the IP protocol and IP addresses

learn more… | top users | synonyms

3
votes
1answer
472 views

How can I bridge two interfaces with ip/iproute2?

I know how to create a bridge using brctl, but I have been advised not to use this anymore, and to use iproute2 or ip instead(since brctl is deprecated presumably). Assuming this is good advice, how ...
3
votes
3answers
367 views

Unable to reconnect 3g connection after new IP was given

I use Debian Jessie 8.2 and I am using a 3G connection using this modem. The 3G connection works fine, except after 24 hours the connection drops and I cannot reconnect. If I reboot the computer, ...
0
votes
0answers
66 views

How to start and stop a libreswan connection

I have a connection configured on my libreswan instance on two machines. The connection start automatically when I start the pluto daemon, I have try other settings, but the connection also starts if ...
2
votes
1answer
170 views

Get the external IP address in shell without dig in 2016?

This question: "How can I get my external IP address in bash?" Solves the question with a call to dig: dig +short myip.opendns.com @resolver1.opendns.com; that is the fastest resolution possible, ...
3
votes
2answers
249 views

IPv4 link-local address in Linux

I remember that in Windows XP, when DHCP client did not receive an IPv4 address from DHCP server, the host assigned itself an IPv4 link-local address from 169.254.0.0/16. However, I have never seen ...
2
votes
2answers
3k views

lts is there a way to enable sleep mode and wake on lan?

I was wondering if it were posible to make my server go to sleep after a set period of time, but still be listening for lan requests. I use my server as a media server that might get used 3 or 4 hours ...
4
votes
3answers
2k views

What are the interface prefix meanings in ifconfig?

I'm not sure if these have a name, but on most computers I use the interface prefixes are usually: eth- : Ethernet/Wired wlan- : Wireless/WiFi However, on my ASUS RT-N56U, I have the following: ...
1
vote
1answer
584 views

Can nmap display only hosts with specific ports open?

Can nmap list all hosts on the local network that have both SSH and HTTP open? To do so, I can run something like: nmap 192.168.1.1-254 -p22,80 --open However, this lists hosts that have ANY of ...
0
votes
2answers
48 views

Unable to connect remotely to custom application

I've built an application that listens on the localhost address and a specific port, lets say port 11001. Its on a remote machine with CentOS. I currently have a python script on my local machine that ...
2
votes
4answers
152 views

Finding Servers Public IP and Allowing Remote Access

I want to turn a computer that I have lying around into a file server. The problem is that I cannot find my public IP. I have used services such as myip or even google, but they all point to the IP of ...
1
vote
1answer
267 views

Virtualbox - how to give Internet access and internal network access to two VMs?

I made two Virtualbox virtual machines, CentOS 7 latest iso. I gave them each 2 network interfaces, one NAT and one "Internal network" in order to get them to talk to each other and have Internet ...
4
votes
5answers
500 views

How to log Internet connection drops

I need to execute a script as soon as my raspberry pi gets connected to the Internet. However I was wondering if there was a better way than just pinging Google every minute or so. My problem is that ...
2
votes
1answer
116 views

Why doesn't FTP work through my ssh tunnel?

Computer A (assumed that ip is 44.44.44.44)can ftp the host 130.89.148.12. ftp 130.89.148.12 Connected to 130.89.148.12. 220 ftp.debian.org FTP server Name (130.89.148.12:debian8): anonymous 331 ...
0
votes
1answer
32 views

OpenVPN to access restriced pages

I am looking for a method to go out with different ip in order to access some sites that are blocked by my local provider(I need to write scripts to retrieve data from thos pages).On ...
31
votes
13answers
38k views

How to get my own IP address and save it to a variable in a shell script?

How can I get my own IP address and save it to a variable in a shell script?
1
vote
2answers
5k views

How to find MAC or IP address of a device connected to the same Ethernet bridge?

I have the following topology: DeviceX ------ | DeviceX bridge with two Ethernet cards (created with bridge-utils) ---------------- router | ...
1
vote
1answer
68 views

Nothing happens when trying to add/set default gateway

I'm connected to a network using VPN (Managed byt NetworkManager, Fedora 23), and I want to route all traffica via the VPN network. But for some reason nothing happens when I run ip route add or ip ...
3
votes
2answers
864 views

Bash: Permission denied when trying to echo data directly to Network

I am trying to send characters directly to the network stack as explained in this thread. Even when the process work OK under CygWin (Windows), the same lines do fail on Ubuntu v14.04: luis@...
1
vote
1answer
79 views

Telnetting the local port working but trying with ip not working

My question is similar but opposite to to Telnetting the Local port not working but trying the ip working For me, telnet to the local port works but trying with IP does not work :( I am running ...
4
votes
1answer
30 views

How can I tell which IP address is used to connect to another machine?

