Managing and using network connectivity on a unix system

learn more… | top users | synonyms (1)

1
vote
2answers
42 views

How to know URL being observed directly in a server

I host many websites using cpanel. I want to know URL being accessed at real time. It seems that many old domains still point to my host and they seem to take a chunk of CPU
2
votes
0answers
60 views

Want to assign dedicated default gateway on Two NIC card on linux server

We have one server having two nic cards. Here we configured two separate networks on both nics and having different gateway. However our one sub-net is able to communicate to outside network second ...
0
votes
0answers
38 views

Server load is very high with unusual iftop result

Sometimes my server load is insanely high. Things like 120 or something. I checked what's wrong. What I see can be seen in this question: How do I interpret this IFTOP result Basically when I run ...
4
votes
1answer
89 views

What does this netcat output mean?

I want to telnet into my locally running VM which has a dictd service running on port 2628, when I issue my nc -v command though I get the following: $ nc -v localhost 2628 nc: connectx to localhost ...
1
vote
0answers
34 views

How can I embed a console app's output into my X11 desktop?

I'd like to view NetHogs output on my desktop. For example, do any Conky or applets on Cinnamon exist, so I don't need to have a terminal open all the time?
3
votes
1answer
119 views

Fake linux as android device

How can I let my GNU/linux completely mimic an android device when connecting to a wireless Access Point? I explain: I moved to another location and it seems that my android phone and tablet have a ...
0
votes
0answers
24 views

After adding FORWARD NAT rules, cannot connect system eth0

I was trying to make bridge connection between wlan and eth on Centos.. I made Forward and NAT rules and then something wrong with System eth0 connection. It does not connect anymore.. Could you ...
1
vote
1answer
124 views

Why IP address for Linux Bridge which is layer 2 virtual device?

Shouldn't bridge (or a switch) be working without having an IP address? I believe I can have a bridge br0 setup with eth0 and eth1 as members both having no IP addresses. I can't understand why an ...
0
votes
1answer
151 views

Kali Linux airodump Not Finding Networks

When I use the airodump it is not coming up with networks available around me. The chart comes up but nothing inside it, even though there should be about 10 networks around me coming up there is just ...
0
votes
0answers
84 views

Opensuse 13.1 wifi doesn't work (intel k53E laptop)

I downloaded opensuse to dual boot from a CD and got everything installed. At first, my wifi was working. Then I went to school and it stopped working and wouldn't connect to anything even when I ...
2
votes
3answers
95 views

Are there network connections that don't use the WiFii card or the Ethernet port?

I see many connections like when I use netstat, are they all to the internet? Are there any connections to the internet or other things that aren't forthcoming? I guess what I'm asking is what does ...
1
vote
0answers
197 views

Is it possible to prevent eth0 network traffic from accessing eth1 network?

I am not really sure how this is possible but I have a linux(ubuntu 14.04) box with 2 interfaces. eth0 is connected to our lan 192.168.0.* and eth1 is connected to a dlink wifi router on network ...
1
vote
2answers
156 views

How to troubleshooting failing ping to router on a linux box?

I have a home network 192.168.0.x from which I am posting this message, on this network I have a CentOS7 host 192.168.0.3 which is running a DNS server for the network. I can ssh into 192.168.0.3 I ...
2
votes
2answers
262 views

How to use a defined local IP instead of external one

I have a Gentoo Linux server. Server is connected to two networks: internal and external. Internal network ip: 192.168.1.200 External network ip: 192.168.0.2 If I'm trying to make request from ...
10
votes
2answers
520 views

How can I create a virtual ethernet interface on a machine without a physical adapter?

I have a Dell XPS 13 ultrabook which has a wifi nic, but no physical ethernet nic (wlan0, but no eth0). I need to create a virtual adapter for using Vagrant with NFS, but am finding that the typical ...
2
votes
1answer
18 views

Where do I find the OID descriptions for SNMPv2 in Linux?

