Networking :: Ifconfig Address With A Port Number?
Sep 24, 2010
I'm trying to grok a problem I'm having with an embedded machine. I'm pretty sure I can track down the larger problem, but I came across a usage of ifconfig that I don't understand, and I'm pretty sure this is the command that is failing.
The command is: ifconfig eth0 192.168.78.20:9134
I understand how ifconfig works. What I don't understand is the :9134. I can't see anything in the docs about what this means. I know in most contexts it's a port number, but what does it do when bringing up a network interface? Does it limit it to only using port 9134?
I recently installed a new CPU and motherboard in my Media Server, but the ethernet port isn't showing up under ifconfig. Is there any way to install additional drivers? EDIT: The model is Realtek RTL8111/8160B.
Currently my OS is Ubuntu 9.04 Jaunty Jackalope Desktop OS and my web server is Apache2. I have a public address 60.x.y.z and my pc local address is 10.x.y.z. I have a web app in my Apache2 which currently run in localhost(10.x.y.z).
I would like to enable the web app so that it could be browse from outside. I know there maybe some port forwarding process and some commands involved in order to do that. But I have no idea on the steps to do that.
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.
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..
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 18.104.22.168/23451 and 22.214.171.124/23452 Receiving on 126.96.36.199/23452 and 188.8.131.52/23451
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 [184.108.40.206/23452] take its datagrams from emitter [220.127.116.11/23452] and vice-versa!
I have 3 gateways in my office. I want to redirect all web traffic (port 80 and 443) through one gateway and ssh connections through other one. All machines have single network interface. For this what I did is created an ip alias et0:1 and assigned ip to it. Then wrote an ip route rule to route packets from eth0:1's ip to other gateway. All other traffic will go through default gateway. But here I am not sure how I can make web browser to use eth0:1's ip. It's using eth0 's ip. I wrote a ip table rule to change source ip of http packets to et0:1's ip. But rule is on POSTROUTING chain. So I think it's happening after routing.
I enabled D-Link (DSL-502T) router web management (I am aware of security implication). I was able remotely to login to the router (by typing http://23.45.xx.6y) before changing the default number 80. Then I changed the port number from the default value 80 to 21908 (https option is not available) for better security, and when I tried to login to the router by typing this :
Yes I am aware that if I am physically near to the router then I can check that , but this is not the case with me. How can I make sure that I had changed port number form 80 to 21908? Does NMAP do a trick to reveal which port is used for web management ? or are there other better options?
I'm not that great with mailservers, and just been thrown a curveball with a MS Exchange environment for which there is apparently no solution... yeah, right. But is there a workaround?
The problem is that the site mail (SMTP) needs to be sent via port 26 instead of the commonly used 25. Port 25 is mapped to a mailfilter, which apparently causes havoc with some of the mail, and the techs that have been on site trying to coax the Exchange server to co-operate have said that the only way would be to get rid of the filter.
The problem is that there are number of apps that are unable to have the outgoing port changed and so keep sending mail out on port 25.
I look after the Unix/Linux side of things at work, and I was wondering if there was an easy way to set up a Ubuntu box to receive mail on port 25 and just forward it to the MS box on port 26? So, in other words (and I hope this makes sense): monitor port 25, and forward whatever comes in on port 25 to the server on port 26. Simple portforwarding, or is it? What steps do I need to take?
I would like to create several aliases to eth0, but have the addresses assigned by DHCP instead of being set to static IP's. Is this even possible? All the examples I've seen assign a static IP using the command: ifconfig eth0:0 192.168.1.11 up
Is it possible to forward a connection to a port to a completely unrelated external address? For example, I want to redirect ssh traffic to a.b.c.d to w.x.y.z. If w.x.y.z were an internal address and the machine was the router, this would just be plain old NAT port forwarding. But what if w.x.y.z is not an internal address? The reason I want to do this is I want to reassign a domain name example.com from ip address A to B, while allowing users to still ssh into A by using the [URL] domain name. Is this unreasonable? (I am guessing it is unreasonable, since the A wouldn't have it's gateway set to B, as is the case if A were in B's NAT'd internal network.)
it was working but after i installed updates and rebooted it could not get a ip address seems like strange timing it still registers under ifconfig it is not even working on the live usb anyway i can test to be sure it is the chip?
where are the interface configurations (set by ifconfig, not the static ones) stored? I'm asking because I'm trying to understand, more broadly, the order of IP address lookup. If I ping the local machine (localhost, or one of the interfaces) no messages get sent out (at least according to wireshark), so some local lookup must be taking place.
I want to pass ip address,port address and some parameters from command line using python script.The ip address and port address for establishing socket connection and remaining parameters to execute different connection.
My college providers shifted to a different setting.. I'm not sure what needs to be done. On windows, under the connections tab you need to change the proxy settings and put in the IP address and enter the port to 3000. Questions:
1. where lies the linux (ubuntu 10.04) variant to execute the operation.
2. What can be the major obligations of such a change?
I am sure its siimple enough, but I can't get my net to work properly. The connection provided to the internet is through wireless routers.
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
im using CentOS 5.2 and cant change my default ssh port number. I have edited /etc/ssh/sshd_config to this
#$OpenBSD: ssh_config,v 1.21 2005/12/06 22:38:27 reyk Exp $ # This is the ssh client system-wide configuration file. See # ssh_config(5) for more information. This file provides defaults for # users, and the values can be changed in per-user configuration files
I have then restarted ssh by typing (as root) "sbin/service sshd restart" and it restarts fine but still is on 22 and not 222.
i have installed CentOS along with ISPConfig. For some reason apache will not run it says there are no listening sockets avaliable. I have done a netstat and also tried nmap to see if any other service was using port 80 but it doesnt show anything. I also tried changing the port number to something like 81 still no go. On bootup of CentOS it shows the error and a message saying unable to open logs.
Is it possible to setup SSH Daemon to listen on multiple ports and only accept specific groups to a given port? In the past I've created a second SSH Daemon by copying the config file and /etc/init.d/ daemon then configuring each port separately / rules however if I was able to maintain just the one Daemon that would be optimal. Is this possible?
I would like to change port number for a specific folder name on linux server like domain.com/folder_name:yyyy so people can access that folder with pre defined port number. is there a way that I can do that?
I have system with debian linux installed. i got to know that debian doesent have IPTABLES firewall installed in built. i found the shoerwall firewall installed on system. now i wanted to open port no.7 for application comunication purpose please let me know if any one knows.also one more thing.. if i type command iptables --list i can see list of rules installed on ssytem....confuse which firewall application installed on the system.
we have centos and a win2k8 server. Our pos system is on the centos server. I created a HOST (A) record on win2k8. so users don't have to remember the ip address of the centos server.so i created a friendly name like URL... and the POS web page will be loaded.but my questions is it possible to configure the centos to automatically append the port number if the user type URL... will be auto added at the end of it.