Does a Windows loopback adapter supports ACD and duplicate IPs. Say we have a code that supports full TCP stack and we bridge the program to loopback using PCAP.
If in case I set both the address same - is it the right way to test ACD? Do we need always wired devices to test ACD?
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I'm looking to write a simple Windows driver to enable running TCP/IP over a proprietary RF module. The module already provides Ethernet-style data packets with source/destination MAC, so I just need to layer IP packets (generated by the regular Microsoft IPv4 subsystem), set the MTU appropriately so they will be the right size, and then call the module's serial API. I'll need to be able to handle transmit statuses and implement an ARP protocol as well. I want the driver to expose a new interface similar to a wifi or ethernet card in Network Connections and use the normal Windows IP stack.
The module is UART and might be connected via FTDI chip, RS-232 converter, or native UART on an IoT Core board, so it will just be talking to a generic serial port. I am fine with only running on Windows 10, but I'm still not sure what to use. Can I use the UWP VPN provider? Do I need to write an NDIS miniport driver, or an interface provider? Also, how will I handle the driver needing complete control over the serial port at all times? I can't write a serial driver as it might be connected via many different types of serial ports.
I am a developer of WinPcap, a famous packet capturing and sending software under Windows. I have ported WinPcap to NDIS 6 Light-Weight Filter technique, but it still doesn't support loopback packets (such as packets sent to and received from 127.0.0.1) capturing because of Windows' nature: The loopback packets are handled directly in TCP/IP stack and don't go down to NDIS layer.
Someone told me that Windows Filtering Platform can see the loopback traffic, so I have done some research about it. I have several questions about this.
1) What are actually loopback packets? I mean the packets NDIS can't see? Like when I ping 127.0.0.1, these ICMP packets are definitely loopback ones. When I ping an address that a local network adapter has bound to (like 192.168.0.24), it is also loopback I think. Are these all conditions? If yes, then I can filter out which packets are loopback ones based on whether their local IPs are 127.0.0.1 or local adapter IPs (like 192.168.0.24).
2) I learnt that WFP has many layers, I think my requirement should use the "IP Packet (Network Layer)", I wonder that can WFP Network Layer captures all loopback packets inbound and outbound?
3) I don't know if the loopback packets captured by WFP will have an Ethernet header? If not, then I think I should manually add Ethernet header to the packet prefix before sending them to user mode, as WinPcap is an ethernet-level packet capture software and many software using WinPcap (like Wireshark) will by default parse the packets from Ethernet layer. However, I think I will let the whole Ethernet header to be all-0, as there's actually no Ethernet header in fact.
Thanks and appreciated for your help!
Under Windows XP, SP 3, is it possible to forward loopback packets to a physical network card?
This is one of many attempts I'm making at being able to sniff loopback traffic. The best-looking lead I have so far is to use RawCap, but it's just not grabbing the packets for some unknown reason (I have another post on this topic).
Also, I'll note that Windows Loopback Adapter (WLA) is not a solution for me. The traffic I'm trying to catch is on 127.0.0.1. WLA requires an address other than 127.0.0.1 be used.
Thanks,
Dave
I think you can set any IP that you want to microsoft loopback adapter.
You can use Wireshark / winpcap and monitor the loopback adapter itself.
Is there a way to find out the IP address of a device that is directly connected to a specific ethernet interface? I.e. given one host, one wired ethernet connection and one second host connected to this wired connection, which layer or protocol below IP could be used to find this out.
I would also be comfortable with a Windows-only solution using some Windows-API function or callback.
(I know that the real way to do this would probably via DHCP, but this is about discovering a legacy device.)
Mmh ... there are many ways.
I answer another network discovery question, and I write a little getting started.
Some tcpip stacks reply to icmp broadcasts.
So you can try a PING to your network broadcast address.
For example, you have ip 192.168.1.1 and subnet 255.255.255.0
ping 192.168.1.255
stop the ping after 5 seconds
watch the devices replies : arp -a
Note : on step 3. you get the lists of the MAC-to-IP cached entries, so there are also the hosts in your subnet you exchange data to in the last minutes, even if they don't reply to icmp_get.
Note (2) : now I am on linux. I am not sure, but it can be windows doesn't reply to icm_get via broadcast.
Is it the only one device attached to your pc ?
Is it a router or another simple pc ?
To use DHCP, you'd have to run a DHCP server on the primary and a client on the secondary; the primary could then query the server to find out what address it handed out. Probably overkill.
I can't help you with Windows directly. On Unix, the "arp" command will tell you what IP addresses are known to be attached to the local ethernet segment. Windows will have this same information (since it's a core part of the IP/Ethernet interface) but I don't know how you get at it.
Of course, the networking stack will only know about the other host if it has previously seen traffic from it. You may have to first send a broadcast packet on the interface to elicit some sort of response and thus populate the local ARP table.
Windows 7 has the arp command within it.
arp -a should show you the static and dynamic type interfaces connected to your system.
Your Best Approach is to install Wireshark, reboot the device wait for the TCP/UDP stream , broadcasts will announce the IP address for both Ethernet ports
This is especially useful when the device connected does not have DHCP Client enabled, then you can go from there.
You can also get information from directly connected networking devices, such as network switches with LDWin, a portable and free Windows program published on github:
http://www.sysadmit.com/2016/11/windows-como-saber-la-ip-del-switch-al-que-estoy-conectado.html
LDWin supports the following methods of link discovery: CDP (Cisco Discovery Protocol) and LLDP (Link Layer Discovery Protocol).
You can obtain the model, management IP, VLAN identifier, Port identifier, firmware version, etc.
I'm writing a network application in ruby which should use UDP multicasting.
My problem is that I want to run multiple instances for testing purposes on localhost, but multicasting only works if I bind the socket to the real network interface.
Is there some way to enable multicasting for the loopback interface, so that all the 127.0.0.x get the message I send?
Currently I enable multicasting with:
ip = IPAddr.new('234.56.78.9').hton + IPAddr.new('0.0.0.0').hton
socket.setsockopt(Socket::IPPROTO_IP, Socket::IP_ADD_MEMBERSHIP,ip)
#socket.bind '127.0.0.1',1234 ##does not receive multicast :(
socket.bind '0.0.0.0',1234
Also, I noticed that if I e.g. bind the socket to 127.0.0.4 and send a message, in the packet the source ip is 127.0.0.1 anyway... is there a way to set the source IP so it shows the same IP I bound the socket to?
Solaris allows you to use multicast on the loopback device. For other operating systems you can enable IP_MULTICAST_LOOP on the sender (Unix) or the receiver (Windows) for similar effect.