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> From: bss@iguanasuicide.net > To: debian-user@lists.debian.org > Subject: Re: netstat ? > Date: Tue, 23 Feb 2010 23:59:41 -0600 > > In <[🔎] SNT125-W503AD2F570F2C86CE7A4AFDB410@phx.gbl>, Hadi Motamedi wrote: > >My Debian server is at @172.16.128.1 and the remote network element is at > > @172.16.4.1 , but the 'netstat' does not show the ip address and the > > assigned port from my Debian . It just shows many dedicated ports , > > assigned with '0.0.0.0:xx' format . Can you please let me know how can I > > distinguish the dedicated port to that remote network element ? > > There's not one. That's not the way TCP/IP or UDP/IP servers work. All the > client connections use the same server IP address and port. The TCP/IP or > UDP/IP stack separates them into different connections based on the source > address. Netstat shows sockets, not connections. > > In pictures (ASCII art, view in a fixed-width font): > > src = "" src = "">> +----------+ dst = x.x.x.x:dx +---------+ dst = x.x.x.x:dx +----------+ > | Client 1 |----------------->| Server |<-----------------| Client 2 | > | y.y.y.y | | x.x.x.x | | z.z.z.z | > | port ry |<-----------------| port dx |----------------->| port rz | > +----------+ src = "" +---------+ src = "" +----------+ > dst = y.y.y.y:ry dst = z.z.z.z:rz > > There are a number of tools that can "look in" to the TCP/IP or UDP/IP stack > and give you per-connection metrics. I think iptraf is one of them; tcpdump > can also be used. Someone with more network monitoring experience will have > to mention any others. > -- > Boyd Stephen Smith Jr. ,= ,-_-. =. > bss@iguanasuicide.net ((_/)o o(\_)) > ICQ: 514984 YM/AIM: DaTwinkDaddy `-'(. .)`-' > http://iguanas uicide.net/ \_/ Thank you for your reply . Sorry , you mean the tcpdump can be used to monitor the exchanged packets toward an spesific ip address ? I thought that it can just monitor all of the packets on my eth0 and then I need to find the dedicated port to try to filter with . If it can do that , please provide me with an example on how to use it to monitor for an specific ip address ? Hotmail: Powerful Free email with security by Microsoft. Get it now. |