Questions tagged [ip]
Questions about the IP protocol and IP addresses. For Linux ip utility related questions, use iproute tag instead.
896
questions
0
votes
2answers
24 views
Centos: Obtain MAC address of a local machine
I have a local network with many machines. From a CentOS server I need to obtain the MAC address of specific IP (and need to automate this for several hundred IPs).
I have tried ping + arp -a, but it ...
0
votes
0answers
12 views
Connect to VPN server via VPN client which is a NAT instance
Main question is how to connect to a vpn server via a vpn client which is a NAT instance, let me describe about it.
Scenes 1:
I have a group of service instance(ubuntu 18.04) named A
One instances ...
0
votes
0answers
29 views
route via default gateway of the interface
I have a gRPC client (works on top of HTTP2). I want to route the connection via different interfaces at different times. I generally create an instance of the client and set a route to force gRPC to ...
0
votes
1answer
12 views
How to automatically add route when connecting to a wireless lan?
I have a Beaglebone Black device that uses Debian 9.9 Linux (without UI, I am using terminal for this). (latest image for Beaglebone Black https://beagleboard.org/latest-images)
I enabled and ...
0
votes
1answer
36 views
Show IP address of currently mounted CIFS share
A linux client mounts a Windows share resolved by FQDN configured in /etc/fstab like this:
//fqdn.windows.share/theShare /local/mount/point cifs [...]
Due to infrastructure changes the IP address of ...
0
votes
0answers
27 views
SoftEther VPN Client IP Routing on Linux
I'm having some problems to establish routing tables on my linux client machine using a Site-to-Site(LAN-to-LAN) VPN (softether). It works great for Windows clients , but for linux I don't know how to ...
0
votes
0answers
21 views
force network routing out different interface
I have 3 interfaces: eth0 accepts vpn connections from two networks, eth2 should route traffic from netA through it, and eth3 should route traffic from netB through it.
netA eth2
&...
0
votes
0answers
9 views
SMTP Relay for single IP
I have a two IPs, 172.25.0.1 and 172.25.0.2, and one relayhost smtp.example.com.
Now I try to send mail via IP 172.25.0.1 and it's taken the smtp.example.com relay. It's working fine, with no issues ...
0
votes
0answers
21 views
entry in arp table present but still requests
Working with a linux machine and a microcontroller with the lightweight IP stack on it. Trying to get a ping going between them and facing some issues. The first time when a ping is initiated from the ...
0
votes
0answers
6 views
How to setup a network card IP to be dynamic first DHCP, but to have static IP as fallback in CentOS/RHEL?
In CentOS7/RHEL7, ideally already via a kickstart configuration a network card should be setup in a way to attempt getting dynamic IPv4 address via DHCP and if no DHCP lease is available (after some ...
3
votes
2answers
55 views
Why does the interface have an IPv6 address with IPv6 disabled?
I want to use my interface with a single IPv4 address and IPv6 disabled.
IPv4 is configured on Manual, with a static IP without Gateway and Netmask 255.255.255.0. User this connection only for ...
0
votes
0answers
4 views
Problems routing Internet traffic from client through host w/multiple IP address on same i/f
Need routing configuration advice (preferably with commands):
I'm trying to somehow forward Internet requests originating on the client through a host (over 192.168.200.0 network) to an Internet ...
0
votes
1answer
31 views
Accessing CentOS server from external IP
I have been trying to set up a centos 7 server. There is no problem in accessing the server from the same network. But when I try
$ ssh -x user@ipAddressofServer
from an external network, It ...
1
vote
1answer
37 views
Blacklist IP file for `ipfw`?
My /etc/rc.firewall file contains the following additional lines created by me, with the purpose of banning attacker's DDoSers IPs:
${fwcmd} add deny ip from 122.228.19.80/24,\
...
0
votes
1answer
25 views
Question related to TCP/IP buffering in linux
I have been trying very hard to find about buffers used in TCP/IP as part of packet transfer in linux. More i read, more i get confused. Below given are questions i have. Can someone help me figure it ...
0
votes
2answers
95 views
ufw not working on debian
I'm trying to install ufw on my debian buster machine and get it to work. I already installed it using apt-get and if I try to do so again it says
> ufw is already the newest version (0.36-1)
So ...
