Networking :: The Same Captured Frame Differs On Client And Server?
Oct 18, 2010
I am capturing the same traffic both on client and server. Using Microsoft Network Monitor on client and tcpdump on Linux server.
And when comparing the content of one specific frame captured on two machines, I see it different!
Precisely:
I have SIP communicator on client and opensips on server. Client is doing a REGISTER request to the server. This request contains "Contact:" header, which should contain an IP address of the machine.
When capturend on client, this header contains local private IP address of a machine with SIP communicator (which is 192.168.***). But when captured on server, this header contains the outer address of my provider's router.
I have 2 possible explanations:
1) Some unknown agent acting between my client and server
2) opensips itself is acting at a so low level, that the result of it's frame manipulation is visible by tcpdump.
I am interested if the second option is possible? opensips is a proxy, so does proxy able to manipulate frames directly in the medium?
If so, the is it possible to run tcpdump at a lower level, so that it see packets before opensips processing?
Installed Zend Server CE on 10.04 - install mostly fine. But phpmyadmin shows this error; "Your PHP MySQL library version 5.0.83 differs from your MySQL server version 5.1.41" I have followed the Zend online docs and used a DEB install. Why would these versions be different?how do I fix it so that the two are in sync?
I configured openLdap in RHEL5 on virtual achines,everything is working fine, I created a user called ldapuser,in LDAP server and i created a home directory for ldapuser in my LDAP client, now i can able to login to the both Server and client with ldapuser account....
Now here what am expecting is i want to export my server's home directory to the client, i dont want to create home directories manually in the client machine, i googled about that, and it can be done through autofs.....
what need to be done on the client and server side.
I have 2 ethernet cards but when I look at the Network configuration in "Hardware Tab" I have another acx wireless network. How to delete that because In my system Idon't have wireless card..probably installed before but want delete it now.
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then windows can ping server and resolve ip address and browsing Internet but can't ping [URL]... result is Request time out. ICMP already enabled in iptables.
How can I send already encapsulated Ethernet frame payload to server? Basically what I would like to do is to is route Ethernet packages I get from other peripherals to their needed destinations and packets I receive send to requested device on peripheral. Program will be running on BeagleBone Black with Debian OS. Steps program should do from my point of view:
# <IPv6<UDP<DATA>>> packet received on some peripheral (UART in exact case) sent to server requested by <IPv6> destination address field# <IPv6<UDP<DATA>>> packet need to be sent to server that server application would receive <DATA> extracted from IPv6 and UDP encapsulation# <IPv6<UDP<DATA>>> packet need to be sent to server that server would know that device which is requested is available in BBB local network# <IPv6<UDP<DATA>>> packet received from server would be sent to requested device
From what I already found out I need to add routing header to packet I want to send and pass it to MAC encapsulation layer, or there is service which can add routing header and pass to other layers for me?
Also how can I get data sent from server, since if I'm not very wrong, system should receive them also encapsulated in Routing header, not as RAW data payload.
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Multiple requests to my server, for totally random websites. I didn't even know it was possible to make those types of queries to a webserver. The only thing that is on the web server is a browser based torrent client. I have only shown a small snippet of the log file, but there are around 90k lines to different web addresses, from many different IPs. What I want to know, is what is happening? :S Why is someone querying MY web server, for web sites totally unrelated to it? And most of all, how can I stop it. My initial was to try and use iptables to block multiple requests from the same ip within a certain time frame, which I think would work as the server shouldn't really get many queries from external networks.
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Code: lspci and Code: iwlist scan
I briefly was able to share a folder in my Windows machine, and access it through my Ubuntu machine, after connecting both laptops with a cross-over cable. However, I can't even ping the Windows machine from my Ubuntu machine anymore, after trying to configure the IP addresses. I think I screwed it up.