I was looking at this link here: http://www.debianadmin.com/linux-snmp-oids-for-cpumemory-and-disk-statistics.html and noticed that the OIDs are the same ones I see for the same stats for our ...
0
votes
1answer
147 views

ifconfig not showing changed ip address

I'm trying to configure IP settings on my Raspberry Pi running Rasperian. I edited /etc/networks/interfaces to be: auto lo iface lo inet loopback iface eth0 inet static address 110.76.71.106 ...
0
votes
1answer
896 views

Problems with Dell Wireless 5570 HSPA+ Mobile Broadband card

I've got a new Dell Latitude e7440, and a Dell Wireless 5570 HSPA+ mobile broadband card. I cannot get the broadband card to work. I can see the card: # lshw .... *-network DISABLED ...
1
vote
0answers
77 views

where is network layer protocols source code [closed]

that's all I can find tcp source code on my Ubuntu, also the place of data link layer is on the network interface. So where is network layer protocols source code on ubuntu ? Also I am looking for ...
2
votes
2answers
72 views

How can I use avahi without a network connection?

How can I test software that uses avahi while my laptop is disconnected from any router? All of the services run on the same machine, so Avahi would be advertising an IP address of 127.0.0.1 for all ...
0
votes
1answer
159 views

Static IP addressing issue in Ubuntu on BeagleBoneBlack Rev C

I have my BBB configured to use a static IP address using the following in the file /etc/network/interfaces: allow-hotplug eth0 iface eth0 inet static address 192.168.0.1 netmask ...
0
votes
1answer
115 views

Ethernet does not work at all

I haven't used my NIC for some time, and now it doesn't work anymore, at all. I can assign IP addresses to it manually (sudo ip addr add 192.168.2.155/24 broadcast 192.168.2.255 dev eth0, for ...
1
vote
2answers
78 views

Debian VM Can see other computers on the network but can't connect to the WWW

Similar to this SU question: http://superuser.com/questions/667631/network-is-unreachable-when-attempting-to-ping-google-but-internal-addresses Actually, it's pretty much the same base issue. I went ...
0
votes
4answers
62 views

How do I find my Raspberry Pi on a big LAN?

I'm a college kid on a WPA2 Enterprise with a Raspberry Pi on ethernet. How do I find this device on the network? I could try running arp -a logging results to a file, connecting my Pi, and then ...
1
vote
0answers
51 views

Does PPPoE connection have IP before authentication?

I am debugging a connectivity issue with my internet connection provider. I have a PPPoE type of connection. I am working on configuring my router to connect over PPPoE connection. Please note that ...
0
votes
2answers
615 views

Can't access mail server through SMTP

I'm trying to send email from a server. Testing on my local machine works fine but on my production Ubuntu server, the webserver fails when trying to send email. I'm using GMail as my SMTP provider ...
2
votes
0answers
96 views

Wait for a network device to come up before bringing another network device up on boot?

I'm in the middle of setting up my Raspberry Pi running Raspbian as a bridge between my university's wireless network (which requires WPA2-Enterprise authentication) and my private wireless router ...
4
votes
1answer
392 views

How can I most simply transparently bridge traffic between wlan0 and eth0?

I am looking to do this on a Raspberry Pi, but I don't mind which operating system I have to install, so the easiest most out-of-the-box solution for Pidora (Fedora 20 Remix), Raspbian (Debian) or ...
4
votes
2answers
107 views

Redirecting loopback traffic through a router

For some tests purposes, I am running multiple socket-based applications on one machine and want to simulate "real" network conditions between them. I thought the simplest would be to redirect all ...
0
votes
1answer
295 views

Unable to ping CentOS virtualbox

I have created a virtual machine for CentOS in VirtualBox using an NAT connection (It wont work under Bridged). Now the problem is I can ping from CentOS to my IP on Ubuntu with no problem but I ...
1
vote
0answers
21 views

Two way internet sharing configuration (swiching modem from one machine to another)

I have: One Raspberry Pi with Raspbian (distribution based on Debian), with one enthernet interface One laptop with windows, with one ethernet interface One USB modem Ethernet cable between Pi and ...
1
vote
2answers
75 views

Logging in to VirtualBox via SSH

I'm starting with VirtualBox and Linux on a Windows machine. I can log in to Linux using the Virtual Box command line but I want to do something pretty easy: log in from an external (not virtualbox) ...
1
vote
1answer
59 views

How to permit any user (mysql, apache, etc) to use any TCP or UDP port?

