it to the hardware router ip. My hardware router is 192.168.2.2. Set option router to the same as hardware router of 192.168.2.2 Nothing in my dhcpd.conf file is pointing to the ltsp dhcp server. Nothing else had to be edited in the dhcpd.conf Next hurdle I had, after any change of the dhcpd.conf, ip's might have changed and you have to reconfig the ssh and the image. run these 2 commands.
sudo ltsp-update-sshkeys then sudo ltsp-upadte-image then sudo /etc/init.d/dhcp3-server restart
Then thin clients/lan boot pcs all can connect after that.
I have since installed again at work in virtual box, booted from another vbox client and booted from a separate lan pc. Then installed again at home on AMD 3200 Athlon, 1 gig mem. Booted from my main pc PhenomX4, no problems. Pc's must have lan boot available in the bios or net boot available on the network card(most consumer add on cards do not). But most motherboard lan connection do.
Currently have a problem with my LTSP server when using a gigabit switch with a megabit thin client.I am using K12LTSP with Fedora 9.The thin clients get most of the way through booting up then I get error messages saying:nfs: server 172.31.6.1 not responding, still trying.I don't get this problem if I use a 100 meg switch though.I have found several forum posts on the internet which all seem to point to the following webpage with a solution:However, when I make the recommended changes It doesnt make a difference.Below is an example of the default file located at /var/lib/tftpboot/ltsp/i386/pxelinux.cfg with its default settings:
I have an Edubuntu server with two nics joined to the primary windows domain and I can log on with domain credentials and everything is AOK. I used LikewiseOpen 6 to join the server to the primary domain. So, on my Edubuntu server eth1 is connected to the primary domain and has a static IP. eth2 also has a static IP and is the DHCP for the thin client subnet, connected to a switch. IP forwarding is enabled.
So far, so good: I can log on the thin clients with one of the local accounts specified on the Edubuntu server and with that account I can surf the net and, if I supply domain credentials, browse the primary domain. Problem I have is:
I can't work out how to log on to the primary domain with a Active Directory account directly from a thin client. If I try DOMAINuser to log on, after giving the password, the password screen refreshes and 'domainuser@11.*.21.*'s password' appears under the blank password box. The IP in that message is the IP for the subnet and not the primary domain. I feel like I'm miss-understanding some basic simple step but I just can't figure it out.
My 32-bit Ubuntu 9.10 [Karmic Koala] LTSP server has two NICs, one with Dynamic IP set by a DSL modem and the other with static IP of 192.168.0.254. I also have 4 thin Clients that boot from this server without any problems and another computer with Ubuntu 9.04 running some PHP programs with dynamic IP given by the same DSL modem. When I send requests to these PHP programs from thin clients, they all give the LTSP server's dynamic IP as their IP so I cannot trace who has sent this request to response back.
I actually know this is logical. Because the requests are sent by a program that's actually running on the LTSP server rather than the thin client. But my question is How can I run a program on a thin client with it's own IP? I also should mention that the dhcp3-server service running on the LTSP server has no conflicts with the DSL dhcp on the network and I know that the 4 thin clients get the IPs ranging from 192.168.1.101 through 192.168.1.104 from the dhcp3-server service. Because I can ping them while they're on. but /sbin/ifconfig on them shows info about the LTSP server.
I'm setting up an LTSP server using Ubuntu 10.4 64bit, and PXE connecting with thin clients using Atheros cards. The ltsp environment is 32bit.
Unfortunately I get an error message with "No interfaces found! Aborting..." and a kernel panic early during PXE boot.
After an enormous amount of investigation, I've narrowed it down to (probably) being the fact that the ltsp chroot environment doesn't have the correct driver for my network card (I believe it's atl1c). The correct driver IS available in Ubuntu, though, as I can successfully boot the thin client from both 64bit and 32bit live CDs and bring up the network interface.
how can I install the correct driver in the PXE environment?
I am wanting to set-up serial communications between my server (ubuntu 9.04) and a picaxe chip (a pic with a bootloader) I need to send data in the format of "1,1,1" or "1,1,0" at 9600 baud 8 data bits, no parity, 1 stop bit and no flow control. the data must be sent as numbers not ASCII I have tried Code: echo 1,1,0 > /dev/ttyS0 Any simple shell script or even python.
I have a server that has two NIC cards installed eth0 and eth1 we use a linksys router (192.168.2.1) which runs DNS for our LAN. I have installed Squid on the server which runs Ubuntu server (8.04 Hardy) w/ GUI. I can surf the net on the server with google chrome configured to use proxy server localhost:3128...works good. The router is wire directly to eth0. I have my laptop (running Ubuntu Hardy) wired to eth1 and I want to be able to surf the Internet through my server. From my laptop, I can ping 192.168.2.100 which is the IP address assigned to eth1[?] by my router. I assume I need to establish a route from my laptop to my server. I would like to archive this via the CLI and I am not having any luck thus far. If I add static IP addresses to eth1on the server and eth0 on my laptop will this simplify the process? How can I add a route which will allow me access to the Internet via my laptop?