0
votes
0answers
7 views
Setting “datastream_hostport”
First off I'm new to all this, so apologies if this question has already been asked. I have multiple computers working over a network, more specifically one computer will be responsible for running ...
0
votes
1answer
49 views
How to find IP address for SSH target machine?
I am trying to set up an SSH tunnel into a small Lubuntu server that I have created, and I am unsure about how to actually find the IP address that I will use to connect to it from my laptop. The SSH ...
0
votes
2answers
51 views
Seeing frequent log entries for martian TCP packets (potentially causing performance issues)
I am seeing a nearly constant stream of these entries in its service node logs, not sure what they mean? I have read up on this and some say that it is a security issue and others says it is nothing ...
2
votes
1answer
68 views
Debian ignores static IPv6 configuration
Original post
I'm trying to configure a static IPv6 address for my Debian container (running on LXD) but the system keeps ignoring my configuration.
Currently my /etc/network/interfaces looks like ...
0
votes
0answers
14 views
metric not working with ip route
I'm trying to make a dummy network interface as a fallback when a real network doesn't exist for an embedded device. The embedded application spams UDP data which is fine as long as the ethernet ...
0
votes
1answer
95 views
How to configure IP Forwarding
I have a device DEV1 which should communicate with device DEV3, however in the middle there is DEV2.
My understanding is that I need to use IP Forwarding in DEV2 and edit route tables on DEV1 and ...
0
votes
1answer
62 views
2 hosts on same subnet route thru 3rd host?
Here's the setup:
Host A : 192.168.0.5/24
Host B : 192.168.0.6/24
Host C : 192.168.0.1/24
All connected via switch.
I want to monitor traffic between A and B by setting a route on A and B to use C ...
0
votes
0answers
52 views
Host key verification failed after changing MAC address
I changed my MAC address, I believe using sudo ip link set dev interface address XX:XX:XX:XX:XX:XX, in order to be assigned a new local IP address to fix some network issues I was having. This worked ...
1
vote
1answer
36 views
How can I find the source of a ping request within a device?
I have a linux-based cellular device that every 4-6 weeks begins pinging Google IP addresses 10-12x every minute. This increased pinging begins and ends seemingly randomly, lasts for a few days before ...
0
votes
0answers
57 views
EC2 SSH connection refused after changing elastic IP and reboot
I've browsed several dozen copies of this question but none of them seem to fix my situation.
I have already checked:
permissions on pem key (it worked before)
checked correct new ip in ssh config
...
4
votes
1answer
149 views
“RTNETLINK answers: File exists” after trying to ifup interface
I have 3 different blocks which I'm trying to configure. They used to work normally when I would add all the addresses of the block manually (ip addr add) but I learned that I can just add the entire ...
0
votes
0answers
131 views
No /sys/kernel/config/usb_gadget
I followed https://events.static.linuxfound.org/sites/events/files/slides/USB%20Gadget%20Configfs%20API_0.pdf and complied the kernel with
Device drivers
[*] USB support
<M> USB Gadget ...
2
votes
4answers
135 views
Read file and print out ip-address to another file
I have big file that holds something like 40000 rows of domain names.
I would like to read that file and use dig (or something else) to look up the IP addresses of the domain names in the DNS, and ...
0
votes
1answer
38 views
Top 10 IP by request across two nodes
I have two web servers, and I want to know the top 10 ips sorted by the number of requests.
The webservers are Apache based, so I need to look at an access.log file.
The problem is since these files ...
0
votes
1answer
120 views
Ip address is of 32 bit, which means 4 bytes. Yet all answers to question on 13 root dns servers say otherwise [closed]
All of the articles I read that explains why there are 13 root dns servers saying each ip address takes 32 bytes and hence (13 x 32) = 416 bytes leaving up to 96 bytes for other protocol information. ...
0
votes
1answer
326 views
Linux IP bridge and vlan_filtering
I'm using DSA in Linux to support an ethernet switch (KSZ9897). The switch is behaving but I'm having trouble setting up the bridge vlan filtering features through Linux (kernel 4.19).
I create the ...
0
votes
1answer
53 views
TCP clients connecting outside of defined port range
A TCP server runs on an Ubuntu 18.04 box.
