Ubuntu Networking :: Internal DNS - Ping Host On LAN?
Dec 28, 2010
If I try ping a host on my internal lan from my ubuntu notebook the host name never resolves, but if I ping www.domainname.xxx it will resolve because our dhcp server is setup as the dns server too. If I use the connect to server tool and select samba share and specify host by name, it can resolve that and the shares show up... same dns server, same machine, but different interface/program. My real reason behind this is because my synergy+ keeps falling over whenever the synergy servers dhcp lease expires and it gets a new I have to then specify the new address and change configs.
Everything is working fine and CLIENT A can talk to CLIENT B and vice versa, with only one problem - CLIENT A cannot ping 10.10.30.1.
I checked routing several times, there is no NAT and firewall is disabled on the SERVER.
CLIENT B can ping and access any device in the diagram. CLIENT A can ping and access any device in the diagram too, however cannot ping eth1 of SERVER (10.10.30.1). ROUTER can ping any device in the diagram except eth1 of SERVER (10.10.30.1).
If I launch 'ping 10.10.30.1' from CLIENT A and run tcpdump on SERVER eth0 I see no hits at all. If I launch 'ping 10.10.30.1' from CLIENT A and run tcpdump on SERVER eth1 I see ICMP requests coming from CLIENT A but no replies.
It doesn't look like a routing problem because clients A and B can communicate with each other. Also, we have around 20 similar installations but this is the first time CLIENT A cannot ping internal interface of SERVER.
I am a new user to Linux but in the last couple of months gained some Idea about it,I am trying to set up a small network in my office having 3 windows xp PCs, two fedora10 PCsI have an adsl router with 4-port hub connecting to the internet, one switch (say sw1) and one linux PC (say linux1) is connected directly to the router, the three win xp PCs are connected to switch sw1.all the above is working fine, I am able to get connected to Internet In all the systems, and able to network among all the above four.Now I want to make the linux1 as a proxy server for, hence I added another network card into it connected it to another switch sw2, which is connected to another linux pc (say linux2).
I have tried a hundred things, and googled an equal no. and finally posting it here.In order to reduce confusion I have disabled DHCP in all machines, and given static ips insteadNetworkManager was not happy about it, hence to fix my static IP i disabled NetworkManager ('chkconfig NetworkManager off')
I want to ssh to a pc in our home network. It is a standard network in terms of a DSL router, dynamic IPs via DHCP, WPA2/PSK security, wireless network connection for all pcs except one which is wired to the router.I got the error "no route to host" from ssh. Openssh-server was already installed. It turned out later that the laptop I want to ssh to (namely the one which is connected by cable) cannot be pinged by any other laptop on the network.
The pc in question (lucid lynx with most recent updates) is online, can ping itself and the router, but cannot ping others in the network and cannot be pinged by them. I suspect a firewall setting of being the problem.
Basically, I have a windows 2003 server virtual machine (vmware) inside Ubuntu 9.10.
The Ubuntu machine has IFconfig: Code: sam@sam-laptop:~$ ifconfig eth0 Link encap:Ethernet HWaddr 00:15:c5:b8:c8:8b UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) Interrupt:17
Why can't I ping or simply access the internal server on my ubuntu machine from a another computer on the 192.168.1.0 (slash)25 physical network? Do I need a bridge? Iptables?
I am using ubuntu 9.10 and I still cannot figure out this thing. I work behind a proxy managed by my university. Now, I cannot ping the other users on my network although they can ping me. Not to mention, I also cannot ping [URL]... It says : ping: unknown host [URL]... But I can ping the proxy server.
I have a somewhat complicated network setup that I am testing on an internal network. I have the following route setup:
PC Client (192.168.2.100) --> Router (192.168.2.1) --> DSLAM (on our internal network) --> PPPOE Server (192.168.9.1) on Linux Ubuntu 8.04 on interface card eth2.