How can I ensure that all ports are open to any user? Currently ports 1 to 1024 are reserved for "root" only. Although I am not sure why "apache" is capable of using port "80" if this port too is ...
1
vote
1answer
283 views

Reboot when no network connection does not work!

I have a Raspberry Pi that I use as a NAS for my local network. It works fine, but when I turn off the router to which the pi is connected, it permanently loses the connection. To be able to connect ...
0
votes
0answers
72 views

How to merge two network interface in one?

I have two network interface on my router: wlan0 and wlan1. First for 2.4Ghz and second for 5Ghz. Also i have Coova-chilli with setting HS_LANIF=wlan0. Therefore captive portal (chilli) work for only ...
2
votes
1answer
153 views

Fix “Route hash chain too long” without restart

On our production server (ubuntu 12.04, 3.2.0-63 kernel) routing cache reached its capacity. Modifying rhash_entries is out of the question, since it is a kernel boot param, and we can not restart the ...
1
vote
1answer
36 views

Re-enable route cache

In my kernel log I found: lo: 5 rebuilds is over limit, route caching disabled I know what triggers route cache rebuilds (too long hash bucket chains), but what exactly gets disabled? Which device? ...
0
votes
0answers
16 views

Proxy for certain networks

Is it possible, on a system using NetworkManager, to configure a system-wide proxy if I am in a certain wifi-network, but not otherwise? It would also need to log in to the proxy with a username and ...
2
votes
1answer
31 views

Absolutely jail a user with minimum IP, file, & command rights

I am trying to secure a custom application as much as possible from outside tampering. I've seen many pages on jailing a user, but they usually include many exceptions, and I want to lock down this ...
1
vote
1answer
89 views

curl timeout troubleshooting

I tried to curl popular websites e.g. curl google.com or curl google.com:80 and there is always a timeout error. Some troubleshooting steps performed: Able to curl localhost with response Able to ...
1
vote
1answer
97 views

Cannot ping machine on eth0; Pings fine on wlan0; Centos 6.5 on Dell D610

I recently installed Centos 6.5 (32 bit) on an old Dell D610. It has both a lan port and a wifi. When I assign the wifi a static IP, I can use it as a server, connect to it from other machines etc ...
1
vote
2answers
74 views

netcat to capture ethernet

How can I make sure the result of the following command: nc eth0 &> capture.txt would capture the data + errors transmitted via eth0?
2
votes
0answers
70 views

How does ssh work when client and host are on the same machine? [closed]

I illustrate my question with the help of docker containers but this example is orthogonal to the rest of the problem. In fact any program that allows the use of bridge interfaces and ssh would do. I ...
3
votes
1answer
204 views

What is the difference between hostname, hostname --fqdn, and hostname -A

I have a machine I changed the hostname of. I changed it in /etc/hosts, /etc/sysconfig/network, and with hostname command. hostname returns the correct shortname, hostname --fqdn returns the expected ...
5
votes
1answer
258 views

How to rollback network configuration changes done over SSH in case of failure?

I'm about to change iptables configuration and interface speed and duplex settings over SSH. What are the possibilities to rollback the changes in case of host becomes unreachable? I guess simple: ip ...
1
vote
0answers
81 views

How to route network in order to use internet on CentOs?

I have 2 computer in local network which have CentOS both. One has wireless card which can use internet connection. Other computer does not have internet connection. I want to route ip addresses in ...
1
vote
1answer
99 views

repair the static route to allow traffic to right place

I recently was taking an online test and I got the below question. The server has been configured with a TUN device tun-aib0 that acts as an endpoint for a VPN tunnel. The IP address of the device ...
1
vote
1answer
55 views

Unable to access an http sevice forwarded using ssh

I forwarded a port from a remote server (which has Tomcat running on it) to a local port on my machine. Say, if the remote server address is http://myremoteserver.com:8080, I forwarded the port to ...
3
votes
3answers
130 views

How can unix computers find each other by hostname?

I have a home-network with several windows and Linux machines which have samba installed. on windows I can find each other computer fine via its hostname. however on a linux computer I cant find any ...
1
vote
2answers
1k views

cannot find device “eth0” [closed]

Hey Arch linux users out there! I am new to arch linux( coming from ubuntu), and have just installed arch linux on my machine. After rebooting I wanted to install some packages using pacman -S, but ...