Networking :: Understanding Netstat TCP Port
Aug 1, 2011I have an application that uses port 8080 all the time. One time, for some reason, it was taken by I didn't know what.
View 2 RepliesI have an application that uses port 8080 all the time. One time, for some reason, it was taken by I didn't know what.
View 2 Replieswith netstat i found a port with idle state, i google the meaning of IDLE:Idle, opened but not bound.What do you mean by bound?
View 2 Replies View RelatedI need the port 27015 to be open. I've opened it in iptables :
Quote:
iptables -A INPUT -p tcp -i eth0 --dport 27015 -j
But when i try :
Quote:
netstat -nan
The port 27015 do not appear as "LISTEN".
Netstat has always confused me. I ype netstat -pl and get this:
Code:
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 localhost:ipp *:* LISTEN 1476/cupsd
tcp 0 0 localhost:postgresql *:* LISTEN 13816/postgres
tcp 0 0 *:44223 *:* LISTEN 1288/sshd
tcp6 0 0 localhost:ipp [::]:* LISTEN 1476/cupsd
tcp6 0 0 localhost:postgresql [::]:* LISTEN 13816/postgres
tcp6 0 0 [::]:44223 [::]:* LISTEN 1288/sshd
udp 0 0 *:bootpc *:* 1267/dhclient
I assume that *:* means that any foreign host can connect from any port, but then what does [::]:* mean? and localhost:ipp... what port is ipp? Shouldn't ports be numeric?
had some problems with setting up Linux on my virtual machine as I cannot connect with putty (connection gets refused) to it but now I guess I figured my problem out, just not the way how to solve it .If I do netstat -nap | grep :22 I get the following output:[[ see attachment ]]
Shouldn`t there be some kind of LAN IP instead of 0.0.0.0?Does anyone have a possible solution for that? Checked iptables and such, they are not causing it.
I'm trying to open port 8080 on my application server. I've included it in my iptables; however I still cannot access through ssh nor putty and it doesn't show up when I netstat either.Here is my iptables-config:
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -i eth0 -s xxx.xx.x.0/24 -j ACCEPT
[code].....
I have question regarding netstat? When performing a "netstat -s" I receive the following information regarding dropped packets under IP:
IP:
93978695 total packets received
0 forwarded
0 incoming packets discarded
79472157 incoming packets delivered
65235033 requests sent out
29527 outgoing packets dropped
However if I run a "netstat -i" I have no dropped packets whatsoever: (apologies for the table format):
Kernel Interface table
Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
bond0 1500 0 34326528 0 0 0 72755307 0 0 0 BMmRU
bond0:1 1500 0 - no statistics available - BMmRU
bond1 1500 0 28605491 0 0 0 20948952 0 0 0 BMmRU
eth0 1500 0 34199550 0 0 0 72755278 0 0 0 BMsRU
eth1 1500 0 126978 0 0 0 29 0 0 0 BMsRU
eth2 1500 0 97911 0 0 0 1 0 0 0 BMsRU
eth3 1500 0 28507580 0 0 0 20948951 0 0 0 BMsRU
lo 16436 0 34094225 0 0 0 34094225 0 0 0 LRU
I want to do a simple port redirect, i.e. whatever comes trough whatever interface on port AAAA will get redirected to port BBBBI thought that iptables -t nat -I PREROUTING --source 0/0 --destination 0/0 -p tcp --dport AAAA -j REDIRECT --to-ports BBBBhowever it doesn't work, e.g. nc -v -w2 -z localhost AAAA gives:
nc: connect to localhost port AAAA (tcp) failed: Connection refused
while
nc -v -w2 -z localhost BBBB
[code]....
While running some live tests last week I saw an odd situation where netstat appeared to be displaying the wrong PID and process name for TCP connections. I'm trying to figure out if this is just a strange netstat bug or if it could indicate something odd is happening with our software.
