I have a network application environment of 7 applications communicating with eachother through UDP and TCP. All of them using either the machine's local network IP or 127.0.0.1 (localhost) to listen on ports or connecting to eachother.
All these applications are running on a single test machine.
I want to analyze precisely how each application communicate with the others so I tried Wireshark and Netmon. However both Wireshark and Netmon don't show me any of the packets sent or received by any of these applications.
What can I do to analyze this environment? Does Wireshark or Netmon able to analyze that? Is there a problem tracking packets using same source and destination IP?
what interface did you select in Wireshark for capturing traffic?
For your case, I think you should select "Adapter for loopback traffic" in Wireshark.
It will capture loopback communication for your locally hosted application.
Related
I'm trying to run a socket connection from my iOS app to a bespoke server.
The iOS communicates via UDP to the server on port 12345. The request needs to come from socket 54321 on the device.
How do I open up a socket connection on iOS that communicates to a server on one port but listens via a different port.
I have followed the example on:
https://www.raywenderlich.com/3932/networking-tutorial-for-ios-how-to-create-a-socket-based-iphone-app-and-server
But this does not cover the local port
I have also looked at the documentation on https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/NetworkingTopics/Articles/UsingSocketsandSocketStreams.html but I am finding it unclear due to my limited knowledge of socket connections.
I am currently attempting to use https://github.com/robbiehanson/CocoaAsyncSocket/wiki/Reference_GCDAsyncSocket
But I don't seem to be able to control the local port.
Thanks in advance
Normally you don't care about the sending socket, but when you create your AsyncUDPSocket you can use bindToPort: to set its port. Then use sendData:toHost:port:timeout:tag: to send the data
This is related to this question: How to Capture Remote System network traffic?
I would like to be able to export live traffic captured on a Linux server and to view that in real time on my Windows machine.
Please do not suggest SPAN or RSPAN because it does not apply to my needs. This is about internal traffic (VM traffic) that tshark can see without any problems, I would just like to watch the traffic on my desk (Windows machine) with Wireshark
You should use the tool rpcapd in the machine (A) that you want to capture the traffic:
rpcapd -n -p <port>
With -n is launched without authentication
Finally, in the other machine (B) go to Wireshark > Capture > Interfaces > Options > Manage Interfaces > Remote Interfaces
And you should see the traffic of Machine (A)
I think that the only viable way to do it is to use Wireshark with X11 remote desktop. VNC may also work but you don't really use the Windows System resources to display the results, everything is still processed on the Linux server.
Hi I am new to BIOS and UEFI firmware. I am using PXE to download boot images for UEFI and BIOS.
I found that when I do network boot using BIOS, it broadcast UDP packets and my PXE server can process it.
But with same configuration if I do network boot using UEFI, target system does not broadcast UDP packets.
I have created a target system (bare metal system) on VMware ESX 5.5.
I am using wireshark to debug. I can see that In case of EFI based boot target does not get the ip address. Even though my DHCP server broadcast DHCPOFFER packets, target continuously sends the DHCPDISCOVER packets. I mean at some point in time target has to send DHCPREQUEST packet. But same thing works fine if I boot through BIOS.
Above problem get solved If I add bootfile name and nextaddress in dhcp.conf (DHCP Server is in Linux). But as per my requirement I can not hard code the nextAddress and bootfile name, it will be added on fly in PXE server.
Edit 2: So in my case I am adding all the required parameters at PXE side like next server address, boot file name etc.
But if I do that I am not getting reply (DHCPREQUEST) back from client (UEFI based client) . But if configure same parameter at DHCP server it works well.
In case of BIOS in same environment, I have configured all parameters in PXE server and I am getting reply back (DHCPREQUEST) from client.
Just a pointer do we need to enable something at UEFI client to listen PXE parameters (Options). In my case I have made "EFI NETWORK" as primary boot.
Please help me on this. Thanks.
in both cases when the target starts a network boot it will initially broadcast the DHCP DISCOVERY packets.
If you do not see them when net booting UEFI based targets then you are probably not really netbooting or you have some firewall issue.
Edit 1.
You have a DHCP and a PXE server both providing booting info?
that's not good. You can either have:
DHCP server offering PXE parameters
Regular DHCP server plus a proxyDHCP only offering PXE parameters.
read what a proxy server does here
If efi fails to get the IP it is because is not receiving a an IP "plus" the PXE parameters.
Can someone explain why using a port is necessary when running things locally?
I assume the reason is because the same software could be run remotely and in that case specifying a port would be necessary.
When a database or server is running locally, do requests from a locally running web browser really "go through the port" specified?
Good question. In fact, there are local-only communication protocols, such as pipes and UNIX domain sockets that do not actually require port numbers to operate. This is because they refer to files or other identifiers that are only valid on the computer itself.
However, most servers are designed for TCP/IP connections. TCP/IP itself specifies a port number in the protocol. It is normally intended for remote use, but when a server that is used to TCP/IP runs "on local host", it must supply a port number to satisfy the TCP protocol.
Port numbers also enable multiple servers to coexist on a single computer, all running on different ports. For a protocol without port numbers, this is achieved by using different identifiers (e.g. a filesystem file) for each server.
Some servers can operate on both TCP/IP and local sockets. For example, MySQL can accept connections both through the usual TCP port, and also through a local socket (mysql.sock). Connecting through the local socket is reserved for local users only, and may be faster on some systems.
Sometimes You may have some other software installed in your computer that may use the same port. For instance Apache and IIS: imagine you set port 8080 to IIS as default, what about if you had previously installed Apache set port 8080 ?
Another example will be if you installed Mysql Workbench and days later install XAMPP you may have trouble with the ports if you don't change one instance's port different from 3306
This is why it is necessary to specify ports even though is locally.
I made a C# program with a client and a server that comunicates fine between them. Information is received by the server and stored in a MySQL Database with no problems. However I wanted to use wireshark to monitor how safe/encrypted was the information and couldn't find the communication using wireshark. My program uses sockets to connect the server and client, on my test the server and client are running at adress 127.0.0.1 or local IP machine (something like 192.168.13.191), server listens/connects using port 3608 and client a much higher random port, and all the filters I used on wireshark return nothing.
So far I tried:
ip.addr == 127.0.0.1 (show only packages whose origin or destination are 127.0.0.1)
ip.addr == 192.168.13.191 (same as above)
tcp.port == 3608 (show only packages whose origin or destination is this port)
tcp.port == client_port (same as above)
tcp contains 01:00:00:3B (only packages with a few of the bytes I'm sending)
My idea was to find at least one message from the client to server and use the "Follow TCP stream" option from wireshark, but all these filters return a black screen when used individually. I have no idea why, because when I run netstat -a on a windows command I can see the program have a established connection and is also listening for new connections on port 3608. Anyone have any idea what is going on or what filter should I use? Operational system somehow is "redirecting" traffic from port 3608 to another?
Thanks!
Wireshark doesn't pick up loopback packets. You'll have to install the client or server on another machine and then try again.
EDIT: After doing some reading I've discovered that this really doesn't have anything to do with Wireshark but with the way WinPcap works. In any case, running the client or server on another machine will solve the problem.