I have several computers that are multi-homed, and have different static IP addresses for each of several network connections. How can I tell which of these IP addresses is used when I'm connecting to ...
3
votes
1answer
80 views

Two Virtualbox systems with same IP address

I need to test an issue with nfs so I spun up a couple of VirtualBox VM's on my system. One is RHEL7, another CentOS7. Each has a unique MAC address when viewing settings> network. Both VM's boot ...
0
votes
1answer
591 views

server can't find xxx.xx.xxx.192.in-addr.arpa:NXDOMAIN

$ORIGIN xx.xxx.192.in-addr.arpa. $TTL 86400 @ IN SOA dns1.testserver.com. hostmaster.testserver.com. ( 2001062501 ;serial 21600 ;refresh after 6 hour 3600 ;retry after 1 hour 604800 ;expire ...
2
votes
1answer
3k views

ICMP gives host an impossible redirect

I am having trouble with forwarding on a system which hosts a few headless VirtualBox VMs. I have not changed anything but the configuration has stopped working. The VMs have IP addresses on their own ...
2
votes
3answers
631 views

Validating IP addresses (IPv4 and IPv6)

Quite simply I'd like to verify that a string represents a valid IP address in a bash script. I think like many others I've fallen into the pitfall of trying to do this with a regular expression; ...
2
votes
2answers
198 views

iptables: No chain/target/match by that name - adding SSH ATTACK rule

I have a problem with adding rule against brute-force SSH attacks. I try to do it in the following way: iptables -F iptables -L iptables -N SSHATTACK iptables -A SSHATTACK -j LOG --log-prefix "...
2
votes
2answers
125 views

Find IP owners from apache log file

I have the top 10 IPs making the most requests and the number of requests made from Apache log file example. I used this bash command to handle a request: cat access_log|cut -d' ' -f1|uniq -c|sort -r|...
1
vote
1answer
208 views

FreeBSD: adding ip alias to interface breaks network on primary ip

I am trying to add an alias to my network card (I would like to use jails) on my FreeBSD box. It is running version 10.2-RELEASE-p7 (generic amd64 kernel). The machine is running in a Hyper-V virtual ...
1
vote
0answers
126 views

Not permitted to add eth0 to bond0

I'm trying to add an interface to my bond0 but I always get the error. sudo ip link set dev eth0 master bond0 RTNETLINK answers: Operation not permitted I already tried it with sudo and with ...
1
vote
0answers
375 views

ip link add gives me an error that it's not supported

I would like to set up a bridge with iproute2 like this: Adding bridge : ip link add name br0 type bridge Bringing bridge UP : ip link set dev br0 up Adding interface to bridge : ip link set dev eth1 ...
26
votes
1answer
29k views

What is kernel ip forwarding?

I have seen on many blogs, using this command to enable IP forwarding while using many network security/sniffing tools on linux echo 1 > /proc/sys/net/ipv4/ip_forward Can anyone explain me in ...
2
votes
3answers
191 views

Arithmetic on variable containing ip address

I've got variable network="198.168.1.x" # for ex. 198.168.1.254 I want to create new variables: next_serv="198.168.1.(x-1)" # for ex. 198.168.1.253 max_host="198.168.1.(x-2)" # for ex. 198.168....
2
votes
1answer
103 views

Grepping and sedding IP from ip addr show

I'm trying to get just the local IP of my Arch VM. I've managed to get just the line containing what I want with grep, but I also want to trim it down with sed. inet <<192.168.0.16>>/24 ...
1
vote
1answer
635 views

Zookeeper DNS name problems with leader elections when migrating from Windows to Debian

I am migrating a kafka/zookeeper cluster on Windows to Debian wheezy. Java version: 1.7.0_80 Debian version: 7.9 Zookeeper version: 3.3.5+dfsg1-2 0 Kafka version: 2.10-0.8.2.1 If I configure ...
0
votes
0answers
21 views

How do you interpret these routes? or more or more specifically, what is scope link?