On the same Linux Ubuntu Machine on interface card eth1 (static IP 192.168.5.100), I have an Asterisk SIP server plugged into it. SIP Server = 192.168.5.101 (static) I need the PC client (192.168.2.100) to register via SIP soft phone to register on the SIP server (192.168.5.101). From the PC client I can ping as far as the eth1 interface (192.168.5.100)...but cannot ping the SIP Server (.101).
From the SIP server (192.156.5.101)...I can ping 192.168.5.100, I can ping 169.254.5.228 (Eth2:avahi), but not sure what that is. I cannot ping the pppoe default gateway (192.168.9.1), which I think you cannot anyway. No firewalls are running. My IPtables I cleaned out totally. I think it might be as simple as a route add, but I really have no clue. Tried building a virtual bridge using brctl LINUX betweeh eth1 and eth2, but that made things worse (could not ping anything after that)
I made an ip packet using raw sockets and used icmp header of echo request inside that ip packet.I have a wifi lan with 2 host(laptops) connected to it. when I send the packets to any of these host the reply me with echo reply as i see in wireshark. but when i change the source ip and mac to that of another host there is no echo reply packet in the network but only echo request packet is there. Can anybody tell me why is this happening. and am also using Promiscuous mode so non of the packet is discarding.
I have a server that I can ping, and I can connect remotely with ssh to it. But when I try to connect to apache (port 80) I get "no route to host". But I can connect to localhost It's not just my client system that is having this problem but also systems that are on the same subnet There is no firewall running on the server route on the server
I am working behind a http proxy (172.30.x.x:3128). I have configured it in my terminal. All the applications such as wget,lynx firefox etc. are working correctly.However all dns utilities like nslookup, host and even ping too are not working.Following is output of host command:
Code: root@ding:~# host google.com ;; connection timed out; no servers could be reached Output of host -T:
[Code]....
To connect to net I have to first run dhclient3(learnt from this forum!).It gives me my ip but where is dns address sent I don't have and idea.
I've encountered a problem after doing a fresh install with xubuntu 10.10 (2.6.35-23-generic).some sites are blocked like [url]....if I do dig [url]....- I receive the A, CNAME records and the IP address and everything.when ping[url].... - I receive 'unknown host'.when ping <theipaddress> - I receive responses
I just set up my first ever bind9 DNS server running on ubuntu server 10.04. This server is also my gateway/dhcp server.
Here is what is weird: If I do a dig @8.8.8.8 dschuett-lmtl.scs.local from any of my clients it resolves?!?! Dig shows that it got the answer from MY Bind9 DNS server (and NOT Google's of course), but why is it still resolving when I'm telling it to use and external DNS server?
The other weird thing is that the SAME EXACT dig command above does NOT resolve internal host names if I do it from the Bind9 DNS server. - Which is what i would expect SHOULD be happening if done from the client machines...
I had configured Squid in RHEL 5 and facing an issue with pinging. Not able to ping any website,hostname is resolving to ip address but not able to ping
A brief description of my network:It is a small home network consisting of an Ubuntu 10.04LTS server edition, an Iomega ix2 NAS, a WinXP pro server and several family laptops.This is all routed through a Netgear WNDR3300 home router. All are assigned IP's via DHCP and all but the laptops are static (via DHCP though). The WAN address/DNS is assigned via DHCP from my ISP.The problem:When one of the machines is offline, Ubuntu does not resolve the netbios name correctly. No surprise here. But what is happening is that it is finding some arbitrary machine on another network. Below is what a ping to an offline host reveals:
I can ping a host on my LAN successfully, but I cannot ping [URL]... for example. I have disabled the firewall and set http_proxy and can browse the internet with "Use system proxy settings" checked in Firefox. I am unable to update with yum either, but I am not sure if this is a side effect or not. I have run a trace on my ip address as I am browsing the internet and I can see the sites I am visiting on our web appliance. However, if I try to ping or update no requests are hitting the proxy so I don't think that is the issue.
I have a machine running linux with 3 ethernet interfaces attached.
