3 réponses
Hello !
The notion of "port" is only associated with TCP and UDP.
IP and ICMP do not recognize this notion of port.
(ICMP is at the same level as IP.)
IP and ICMP packets do not have the same format.
See http://www.commentcamarche.net/internet/icmp.php3 for the different types of ICMP packets.
The notion of "port" is only associated with TCP and UDP.
IP and ICMP do not recognize this notion of port.
(ICMP is at the same level as IP.)
IP and ICMP packets do not have the same format.
See http://www.commentcamarche.net/internet/icmp.php3 for the different types of ICMP packets.
Actually, I have an FTP server with a Client:
to check if the connection between the two is still active, I ping
from the server to the client. My problem is when the client goes through a
router, the ping is not returned.
So I thought I could configure the router to properly return
the ping, but if there is no port, I think it won't be possible.
Any magic solution?
Thanks
to check if the connection between the two is still active, I ping
from the server to the client. My problem is when the client goes through a
router, the ping is not returned.
So I thought I could configure the router to properly return
the ping, but if there is no port, I think it won't be possible.
Any magic solution?
Thanks
Why not simply set a timeout for receiving data?
"If no data is received for x seconds, consider the connection closed."
Otherwise, I believe there is a command to send over the FTP command channel that is equivalent to a ping. (LeechFTP used it... I can't remember the command.)
It might have been NOP.
It should be found in the RFC.
"If no data is received for x seconds, consider the connection closed."
Otherwise, I believe there is a command to send over the FTP command channel that is equivalent to a ping. (LeechFTP used it... I can't remember the command.)
It might have been NOP.
It should be found in the RFC.