Server: Code: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eth1 0.0.0.0 192.168.2.1 0.0.0.0 UG 100 0 0 eth1 0.0.0.0 0.0.0.0 0.0.0.0 U 1000 0 0 eth0
ifconfig eth1 on the server: Code: eth1 Link encap:Ethernet HWaddr 00:30:48:85:cc:1b inet addr:192.168.2.100 Bcast:192.168.2.255 Mask:255.255.255.0 inet6 addr: fe80::230:48ff:fe85:cc1b/64 Scope:Link Up Broadcast running Multicast MTU:1500 Metric:1 RX packets:7701 errors:0 dropped:0 overruns:0 frame:0 TX packets:7898 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:5572718 (5.3 MB) TX bytes:1506869 (1.4 MB) Base address:0x9000 Memory:ef400000-ef420000
i know exactly what i need to do, im just not familiar enough with command line to do it properly.i have 7 computers.the first 4 are connected to a router via wireless at one end of the house. of the last 3 only 1 will be able to access the router via wireless, so it needs to share it's one wireless connection via ethernet. this computer i'm going to call 'server'server will have two IP'swlan0 192.168.1.6 this connects to the router that has internet access.eth0 i intend to have the following settingsip:192.168.0.1sub: 255.255.0eth0 will connect to a second router, where the cat5 cable goes from the server, into the internet port of the router where i will define the router's static IP:IP: 192.168.0.100sub: 255.255.255.0gateway 192.168.0.1i have then set the router IP for LAN handling as 192.168.27.1 and all ethernet connections will have a 192.168.27.x IP.
so i need to know how to, without a gui application, use the terminal to assign server eth0 a proper IP address, and tell the server to take the connection it has and share it through eth0 to supply internet for the last 2 computers via ethernet.i had it set up in this way with a windows machine being the one that had the wifi access, but i'd rather have it setup for the ubuntu server to do this task. security is imperative for these 3 remaining machines, so just getting 2 more wifi adapters for a connection to the initial router isn't an option.the 2 that connect to server do so through SSH and though server IS connected via wireless it only makes outward connections through
I have one main subnet 192.168.50.0/24 with a defaultrouter 192.168.50.1 connected to the internet. I have an NFS server on that network. Everything is working as desired and machines are able to see each other and access the internet.
Now, I would like to add two more interfaces to the NFS server (running Slackware Linux), each on its own different subnet, say 192.168.51.0/24 and 192.168.52.0/24. The clients on those new subnets should also be able to access the internet (through the router 192.168.50.1). how to setup routing? Do I need any additional hardware router in between, or just a software configuration on the NFS server?
On a side note I have VLAN capable switches (couple of ProCurve 1800-24G) and would like to separate the three subnets using VLANs instead of using three separate switches.
Location A: Internet -> ISP 1 -> Firewall 1 (external IP address) -> Web Server 1 (internal IP address) Location B: Internet -> ISP 1 -> ISP 2 -> Firewall 2 (external IP address) -> Web Server 2 (internal IP address)
I want to find out if I can failover to another location without having to make changes on the DNS server. Just by redirecting traffic from ISP 1 router to ISP 2 router.
i have a Server, which has 2 nics installed. Each of those is connected to a router, which is connected to internet. On the server, i have apache, maillserver and im-server running. On the other hand, also squid, dansguardian and clam are running. so now: via eth0 i would like to have just the traffic, which is requested from outside (the big bad internet..) to my server (apache, mail, etc). via eth1 i would like to have all OUTGOING (also to the big bad internet) from the server, which is requested by a internal client. And of course all requests to my own server
both nics shall route their traffic to their own router. For better comprehension please consult the enclosed graph. Until now, i did not find a good solution, the default route is set to the traffic from eth0, if not, no external request will find back to a client do you have a idea how to handle this the easiest way?
I am having trouble for routing port 80 from a Billion adsl modem to a guest server in VirtualBox. There are quite few different changes from my last setup so I kind of confuse which one is wrong.
I used to use have the setup belowusing modem Linksys WAG354G use static ip 192.168.1.100 for my machine use static ip 192.168.1.102 for my guest VirtualBox server guest OS is serving http listening on port 80 i use bridge from my host OS for VirtualBox set my modem to direct all traffic on port 80 to 192.168.1.102 host OS was Fedora 11
now I useusing modem Billion 7404VNPX use same static address and configuration host OS is Fedora 13
main issue is I cannot reach the guest OS if I navigate to my modem ip address. (e.g. http://192.168.1.1) if I change the modem to direct all traffic to my host OS ip address (192.168.1.100) it works nicely.
I have tried to disable and enable the firewall without any luck.
I have set up a Virtual machine on a dedicated server from 1and1. I hoped to use a bridge to give the vm direct access to the internet but 1and1 do mac filtering and so the only option is to use NAT.
I used Virtual Machine Manager on my Ubuntu 10.04 machine at home to install Debain Lenny on the vm on the server using KVM and all went well. I put it on a virtual network 192.168.100.0 and i can access it from the host and i can access the internet from the guest using NAT that libvirt set-up.
I bought another ip address from 1and1 with the hope of forwarding packets to the new ip address 11.22.33.02 to the guest vm.
I have tried all sorts of routing rules using iptables without any success.
my virtual network is on virbr1 the guest ip is 192.168.100.50 my external network device is ip say 11.22.33.01 on eth0 with the secondary ip say 11.22.33.02 on eth0:1
Here are the latest rules i tried:
Quote:
iptables -t nat -A PREROUTING -d 11.22.33.02 -i eth0 -j DNAT --to-destination 192.168.100.50 iptables -t nat -A POSTROUTING -s 192.168.100.50 -o eth0 -j SNAT --to-source 11.22.33.02 iptables -A FORWARD -p tcp -i eth0 -o virbr1 -d 192.168.100.50 -m state --state NEW -j ACCEPT iptables -A FORWARD -t filter -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT
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.
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 > 224.16.17.23.47806: UDP, length 1400 ...
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.
If 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?
I setup Ubuntu 10.10 (edubuntu) along with ltsp. I have an environment with a windows network (192.168.1.0) and a subnet (192.168.0.0) that the new terminal server is on. Everything seemed to be connecting properly, but when I attempted to boot the first client, I get the error message: "Cannot connect to NBD server".
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
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: 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?
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.
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'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.
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.
I 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
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.