My Ifconfig:
My route output:
eth0 is attached to a laptop, eth1 is attached to a PC. eth2 is attached to a DSL modem, and the server is successfully acting as my internet gateway. The trouble is, my PC cannot see my laptop and vice versa. E.G. cannot ping, host seems down.
This is a RHEL 5.4 install. I did a fairly routine install setting up a static IP address of 10.5.96.10, a subnet mask of 255.255.254.0, and a gateway of 10.5.96.1 with the standard DNS setup for this network. These are all standard network setting for this network and otherwise work fine on other systems. The IP, gateway, and subnetmask all appear correctly on all relevant configuration files. This server can not ping any other system on the network and can not ping its default gateway. No other systems can ping this one either. Also this system can not ping "localhost" or its own hostname. The hosts file contains the line:
[code]...
I can ping 127.0.0.1 and 10.5.96.10 and it works fine. Also the firewall is disabled. I know I probably can't get a straight forward fix with the information I have on hand right now, I'm more of a Debian guy, so there might be some Red Hat intricacies I'm not familiar with. I think I had a CentOS install some months back that had this issue and I don't remember how I fixed it, or if I even did. I might have just replaced it with Debian. That's unfortunately not an option this time around since it's not my box.
My Ubuntu Box has 3 interfaces. eth0 (Internal 192.168.1.0/24)eth1 (External ISP DHCP)eth2 (External ISP Static IP)I need the outgoing traffic to internet for 1 of the internal pc (192.168.1.10) to only go only go through eth2
I am using an virtual machine. where I need to ping from one machine to another. earlier I was able to ping. But after going to google.com once, I cannot ping back to this machine.
But if I gave ping -I eth1 <IP> then I can ping.
I cannot install any package, so tell me solution which includes not installing any package.
Both systems connected in same LAN based network . Both WAN live ips are connected through different modems. Problem is that , no system is able to ping or connect with other system with Live ip , though they are able to connect through LAN ip and both systes are accessable and also able to browse internet (google etc..) Ping error :-- Destination Host Unreachable.
i have installed virtualbox on centos , and installed xp as a guest os. my LAN is on 10.200.2.x/24 network inorder to avoid conflict i have given centos ip as 10.200.2.191/24 and a virtual ip 192.168.56.4/24 my gateway is 10.200.2.1 i am able to ping from my guest os to host os the ip address but not the gateway inorder for internet connectivity
Not sure if this post belongs here, but here it is.
Host: Win server 2003 Guest: Ubuntu server
Host: IS able to ping guest. Firewall is OFF. NOT able to access guest (which is a web-server) at browser. Guest: NOT able to ping host. Running a web server, you can check the website: (pegajosa.com) is running under that virtual Linux server.
Problem: guest needs to access host's sql database and/or any resources.
I have VirtualBox v3.1.0 r55467 running on f12 2.6.31.6-162.fc12.i686. The guest is Windows XP SP3. I need to enable bridged mode for the virtual network interface on the guest. Everytime I enable bridge mode the following error occurs.
Quote:
Failed to start the virtual machine Windows XP. Failed to open/create the internal network 'HostInterfaceNetworking-wlan0' (VERR_SUPDRV_COMPONENT_NOT_FOUND). One of the kernel modules was not successfully loaded. Make sure that no kernel modules from an older version of VirtualBox exist. Then try to recompile and reload the kernel modules by executing '/etc/init.d/vboxdrv setup' as root (VERR_SUPDRV_COMPONENT_NOT_FOUND). When I run '/etc/init.d/vboxdrv setup' i get the following compilation error:
Quote:
Stopping VirtualBox kernel module [ OK ] Removing old VirtualBox netadp kernel module [ OK ] Removing old VirtualBox netflt kernel module [ OK ]
[code]....
dmesg gives me nothing. I have scoured the web .. and even asked on #vbox and #fedora cant get.
I need to allow ICMP ping for one host only. I found out how to enable it to all hosts (ICMP Filtering, check ping) but I would like to reduce the scope to one host. I know I can add rules in the user_post script but I can't find the correct iptables command ...
