Ubuntu Networking :: IP Address - No Responses Received For Pings
Aug 6, 2010
I am having (seemingly) random trouble with my wired network ever since I installed Lucid. I have no problem getting an ip address from dhcp. However, randomly the computer will boot and although I have an ip address I do not receive any responses for pings on the network nor can I browse the web. If I sudo /etc/init.d/networking restart a few times (or reboot) it will start working. However, restarting the networking services (as mentioned above) again will cause me to no longer receive responses for pings or browse the web.
Furthermore, I have never been able to successfully ping if I manually set an ip address. I have un-installed network manager and I am using /etc/network/interfaces to configure the network. Using Lucid Lynx 64bit on a Dell Precision. I have pasted below the output of a few working commands. When I switch between static ip and dhcp I am commenting/uncommenting the lines shown in /etc/network/interfaces.
I installed the Centos 5.5 and after the Xen. After I put a virtual machine named VM01.Initially it worked properly, I tried everything and it worked.When rebooted, I had problems with the network.I have two network cards eth0 and eth1, but eth1 does not have any ip and I use only eth0.The error that appears is:
vif0.0: received packet with own address the source address
I've been trying to use MySQL in Ubuntu but I've been having some connection issues and in trying to troubleshoot that, I observed this strange behavior with pings in Ubuntu Desktops inside our network.
- All Ubuntu Servers we have (10.10 and 8.04) behave as expected - All Windows machines behave as expected - All 5 Ubuntu Desktops we have, (10.10 and 9.10) exhibit the following unexpected behavior:
If they have a local ip addresses and are connected within the internal network, either to a switch or directly to a router, pings take much longer to be sent. It's not a higher lag, it's the time between each ping that increases. I have to wait for around 5 seconds for each ping, but the time in the ping reply is less than 100ms, also they're all in order so I assume it's the system delaying the sending of each ping.
If I plug a USB 3G modem directly then it works as expected again (~1 sec between each ping sent). Is this an intended feature, that depends on the network environment, or is this something I should look into more closely?
I have an asus router running tomato firmware. Through the webGUI I have set up an openVPN server as per the tomato guides. I am using the network manager plug-in in ubuntu 10.04 to connect as a client to the tomato openVPN. All of my certificates seem to be set up and working correctly.
I am able to successfully connect to the openVPN server using the ubuntu client but after that I get nothing. On the client side I am unable to ping the router, any ip addresses inside my private network, the virtual network ip, and web browsing (client) no longer works.
Also, when connected I am unable to ping the client from the private network.
Code: chris@ChrisLaptop:~$ ifconfig eth0 Link encap:Ethernet HWaddr 00:1e:68:90:5e:e9 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0
Several days ago responses to many, but not all, of my internet requests slowed from long to never.I'm on Verizon FIOS; running Firefox on a Debian Lenny system with 6GB or RAM and 500GB HD with 32GB cache.
internettrafficreport.com shows index of 84 for North America. I've pinged a few sites -- see returns from 16ms to 91ms.I've also rebooted my Verizon DSL router.
Brand new network, just installed, all ubuntu 9.10 boxes connected to a Dell 2206 dumb gigabit switch, and from there to Dlink router to cable modem. Pretty simple. ISP confirms great link out and inbound,
However, http requests can sit for 20-30 seconds (sometimes longer), before content returns, same for pings.
Some thought it might be MTU-related. What is best MTU setting 1500/1492/ ?
Host machine is a "2.6.32-24-generic-pae #38-Ubuntu" and VMware Workstation version is 7.1.2 build-301548.In addition to those three IP addresses(192.168.1.254/24, 192.168.1.68/24 and 192.168.1.221/24) seen on a drawing, there are four identical virtual machines inside the 192.168.1.68/24 machine. Virtual machines are named Olive0-3. Olive0 has IP address 192.168.1.100, Olive1 has 192.168.1.101, Olive2 has 192.168.1.102 and Olive3 has 192.168.1.103.
I have a Slackware 13.0 server that is not replying to icmp pings. However, I have double checked that /proc/sys/net/ipv4/icmp_echo_ignore_all is set to 0. The weird thing is I can run nc -v slackware 22 from any computer on my lan and the banner comes up just fine. The nic is on the same netmask and broadcast as all the other computers on my lan. I can log into it as well, it just doesn't respond to pings. I can even ping other computers and get replies just fine when pinging from inside the Slackware server.
I have even added an iptables INPUT rule for -p icmp -j ACCEPT. Although I've never had to do this. I ran tcpdump -vv icmp and I can see ping requests coming into the computer, however slackware simply doesn't respond. What could be causing this? A corrupt arp cache? It's been happening for more than a few hours so I wouldn't think so. How can I view the arp cache table? How do I clear it?
Back in April I set up a Ubuntu DHCP server and a multiple VLAN network [URL] to migrate our various servers, workstations, etc off the 192.168.1.1 /24 network that everything was on because we where running out of address space. I built out the new network and everything worked great except our AD server would never get an IP address from the DHCP server (static reservation) and even if I set the IP statically on the AD server it couldn't ping the gateway and noone could log in. After several attempts to resolve this, including bringing in outside help, we where never able to figure out what the problem was.