We have a main program which establishes a number of connections, including connecting to a JMS server and listening/accepting a TCP connection. The main program also creates a child process which it uses to communicate with another server. On at least three occasions we saw a situation we saw netstat reporting all the expected TCP connections (correct ip/port for both source and destination), however the child process, instead of the main, was listed for the PID. The main process was still running but netstat no longer reported any TCP connections established by the main program. The main program continued to function correctly, the JMS communication continued to work and we believe the other TCP connection was functioning correctly despite the program supposedly not having any TCP connections.
I'm wondering if this could simply be a bug and/or obscure functionality of netstat that I don't understand which would cause netstat to report the child process as 'owning' the parents TCP connections. I don't know how this would happen or why the parent would continue functioning despite the problem otherwise.
While issuing the command netstat -M it shows netstat: no support for `ip_masquerade' on this system. But this system is used as a gateway and iptable rules are set for ip forwarding. Also internet is getting another machine through this machine. What about the message?
View 3 Replies View RelatedWhen the centos is running a vpn server, there 's a client connecting. The connection can't be seen by netstat -tunp
View 4 Replies View RelatedI just found something "strange" by using netstat
tcp 0 0 myhost.deprecated:53719 amaretti.chimfar.:54406 ESTABLISHED
How can I check what is the program that is responsible for this line?
I've been experiencing some home web-server slowdown issues lately, and I wanted to see if it's a problem with the server itself. I'm not sure if this might be the problem, but upon checking netstat -tn, I see over 15 instances of the following:
[Code]...
where 192.168.2.9 is the server's local address, the local address port varies, and the foreign address is the server's web address. If anyone knows what might be causing this and/or how to fix i
I have a small office network (about 30 machine) with linux gateway (6Mbps internet bandwidth). Every user get only 500Kbps bandwidth, and they use the internet very poor. The internet getting slow lately, and I noticed that there are huge amount of small packets (78 byte, 48 byte) coming to linux machines. My question is: How can I solve which machine(s) sending those small packets? Do you have any ideas with netstat command?
View 1 Replies View RelatedUsing netstat I can get a lot of network related information which is pretty useful at times. But when I use for example 'netstat -s' it gives me a lot of counts for bits transferred or data packets transferred etc. Now one thing I am not sure of is that for how long those counts will keep rolling and when will they get reset (when I restart the machine?, when I restart the network services? Or if there is some kinda threshold set on it?) How exactly netstat counts those things (I mean what is the source of those counts for netstat).
View 2 Replies View RelatedWe are running a combination of Apache-2 with mod_jk connecting to tomcat workers running on separate hardware.Strange: "netstat -tn" on the Apache server outputs identical combinations of source address, source port, destination address and destination port.
Has anybody else experienced this phenomenon? (I googled and searched LQ but couldn't find anybody else reporting this)Is netstat broken, or is there another explanation?
How to reset (clear) statistics for the "netstat -s"?
View 1 Replies View RelatedWhen I use the following command:
ssh user@ssh_server -L 5500:localhost:5500 -p 22
everything works fine. I can log in, and local port forwarding is done. Otherwise when I use the command:
ssh user@ssh_server -R 5500:localhost:5500 -p 22
I get an error "remote port forwarding failed for listen port 5500". However when I try remote port forwarding in WinXP by use of putty there is no problem...
I'm trying to use iptables in order to forward all the incoming packets for port 5555 to port 5556 on the same server (192.168.2.101).
I wrote the following commands:
iptables -A PREROUTING -t nat -i any -p tcp --dport 5555 -j DNAT --to 192.168.2.101:5556
iptables -A FORWARD -p tcp -m state --state NEW -d 192.168.2.101 --dport 5556 -j ACCEPT
I'm using a Debian servers, as router/firwall.. I've two ethernet interfaces into the server, one for wan and one for lan. The i use SNAT so my LAN clients can access the internet throgh the debian router. That is working... Now i want to be able to access servers on the LAN site from the WAN site, and i wanna use port address translation (PAT). I have a FTP server running on a lan server, so i'm trying to portward port 21.
iptables -t nat -A PREROUTING -p tcp -i eth1 -d (WANIP) --dport 21 -j DNAT --to 192.168.1.2:21
When people try to access my FTP from the WAN site, they are redirected to the local FTP server, and they are promted for crendentials, but when the credentials are typed, and the local ftp server should answer the wan request, the connections dies.
