In order to debug a problem, I want to list down as many as possible reasons of a server (SOAP server running on Fedora 10) sneding RST in middle of packet transfer. Please note that in my case, SYN and ACK of initial handshake went through. Server received request from client and started data transfer but then suddenly, server sent RST in between data transfer.
View 4 Replieswe have a minor issue with time synchronization in proprietary equipment.the client needs to synchronize time with server, but not using NTP.it is not very important so doesn't need to be done often.the problem is that it won't synchronize. I can see the server is sending tcp packet with date&time, but the client ignores it.I suspect the problem is in format (manual specifies there are two possible options like MM: DD: YYYY and so on, but server seems to use some other)Is there an easy way to run some program in Linux Debian, to send that simple packet with correct date?
View 4 Replies View RelatedI'm implementing static IPv6 address on two Fedora 13 installed hosts. These two computers are connected using a switch between them and I use D-ITG to generate traffic in the network.I need to send packet from host1 to host2 using this command and I got permission denied
Code:
#./ITGSend -a 2001:db8:c003:111e::3 -T UDP -x recv_log_file -t 30000 -c 32
Connect error in createTransportChan(): Permission denied
[code]....
I am trying to design an application which violates the DHCP. Specifically the difficulty in writing this application is physically sending the raw packet. I need some documentation on either a library that supports this or where to look for support for raw packet creation. I am not trying to create a raw datagram, that doesn't meet my needs because a raw datagram is still at layer 3 I need to craft a raw layer 2 PDU.
Specifically I want to
Send a very specific DHCPDISCOVER
Receive a DHCPOFFER
and pull apart the offer while never sending a DHCPREQUEST.
Specifically I am pulling apart various options that are sent in the DHCPOFFER. I have a raw DHCPDISCOVER already crafted and the formatted struct sockaddr_ll where I fault is I can't send the damn thing. Getting the file descriptor after calling socket is okay but what now? How would I write to that file descriptor and have it transmit?
Code:
int connfd;
struct sockaddr_ll bcast;
bcast.sll_family = PF_PACKET;
...
connfd = socket(PF_PACKET,SOCK_RAW,0);
//now what
I got a problem with my CentOS server. Somebody told me OpenVPN Requires different changes inside my firewall settings. That could be the problem why openvpn wont load..I receive this error on my CentOS panel when im trying to connect into the centos openvpn (with my winxp pc):
Thu Sep 17 20:31:36 2009 TLS Error: incoming packet authentication failed from 84.xx.62.122:2622
Thu Sep 17 20:31:38 2009 Authenticate/Decrypt packet error: packet HMAC authentication failed
Thu Sep 17 20:31:38 2009 TLS Error: incoming packet authentication failed from 84.xx.62.122:2622
[code]....
I am the new user to ns-2. I would like to know is it possible to send the keys or some value as the packet data (content of the packet) in ns-2 (for wireless environment).
View 1 Replies View RelatedWas trying to understand the behavior of TCP when the server becomes unreachable . For this I am using vsftpd and the default linux ftp client to check the behavior.I was trying the following things. Was Trying to download a file from an FTP server using the FTP client as anonymous user. While the file is getting downloaded, I removed the network cable from the FTP server to understand the behavior of TCP when the server becomes unreachable.
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 ?
I checked task manager the other day and I discovered that on the network history monitor some bits and bites were transfered in a repeating pattern (like a beacon). The transfer rate (when active) is about 149b/s receiving. And about 70b/s sending. What is this?
No Internet-related program was running from my part...In an attempt to pinpoint what was causing this, I occidentally removed the tools located left and right on the time and date. I've rebooted since but still no tools. The 0/I button is also gone.
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
View 5 Replies View RelatedI am trying to redirect connection to port 8980 to execute a telnet command to a local machine
by issuing the following command :
In Server 1 :
socat TCP-LISTEN:8980,fork EXEC:/myscript,reuseaddr
My script contains
#!/bin/bash
telnet 192.168.20.12 //local Server 2
I am sending Binary data from the client to Server 2 via Server 1. So it happens that I have some characters in Hex translated to special characters in ASCII like open brackets or Commas etc.. and that closed the socket between the two machines.
I need to know how to configure automate sending sms if server reboot and shutdown? Now i just set sms notification once my server it's UP by create scripts in /etc/rc.d/rc.local while booting then from server sending sms notification. SMS - using gnokii attached mobibe phone. Server - Fedora 10
View 3 Replies View RelatedWhen I try to connect to cvs server this is the error message I get.
I also tried cvs -d server:newuser@localhost:/cvs/CVSROOT login but getting the same result
My repository is in /cvs/CVSROOT
I also tried changing /etc/xinetd.d/cvs with different options, current it looks like this:
And my /etc/xinetd.conf is
cvspserver stream tcp nowait root /cvs cvs --allow-newuser=/cvs/CVSROOT pserver
defaults
# The next two items are intended to be a quick access place to temporarily enable or disable services.
#
# enabled =
# disabled =
I would like to transfer files from my PC to my account at a sftp server, and I don't know how to do it.