Now 6 months later I have time to revisit the issue without effecting the live network. I used Acronis and imaged the AD server last Friday, cloned it on to another box with the same hardware, and put it up on the new network that's been sitting unused for the last 6 months. Today when I statically set the IP on the AD server (which is what I want) it connects and I can ping it's gateway 192.168.1.1 and all the way across vlans to a test sales agent workstation at 192.168.8.xxx on vlan 800 but only if I statically assign the agents station an IP address. When I try to get an IP address via DHCP it fails as destination unreachable. Nothing has changed in the last 6 months on the DHCP server but now it for some reason can't ping its default gateway 192.168.1.1. All of the config files are the same as they where left from the post linked above aside from the vlan id's used where changed from 1's to 100's (i.e. vlan 3 is now vlan 300) /etc/network/interfaces
auto lo iface lo inet loopback auto vlan100 iface vlan100 inet static
why it can't reach the gateway, when I do a tcpdump I can see the DHCP requests come in on eth0 but the server never responds and I'm pretty sure its because it isn't "seeing" them since it thinks there isn't a network connection but I don't know how to trouble shoot to find out where the problem lies.
I've got a machine running Ubuntu Server that is on several VLANs. Each VLAN has its own subnet and the server has an address on each subnet. The switches are set to allow tagged traffic to the server for each VLAN that it is on. Switch ports ending with workstations are given untagged ports on whatever VLAN is appropriate. Workstations are given addresses on a subnet for each VLAN via DHCP. All this works great and hosts on any subnet/VLAN can access the server as normal via its address on that subnet/VLAN.
Accessing the machine by its address on a non-local subnet is where I run into a problem. Inter-subnet traffic has to go through a router, which has been set up appropriately. Running tcpdump on the server and pinging it from a workstation on a subnet, using its address on a different subnet, shows the server receives the ping, but sends no response:
Code: sudo tcpdump -i vlan4 -n tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
I am new to Ubuntu almost installed it after windows showed blue screen 4 ever n ever. However after installing ubuntu whenever I log in windows it doesnt detect any network connection but when I use Ubuntu it automatically does can it be that Ubuntu is causing any problem? And how to check how many packets are being sent and received through my wired network and do I have to install any drivers for my modem in Ubuntu.
This has been bugging me for quite a long time. I need to have a pptp connection to my university. I have tried to locate the error, but this has been a real trouble.
A little bit of history: My girlfriend had a laptop with M$ vista on it with a working PPTP connection. I had a laptop with Ubuntu, with which I couldn't get the PPTP working.
When my laptop crashed, I bought a new one on which I run a dual boot XP SP3 and Ubuntu. I also own a desktop (Dual M$ Win 7 / Ubuntu standard Karmic) and my girfriend also upgraded to Win 7.
Currently, the XP version is the only one on which I can get a connection. Both Ubuntu and the Win 7's give me a GRE proc 47 not received error. I know our router (a DAVOLINK DV2020) is notorious for not sending through GRE proc 47, but this either shouldn't be the case or it shouldn't matter, since I can make a perfect connection through the XP OS.
This is quite a handicap, since we both study at the university for which we require working VPN PPTP connections.
I was wondering if there was a Windows or Ubuntu way to limit the amount of data that is able to be sent over the internet between certain times, eg. Between the times of 7am and 7pm can only download 300 MB from the web, when this limit is reached the web is either disconnected or slowed down.
Currently my OS is Ubuntu 9.04 Jaunty Jackalope Desktop OS and my web server is Apache2. I have a public address 60.x.y.z and my pc local address is 10.x.y.z. I have a web app in my Apache2 which currently run in localhost(10.x.y.z).
I would like to enable the web app so that it could be browse from outside. I know there maybe some port forwarding process and some commands involved in order to do that. But I have no idea on the steps to do that.
I set up environment according to BareMetalProvisioningBestPractices document, I think everything should be ok. Now trying to plug in new virtual machine for PXE install Linux. But something is wrong, DHCP waits couple of seconds, and then I receive:
PXE-E53: No boot filename received PXE-M0F: Exiting Intel PXE ROM.
I think, all services required are started.
dhcp.conf on boot/stage is: # # DHCP Server Configuration file. # see /usr/share/doc/dhcp*/dhcpd.conf.sample #
pxelinux.0 was taken from RHEL4, but I've got image and trying to boot RHEL5. Maybe there is something?
Version 10.04 LTS. Installed desktop version and network worked but I needed a static IP address and the install configures for a DHCP configured address. I tried changing to static address using the System->Preferences->Network Connections application but was unable to get the system to come up with the network up.
So I manually modified the /etc/network/interfaces and the /etc/resolv.conf files. I restart the system but when I do an ifconfig, I don't see a configured IP address on eth0 (only the loopback address). If I run /sbin/ifup eth0 everything then works fine and ifconfig shows the correct address bound to eth0.