Also, although this is not an Ubuntu issue, I have a weird Windows problem, where I can't access the Internet when both wireless and wired ethernet controllers are active at the same time. It would be a bonus if you could solve this problem too for me. I was surfing online for a solution to this problem for quite some time, but I was unable to comprehensively understand and implement what I browsed through. Also, some of the guides, like for example, that on configuring Samba, seem to be outdated, as the terminal tells me something like the package (that was required to be installed by the guides through sudo apt-get install) has been superceded. Hence I post here for clear, concise and easy-to-understand help from you gurus. It would be great if I could achieve the end result of being able to access the internet on my Ubuntu machine (through the Windows one).
I'm trying to synchronize a client with an ntpdate server. The ntp.conf file from the server has the following lines: # /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for
driftfile /var/lib/ntp/ntp.drift # Enable this if you want statistics to be logged. #statsdir /var/log/ntpstats/ statistics loopstats peerstats clockstats filegen loopstats file loopstats type day enable
How I am configure DNS Client and server in Redhat Linux 4 in my lab.I have total 5 computers and they are Lan connected.I want to make one of them server and the others are client.
I'm trying to setup a linux box to act as just a DNS server. Its something I'd like to use just for WAN type requests and leave other domain related things to the Server running WIndows.At this point on my Linux box, I can run queries and nslookups from it. I can not however, from a Windows box, run a NSLOOKUP command from the Linux box which is telling me to check the permissions from Linux to enable that for the clients. It's enabled.From a C: I type in nslookup - *ip of Linux box* and it tells me -- Can't find server name for address.
Running Linux Fedora 10 on an Intel Core 2 Duo PC. Runs great. We are trying establish VPN between a client and server on the same LAN. The network is a standard fast ethernet, run great. We are trying to install OpenVPN server, but having a little difficulty. Key and certificate builds seem to execute without a problem. But when we try to start the service we get [FAILED]. I've attached a copy of our procedure.
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in my office all users connect to internet via VPN.in our office there is one special server that we want when users connected via VPN,users can not connect to the special server and when users are not connect to via VPN can connect to that server.
From tcpdump, we see: 1. client SYN-----> server 2. server SYN/ACK---> client 3. client ACK ----> server 4. client data ----> server 5. client retransmit data some times ----> server 6. server SYN/ACK ----> client (weird, it look like server miss the step 3)
I have an Ubuntu server that is currently running Ubuntu 8.10. I was thinking of making it a VPN server for my iPhone and also for my laptop whenever I'm outside and need to access internet over insecure wireless networks. Now that part should be easy I found several guides on how to configure OpenVPN server, as well as enabling clients on iPhone, and OSX.
However, the things is that my server is currently a OpenVPN client also, I have a paid tunnel set up to bypass my ISP blocking incoming traffic on various ports. Is it possible to keep this setting but still enabling a VPN server? Essentially causing traffic from my external device to go in through my tunnel to the VPN server, and then out through the external VPN provider.
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The server has 2 NICs, one connected to the internet, and the other connected to the LAN. There is only one public IP. The computer I'd most like to connect to has a static, private IP. Anybody done anything like this or have any thoughts on how to get it to work?
I am facing connection refused error 111 in TCP client server program, in android native code which in C , but if code is in JAVA it works fine, but i want to continue in C only, in manifest file i have given permission and ip, port is correct .What am doing wrong?? or is their any network setting?? am using UBUNTU 10.04and If both client server Linux pc it works fine. only if android emulator becomes client then am getting connection refused
I have about 5 computers on my network that get their internet connection from a Linux NAT server.
192.168.12.02 is a Linux server that has a NAT set up to share the internet connection. 192.168.12.03 is a download server that is almost always downloading 192.168.12.05 - 192.168.12.20 is assigned by DHCP to users.
I want to make it so that the download server runs at full speed but is throttled only when someone from the user IP addresses range tries to use the NAT server.I think I'm looking for some way to set the download server's packets to have a lower priority than the client's packets. Is there a way to set this in the Linux server?
