with Scapy I can sniff packets and filter by destination.
sniff(filter="dst <ip addr>")
How do I use Scapy to only forward packets that are being sent to that specific ip address?
You can use the prn argument for sniff like this
sniff(filter="your ip address", prn=process_packet)
Where process_packet is a method that do what you need, like this
def process_packet(pkt):
here you do what you need with the sniffed packet
Sniff function will apply process_packet to every packet that is sniffed.
Hope this is what you asked.
Related
I was studying about packets and networking and i think that the packet have a header which contain source address and destination ...
but since the destination is the IP of the router so after the packet reach the router how does the router know which device it should forward the packet like 192.168.1.2? or 192.168.1.3?
or does the packet contain the internal IP too
thanks for any answers .
Are datagrams a protocol or not?
Is "Ping" (protocol ICMP) used in an IP DATAGRAM? Or is it using other protocols, such as TCP or UDP?
How do you know the message "Reply" the way back?
Why the Tel number stays the same?
https://en.wikipedia.org/wiki/IPv4#Protocol
Datagrams are basically the packets that go back an forth over the network at IP level. Each of these packets can specify a protocol. You can have TCP, UDP, ICMP, etc. (see https://en.wikipedia.org/wiki/List_of_IP_protocol_numbers)
So to answer your question, yes the protocol for datagrams is basically IP.
You can have higher level protocols that run over IP such the one above.
See https://en.wikipedia.org/wiki/Internet_protocol_suite
Ping uses the ICMP protocol.
Are datagrams a protocol or no?
'Datagram' is the name of the unit of transmission in the UDP protocol.
Is "Ping" ( protocol ICMP ) used in a IP DATAGRAM?
The question doesn't make sense. It would make more sense to say that the ICMP protocol is transmitted via IP packets.
Or is it using other protocols, such as TCP or UDP ?
ICMP is a protocol: you said so yourself; and it is layered over the IP protocol.
Can anyone give me an example of a wireshark filter for capturing incoming tcp/ip packets, and another for capturing incoming packets on a specific port?
Here you can find various examples.
For incoming ip packets: ip.src==1.2.3.4 or for packets on specific port tcp.port eq 8080 and you can combine queries with logical operators
I connected two machines via a network cable. I need to get an ARP request data via Wireshark. When I pinged the IP of the other machine, I get the ARP request on Wireshark. But, it is not broadcasting a message. It targets pinged IP address directly. I think a LAN with only two machines does not need to do a broadcast. Am I right? Can any one explain this to me?
Always in ARP packet, MAC address will be broadcast not IP. As it is used to learn MAC address of other host whose IP address is known, ARP packet needs to have valid IP address rather than broadcast IP. You can check ARP packet example at below path:
http://wiki.wireshark.org/AddressResolutionProtocol
Hope this clears your doubt.
As UDP is a connectionless protocol, once the forwarder gets a packet and sends it to a target ip, and the target ip responds with data, how can the forwarder know what ip to send the packet to?
If you are talking about a standard gateway, it knows where to send it because the packet has a destination IP address and port.
If you are talking about NAT, then the router must remember what it has recently sent out and accept corresponding incoming packets. The router maintains a session internally, which will stay alive for some configured period.