I'm running Ubuntu 10.10 and I'm having problems trying to assign it a static IP address. No matter what I put in the Preferences->Networking area (identifying the interface as Manual)... it still will query DHCP for an address if I run the dhclient command. I'm using to using ubuntu server where I just set the IP in the interfaces config file.
I used to connect to the internet via a Linksys router using the following terminal commands (Network Manager has never worked for me on any Ubuntu install):
sudo ifconfig wlan0 down sudo dhclient -r wlan0 sudo ifconfig wlan0 up
However, I recently changed the old modem + router for a new wireless modem (a Thomson TG585v8 ). Now, the result of that last command is this:
amosupremo@amosupremo:~$ sudo dhclient wlan0 Internet Systems Consortium DHCP Client V3.1.3
No working leases in persistent database-sleeping. I've tried to connect in Natty(both Ubuntu and Kubuntu) and it's not working either.I also purged Network Manager and installed wicd and I managed to get an intermittent, slow connection.
1 ) Machine Brand and Model (PC/Laptop): No brand. I built it with the following specs:
AMD Athlon II X4 2.6GHz 2 HD: 100GB Sata (Ubuntu and XP64 install) / 80GB IDE (XP) 4GB RAM Gigabyte Motherboard
2 ) Wireless Brand, Model and Wireless Chipset:
amosupremo@amosupremo:~$ lsusb Bus 002 Device 005: ID 0ace:1201 ZyDAS 802.11b Bus 002 Device 004: ID 049f:000e Compaq Computer Corp. Internet Keyboard
3 ) check interface:
amosupremo@amosupremo:~$ ifconfig wlan0 wlan0 Link encap:Ethernet HWaddr 00:02:72:04:d0:04
I am also attaching the wicd log. It contains a session where I got the intermittent connection. I stopped that connection and restarted it (with the same results) two times.
i am using centos 5.2 . recently i have implementing transparent proxy but i faced issue. i received lots of messages in dmesg. i have 2 machine with same OS another machine are works fine with this same configuration
br0: received tcn bpdu on port 1(eth0) br0: topology change detected, propagating br0: received tcn bpdu on port 1(eth0) br0: topology change detected, propagating br0: received tcn bpdu on port 1(eth0)
I am working on implementing a protocol on NS2.34 .I really need help to solve this problem . Actually , I don't now whether the problem is generated by the tcl code or the c++ code when I run the simulation, I get this result :
Code: num_nodes is set 64 INITIALIZE THE LIST xListHead 34 45 channel.cc:sendUp - Calc highestAntennaZ_ and distCST_ highestAntennaZ_ = 1.5, distCST_ = 550.0 SORTING LISTS ...DONE! code....
where packets are stored when they're received. After some googling, I think perhaps libpcap with mmap would be the solution. Does libpcap 1.0 and above support mmap?From my understanding, mmap would allow me to directly access the buffer without having to explicitly copy the packet to another buffer for me to do processing. I would also appreciate it if someone can let me know where I can find examples of such applications, as many examples of mmap I've found involves mapping a buffer for file operations, rather than integrating it with pcap functions like pcap_loop, pcap_next_ex etc.
I have a Webserver (Co-Location) and all runs fine ... since last week. Now there are a lot of RX-ERR shown in netstat and ifconfig. And when I try to upload a external website direct on the server for example via wget, it is very very slow and hangs very often.
I have analyse the network but I was not able to find a problem. My hoster has checked the network and all looks fine. For example my hoster has plugged-in a pc in the same switch ... and was able to do wget (load external data, like websites) in normal speed.
Since last week my websites were delivered slower as before, too. It seemed there is a network-problem ... but how can I find it?
Actually I can install moduls ... but the server needs hours. So, if you knows a good command-line tool to analyse the network.
I am running my own Postfix mail server. Some time ago I noticed that most email was rejected because of the server's dynamic IP address. So I got a fixed IP address. However then I noticed that some mails got rejected due to failing the reverse DNS check. So my ISP told me to get a range of IP addresses and they could then create a PTR record for one of those addresses. That is now running but it turns out that the IP address used for the PTR record is a ... dynamic IP address. So Spamhaus PBL rejects my emails again.
In my job I use some ethernet embedded devices. They take an ip address from dhcp server or auto ip. I only know mac address.How can I obtain ip from mac address? In other words I need a rarp packet generator.
PC1 runs radvd to provide router advertisements to the network and a DHCPv6 server for stateful addresses.Each interface is configured on a separate subnet. PC2 runs a DNS server on eth0. PC2:eth1 is used as an IPv6 client for testing purposes. The connections from PC1 to PC2 are just crossover cables.I've created virtual machines of both PCs and have created 4 virtual adapters on the host machine for each of the local-only interfaces.Now I have this:
I have a few external IP's assigned to me by my ISP. I have IPcop as my router/firewall. I am wondering how to bind 1 of my external ip's to my internal ip address. So I do not have to port forward, etc. For Example, 220.127.116.11 to 192.168.1.123 and on the server it see's the external IP address.