I don't understand completely what these routes mean: [root@samplehost ~]# ip route show ...#default route here 10.68.172.0/24 dev eno33557248 proto kernel scope link src 10.68.172.20 169.254.0.0/...
3
votes
1answer
696 views

Use two NICs for different subnets

In my office I have use a system with two network cards. I want to use both at same time. I have four subnets in my LAN. I want to route two subnets (192.168.2.0 and 192.168.4.0) through eth0 and ...
0
votes
2answers
31 views

Which ip is used when two net cards all can be used?

There are two net cards in used status in my pc. ifconfig eth0 Link encap:Ethernet HWaddr e0:3f:49:57:4b:d1 inet addr:192.168.1.3 Bcast:192.168.1.255 Mask:255.255.255.0 ...
0
votes
1answer
48 views

Adding route entries to the routing table

I have a device that has a default IP address of 10.1.1.102 with netmask 255.255.255.0. Rather than changing it, I tried to add a routing entry to my routing table using route add. sudo route add -...
2
votes
1answer
42k views

Unable to ping gateway & other Linux boxes on same network

I'm somewhat new to Linux, but I'm trying to network a few Linux machines. I can't seem to be able ping the gateway or the other Linux machines. My scenario: I have a few Linux boxes set up on a 10....
0
votes
2answers
58 views

Show netmask using ip tool

I would like to know how to get the mask of a network interface. With ifconfig it is very simple, but I have to use the ip tool, and ip addr show is not showing me what I want. Here is an example ...
1
vote
1answer
19 views

Translate from IPv4 to IPv6 and backwards

I have the following situation: Two computers, one running Debian, the other one Ubuntu. The first one is connected to the internet via an interface which somehow only allows IPv6-connections, and ...
0
votes
0answers
20 views

ip-tunnel: “Tunneling with a fixed ttl always makes pmtu discovery” - why?

The manual page for ip-tunnel says: ...fixed ttl is incompatible with [no PMTU discovery] option: tunneling with a fixed ttl always makes pmtu discovery. What is the reason for this? I do not see ...
1
vote
0answers
30 views

How to force dhcpcd to forget an old static address after editing dhcpcd.conf?

How can I force dhcpcd to forget a previously configured static address after setting a new one in /etc/dhcpcd.conf? I changed: static ip_address=192.168.1.1/24 to static ip_address=192.168.1.2/...
1
vote
1answer
632 views

Virtual Box guest on different subnet than host

I currently have my Debian VM using NAT and it is on subnet 10.0.2.x where my host is on 192.168.0.x how can I get my guest on the same subnet as my host? Host: Ethernet adapter VirtualBox Host-...
5
votes
2answers
2k views

How safe is it to change the Linux Ephemeral Port range

I see the following ephemeral port range on my Linux box. sysctl net.ipv4.ip_local_port_range net.ipv4.ip_local_port_range = 32768 61000 I want to extend the port range to start from around ...
0
votes
0answers
70 views

linux to linux IP MASQUERADING failed (can't ping ip server)

I'm new in linux, i'm trying to IP MASQ. So the diagram is like linux A is connected to HUB and Internet, and linux B is connected only to HUB. In linux A i have eth1 (10.10.10.5) and eth0 (192.168.1....
2
votes
1answer
71 views

How do you add a virtual network IP address from the kernel command-line?

I would like to add a virtual IP address, something you normal do with: ifconfig eth0:0 192.168.1.1 (or via /etc/network/interfaces). But, I'd like to do it from the kernel command-line, which has ...
1
vote
0answers
31 views

Any potential problems when configure multiple NIC for isolated networks to have same subnet?

System I have an ARM Linux (kernel 3.17) for field use and it has multiple NIC, say eth0, eth1, and wlan0. On the left side, I need to use a PC0 to configure the ARM Linux so that it can change it's ...
1
vote
1answer
85 views

Forwarding traffic coming from SSH tunnel to VPN tunnel on a Linux device

I want to route network traffic that comes from one end of an ssh tunnel (constructed by ssh dynamic port-forwarding) into one end of a VPN tunnel. Given four Linux devices A, B, C and D, for ...
1
vote
2answers
86 views

Why are `netmask`, `network`, `gateway` and `dns-nameservers` needed for setting up a static IP?

When setting up a static IP, you need to change /etc/network/interfaces to: auto eth0 iface eth0 inet static address 10.253.0.50 netmask 255.255.255.0 network 10.253.0.0 gateway 10.253.0....
0
votes
1answer
41 views

Letting a device access the Internet through an Ethernet port via a laptop [duplicate]

I have Internet access to my laptop, over Wi-Fi. I have connected a device with an Ethernet port (with an Ethernet cable from my laptop to the device), and set up a local area network between the two, ...