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As per the functionality of TCP/IP , when the server becomes unreachable for whatever reason , the client tries retransmitting the data till it can send the data or it timeouts. But in my above experiment using FTP , I can see that the FTP client is not trying to retransmit data at all . This I came to know using by sniffing FTP traffic at the client side. Is this expected or default FTP client available in Linux does not obey TCP/IP functionality properly ?
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The server is named alpha and is running Archlinux. It is exporting a directory named /files. The server is a couple of years old and I have accessed it extensively from clients running Arch, Suse, PCLinuxOS, and maybe some others, all with no problems. The clients (3 of them) are new installations of Linux Mint 10 (Julia). When I mount the nfs all of the nfs files are visible as expected. However, the owner/group is drastically different than on the server.
I might add that I have set up user id's and group id's the same. My user is 1003 on all systems, and the users group is 100 on all systems. When I am on alpha (via ssh), here is a partial file listing.
Code: [dick@alpha dick]$ ls -l total 9740 drwxr-xr-x 3 dick users 4096 May 16 2009 airplane -rw-rw-r-- 1 dick users 240978 Jun 27 2009 Alice Grad 1934.pdf -rwxr-xr-x 1 dick users 444 Jul 8 2007 alpha2ast -rw-r--r-- 1 dick users 444 Sep 2 2009 alpha2charlie
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If have searched the Mint forums, LQ forums, and google in general. I must be missing something in my search because I can't believe that no one else has this same problem and I am having it on 3 different boxes.
shed some light on what I am doing. I am wondering if I just havehings back to front.Server (MESH):Fedora 13Firewall ports open tcp 22(ssh), tcp 873(rsync)sshd service started
I'm carrying out a project for my university (CIT in Cork, Ireland) and I'm using CentOS running over WMware. I have a server and a client. The server has no GUI (command line UI) while the client has a UI. I need to install a Simple Forum Machine application and I'm told to FTP the files into the server. I figured out that the best option is to load the files in the client via the GUI and then ftp them in the server. How do I transfer the files from a the client t o the server using FTP? I'm totally new to Linux so the more details the better. Also I'm trying to mount a USB key on the server but have had no luck.
I'm using the Readhat Linux Enterprise 5, and I encountered a problem about captured keyboard need your help. I log in after entering the required username and password using keyboard, but then the keyboard is captured, i.e., I can not enter anything using keyboard. Meanwhile the mouse works well all the time. I encountered this problem when I pressed some keys wrongly two days ago, but unfortunatelly I can not find out these exact keys I pressed.
how to setup a home network for learning purpose. i have two laptops and a desktop connected to a modem-router for broadband (wired connection), i want to setup one as server and the others as client.
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I'd like to access a samba/SSH server which itself is connected to a VPN Server, therefore acting as a VPN Client. As soon as the VPN Connection is established, samba and ssh connections to this VPN Client get a timeout. But not all of them.
To get a better understanding I made an overview. The first one is a general network overview, without any VPN Connection, the second one with the VPN Connection established.
Network Overview without VPN I can access the server in several ways: *From the router via ssh (router runs ipcop with busybox) *From the laptop via ssh (putty via Windows 7) *From the laptop via samba *From the internet via ssh (port forwarding to the ssh server)
Everything is working as it should.
Now the server that runs ssh and samba service connects to a VPN Server on the Internet, this is also working fine. Now it gets weird. The only samba/SSH connection that is still working is ssh directly from the router to the server. Everything else gets a timeout: *From the laptop via ssh (putty via Windows 7) *From the laptop via samba *From the internet via ssh (port forwarding to the ssh server) Network Overview with VPN active
Why is that? It seems from the little understanding I have of vpn and networking, that incoming packages (like samba request from the laptop) don't get send directly back over eth0 but over the vpn connection. This seems somewhat logic, BUT ssh from the router is still working. Why from the router and not from the laptop? I really can't get my head around it.
Configuration Overview
tldr; One Client acts as VPN Client and samba/SSH Server. As soon as the VPN Connection is established samba/SSH stop working, but only partially.