My PC is running with:
User: User1
Address: 10.0.2.3
My sftp account is:
User: SFTPUser1
Address: sftp-server
I can access the sftp server with the command:
Code:
sftp SFTPUser1@sftp-server
The sftp server doesn't answer to ssh requests.
How can I transfer files to the sftp server?
Here's the system:
1 server running regular Ubuntu, 40km above the surface of the earth on a scientific balloon behind an iridium modem (RUDICS) connected to its serial port
1 server on the ground running Ubuntu server
1 intermediate server used for contacting the iridium system from the ground server
I'm not sure if all the above details are completely necessary but I included them for completeness. I would like to be able to log into the balloon server and transfer files in both directions. The procedure for connecting is to telnet to the intermediate server and then to issue some modem commands to call the balloon. The balloon server is set with getty running on the serial port connected to the modem. The way I have figured out to transfer files is to run kermit on the ground server and connect to the balloon server through the intermediate server, then run kermit on the balloon server, and set it as a file server with the server command.
However, there is some sort of timeout or something, and only a few kB of any file gets transferred before the connection is broken. After that it seems like the ground server is trying to get the file from the intermediate server (which has no useful files on it at all). The file transfer screen stays open and it keeps trying and trying to transfer, until I type ^C. I don't know if there is a way of detecting through a kermit command whether the connection is still open or if there is some sort of switch to make the transfer automatically stop once it has stalled.
I have been reading about No Kermit Server (NKS) protocol, which seems to be designed for a system like this where the connection is across a third server. Is this likely to do a better job of keeping the connection open and the file transfer going? How can it be implemented? Is there any kermit command to determine from the ground server whether the connection is actually still open? Is there any way of telling whether the connection goes all the way to the balloon server or whether it ends at the intermediate server? I actually just learned about kermit today.
On a related note, is it possible to have the balloon server running getty on the serial port but still have the port accessible for reading and writing by, say, a python script (which could use the modem to dial down to the ground when it isn't in use)? It doesn't seem to work but I'm wondering if there is a way. Is there a way to temporarily stop getty, then restart it, or is this potentially hazardous? Keep in mind there will be no way to contact it if something goes wrong since it will be 40km above the earth.
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.
View 2 Replies View RelatedI have set up a master DNS server at 192.168.50.9 and a slave DNS at 192.168.50.6. Both servers are BIND9.Machines are for testing/experimenting, hence the IP addresses. Initially, the zone transfer was blocked by the firewall on the master, as the slave uses randomly selected non-privileged ports for zone-transfer query. So, as far as I understand, there are two possible approaches:
1. Allow connections based on source, which should be
Code:
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW,ESTABLISHED -s 192.168.50.6 --sport 1024:65535 --dport 53 -j ACCEPT
(and it works for me fine)
2. Allow ESTABLISHED and RELATED connections, which would be something like
Code:
-A RH-Firewall-1-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
which was my initial idea but didn't work, but has inspired me to dig deeper into firewall configuration topics :).
Question: Does zone change notification message count for opening a dialog, or notification from master and slave zone update request are two absolutely separate actions? If the latter is true, that, of course, explains why option #2 didn't work.
This is a recent problem, and I can't pinpoint any change/upgrade that would cause this. Rsync transfer from Client to Server:
sent 11756196 bytes received 1032741 bytes 138258.78 bytes/sec
total size is 144333466390 speedup is 11285.81
Pinging back and forth from each machine is fine. No Ifconfig errors Client, but Server has RX packet errors.
eth0
Link encap:Ethernet HWaddr 00:11:25:37:ee:44
inet addr:192.168.1.101 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::211:25ff:fe37:ee44/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:41786 errors:2157 dropped:0 overruns:0 frame:2157
TX packets:34138 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:55615449 (55.6 MB) TX bytes:4737538 (4.7 MB)
What's the next step?
i am a linux fan, original i use redhat, recently, i find centOS and want to give it a try, so i install centos5.5 in vmware which is run on my IBM laptop, unfortunately, the GUI can only run in the middle of screen(a small rectangle), i can not extend it to full screen.
View 1 Replies View RelatedI have 3 Dell Precision M4400 machines. After getting updates yesterday or today, I get random network dropouts like crazy, on wired or wireless. On one machine I was able to turn off ipv6 in grub and reboot, and it works now. However on the other 2 machines, still have the same problems. All 3 are running 9.10 64 bit. Is there a way I can back out the updates so the network works again? Anyone else see this behavior after updates today?