The wan clients are being promted for credentials, so they are redirected to the local lan server, but after that the connections dies, so i think there is some kind of nat problem, when the local lan server is trying to respond to the wan request..
Here i my iptables script:
#flush table
iptables -F
#input regler
[code]....
I make an application on GNU/Linux which listening on a MULTICAST stream, so I open my unconnected socket, bind it on a MULTICAST address and a port, join the multicast group with the "setsockopt (IP_ADD_MEMBERSHIP)", then I receive datagram on my socket.
Now I've two different instances of the same application that run with their own MULTICAST address and port. And what I found strange is that, after a misconfiguration, I switch the ports, for example:
Emitting on 225.0.0.1/23451 and 225.0.0.2/23452
Receiving on 225.0.0.1/23452 and 225.0.0.2/23451
And my receiving part doesn't care about the MULTICAST address, it looks like the socket is listening on the port number only! I mean that the receiver [225.0.0.1/23452] take its datagrams from emitter [225.0.0.2/23452] and vice-versa!
I want to set my ip as static and port forward it through a specific port can anyone help me with this im using ubuntu 10 with 64 bit OS
View 1 Replies View RelatedHow can i redirect data received on a port to another port located in a different machine? Can i do this using IPTABLES ?
View 4 Replies View RelatedI have a mail server on which I would like to block port 25 on my eth0 for everyone except our external spam filter. the problem is that I want our users to be able to connect via port 10025 which is forwarded to port 25, which then is blocked...
View 2 Replies View RelatedI had to add them to my firewall script when I installed openvpn on my dd-wrt router:
iptables -I FORWARD -i br0 -o tun0 -j ACCEPT
iptables -I FORWARD -i tun0 -o br0 -j ACCEPT
iptables -I INPUT -i tun0 -j REJECT
iptables -t nat -A POSTROUTING -o tun0 -j MASQUERADE
what should I add/change to set up port forwarding of port 1000 to ip 192.168.1.200. also how to get the answer sent by 192.168.1.200 follow the same route used by the data received through port forwarding.
i have an embbeded hardware that uses bootp for booting from a Network Managemnt Host (NMH)on the same ethernet. The embedded hardware has both kind of ports i.e ethernet as well as E1/T1. I would like ask, what do i require to establish a communication-link between the embedded hardware and the NMH throuh E1/T1 ports of embedded hardware, so as to make it boot through from E1/T1. Further, NMH possesses only ethernet port. Just to refine my questions i'd like to know what additions do i need to do on my NMH , like may be i have to put an E1/T1 port or is it possible that the E1/T1 port can be directly connected to an ethernet port on the other host.
pardon me if i am not making absolute sense here as my knowledge is limited on Layer 1 and layer 2.
how to access networking port and run scripts on that port so as to gain access of remote machine.is that possible through command prompt or through software.
i kno ip address of my frnd who is chattin with me .okay.i want to run an application on his computer .i came to kno tht we can run script o through port
I installed ZTE MF 626 modem in my F10 with kernel 2.6.27.12-170, i run usb_modeswitch and so far things happened normally. Watching through /var/log/messages it says that F10 detects two port device for this modem: ttyUSB1 and ttyUSB2, and in the sequence it disable port ttyUSB1 BUT Network Manager still set this port.I mean, when i connect via wvdial appointing to ttyUSB2 i get connection, but Network Manager fails to do it appointing to ttyUSB1. How to change device port in Network Manager?
View 1 Replies View RelatedI am running lmgrd on CentOS5, but it returns Failed to open the TCP port number in the license. The port is 27000, how can I open that port?
View 5 Replies View RelatedI am developing a node application and there is an option to set the process title (process name). This only sets it in some tools (like ps and top), but not in htop or netstat.
I found this article that explained how most applications do it, but it doesn't change in netstat.
That lead me to wonder where those programs are getting the process name. Would they be getting it from /proc/##/cmdline? (## being the PID of the process)
I figure messing with things in /proc is a bad idea (and probably not possible), so if this is where those programs are getting it, is there a way to change it?