View 2 Replies View RelatedIn my program(C++), I have a ping function call which will ping the specified IP and returns the result. The problem is, my code does not print the o/p to the terminal window after calling the ping fucntion for the first time. but, the cout statements exist before the ping function call, works fine. When i debug it using strace i found that output filedescriptor is getting closed some where through close(1), before returning from ping call. What would be the issue, can u please some one explains me what the problem is.
View 1 Replies View RelatedI am in a hub(with switches and rooters) and i want to spy what packets everyone receives! if can i do this and if i can which tools i can use?
View 6 Replies View RelatedI'm unable to reset using either the reset option in gnome shell or the command using a terminal. When I select it the shell exits and displays the graphic "exploding" and then it just sits there. Shutdown works fine; just no reset. Any ideas? I've installed from the DVD. I booted the live CD and it resets just fine so I know it's no my hardware
View 1 Replies View RelatedI am trying to simply address translate TCP packets from one destination IP to another destination IP (DNAT?) without getting the initial SYN packet. Is this possible? I do not think it is with DNAT since the conntrack needs SYN first.
I have given the command:
The problem is that the first packet that matches this rule will be the SYN-ACK and I suspect it is simply DROPPED.
I am sparing you the gory details of why I would do such a silly thing, but simply put; I need to intercept client-to-server packets through a tunnel, but allow server-to-client packets to follow through the regular network.
I have been working on this for many days w/o success and my learning curve is still steep. I can provide more details as needed.
My question is about the raw MX reply package structure. I've read the RFC and all relevant pages I could find, but I couldn't figure this one out. Say we do a google.com MX query.
The first answer (just the rdata part) will be: google.com.s9b2.psmtb.com But in the raw package, instead of the .com, you have c0 13. Then for the second answer, google.com.s9b1.psmtb.com, the raw package has, instead of psmtb.com, just c0 3a. So is the part after c0 a pointer towards another part of the message? Or what does it stand for exactly? I am puzzled by it, and don't know exactly where to ask... some of the networking people here might have a good idea.
From all the stuff that can enter an interface, how does it know when an IP packet has been *formed*? What if it's just random garbage entering there for whatever reason? Also, can Linux do other protocols besides TCP/IP? This would be the problem, as I said above.
View 2 Replies View RelatedIn application udp port listening with 3330 i am sending udp request from port 0.0.0.0:3330 to 0.0.0.0:3330 that is same port in the same machine....application works fine udp sending and receiving also fine.....for clarification ....is there any conflicts in the communication ?
View 2 Replies View RelatedI have a machine with two network cards running linux mint 8 XFCE (which is compatable with Ubuntu Intrepid Ibex). eth0 gos out onto the network propper, has a static IP address of 10.10.10.10 and serves DHCP requests for the 10.10.10.x subnet.
eth1 is pluged into a PPPoE concentrator, and has a static address of 192.168.0.1 (I would have left it alone but pppoeconf wouldn't work unless it had an address).
ppp0 is the piont to piont over ethernet conection that is corectly created when I run pon. I have both guard dog and guide dog installed but they are both disabled.
Now, the weird part: I can ping the IP number of the machine at the other end of the pppoe conection (when it changes I can still ping the new number), the local IPs (10.10.10.x), but *nothing* else not even the DNS servers passed to the machine during ppp conection which are in the same sub net as the machine I can ping.
When I try to ping or trace the route I get an error message like: reply from 10.10.10.10: desination unreachable There is nothing wrong with the network at the other end, as I can make an Identical PPPoE connection from other machines on the network if the the concentrator is pluged into the hub (a rather unsafe place for it to be) and it all just falls into place.
What seems to be happening is that the machine is treating eth0 rather than ppp0 as the internet gateway, and passing the packets round in circles.
I try to generate a server client code. What i try to do is sending video streams from eth0 and eth1 to the other server programs' eth0 and eth1. In order to do that, i decided to use SO_BINDTODEVICE. But the code is not working. Am i misunderstood the usage of SO_BINDTODEVICE.
1-Defining two ports
2-Defining two sockets
3-Assigning host ips on them
[code]....
I wrote a program for transmitting an UDP Packet. It is properly received in Fedora core 2 machine while its not received properly in Fedora 12. I tried using Wireshack packet capture software which shows the protocol as DIS. Is there any service or setting i need to do for identifying the packet as UDP.
View 2 Replies View Relatedhow to identify the icmp packets & marking. this below icmp packets marking is not working.
iptables -t mangle -A PREROUTING -p icmp -j MARK --set-mark 0x5
iptables -t mangle -A PREROUTING -p icmp -j RETURN
with the help of port no or any other how can i identify the icmp packet ?... This below two is working fine
iptables -t mangle -A PREROUTING -p tcp -j MARK --set-mark 0x2
iptables -t mangle -A PREROUTING -p tcp -j RETURN
iptables -t mangle -A PREROUTING -p udp -j MARK --set-mark 0x3
iptables -t mangle -A PREROUTING -p udp -j RETURN