Here's the local port range configuration on this box:
blah@blah:~# sysctl net.ipv4.ip_local_port_range
net.ipv4.ip_local_port_range = 32768 60999
The ...
0
votes
1answer
105 views
How to verify static LAN IP assignment to USB0
A Raspberry Pi 3B+ is configured
with Raspbian
with a working wifi: pinned to a static LAN IP address
Per the procedure: a static IP 192.168.42.42 assigned to the rPi's USB0 interface. Append: ...
0
votes
1answer
95 views
What do IP adresses for eth0 and eth1 stand for?
I sshed to my vagrant machine.
System load: 0.13 Processes: 169
Usage of /: 6.6% of 61.80GB Users logged in: 0
Memory usage: 76% IP address for ...
1
vote
2answers
121 views
Destination Host Unreachable after switching to static ip
I recently switched to a static IP, and the first time I restarted my computer, I lost my internet connection. Help!
More details
(For the record, I'm on Debian 10.)
I can ping localhost, but not ...
0
votes
0answers
21 views
How does this specific routing rule works?
ip rule add from ip.ip.ip.ip table 128
ip route add table 128 to ip.ip.cidr.cidr/range dev eth0
ip route add table 128 default via gate.gate.gate.gate
Why is table 128 specifically? Why is there a ...
1
vote
1answer
30 views
ip monitor : responding to events
I want to run a script in response to certain network events and to do this I am monitoring network routes using
ip monitor route dev enp3s0
ip monitor waits for events and prints them as they ...
1
vote
1answer
34 views
listening for changes in network state
I have a panel label displaying the external IP. I get this through:
wget -qO- http://ipecho.net/plain
I want this label to be sensitive to network changes. For example, a VPN up or down, or a ...
0
votes
0answers
15 views
nslookup ip query
I am member of the domain at work, and we have our local DNS resolver.
Sometimes I'd like to know the hostname of a specific IP, so I run the IP through nslookup which uses our domain-controller/DNS ...
0
votes
1answer
167 views
Where is the documentation for the IP variable in initramfs.conf?
Multiple sources, including this one, mention using the IP variable in initramfs.conf to set a static IP address in the pre-boot environment, and I have used this successfully in the past. However, ...
0
votes
0answers
25 views
Cannot understand behaviour of ifup/ifdown and /etc/init-d/networking
I want to connect an IP camera to my laptop which runs Ubuntu. The set up looks like this:
Once I have the physical connections, I change my /etc/network/interfaces file from:
auto lo
iface lo inet ...
-3
votes
1answer
55 views
File check for IP change
I need to update a file which contain my external ip address on a server via scp.
Before updating the file I want to ensure that it contain an actual IP address else it must not be updated on the ...
0
votes
1answer
37 views
Alternative way to configure IP address
I am setting up an embedded linux device which should grab its IP-address and its MAC address at boot from files in the filesystem. Lets say there is a file /root/ipaddress with the only content "192....
0
votes
0answers
67 views
How to open SSH port 22 to connect medusa to my router ip
I've been learning how to brute force my own router password through medusa and I've encountered the following error:
NOTICE: ssh.mod: failed to connect, port 22 was not open on 192.168.0.1
note ...
0
votes
1answer
28 views
How can I make a LAN with a wifi adapter in linux?
I am not interested in sharing internet connection, I just want to make an AP that multiple devices can connect to and communicate with each other.
I have a USB wifi adapter. How can I configure it ...
1
vote
0answers
74 views
Running ip or ifconfig from inside an UDEV Rule
I am trying to create an udev rule from which I would like to invoke ifconfig or ip to change ip addresses from a usb kernel network interface. To do this, I created:
ACTION=="add", SUBSYSTEM=="net", ...
0
votes
1answer
53 views
How can I restrict my computer's ability to connect to other ip's
I have a comma seperated list of IP addresses in a text file like this:
192.xxx.xxx.xxx,213.www.www.www,255.yyy.yyy.yyy
Can I block my Ubuntu 19 from connecting to those IP addresses? If yes, How?
0
votes
0answers
21 views
Finding which process is modifying the network
I want to find which of the running processes are modifying the network configuration in Android/Linux. I do an "ip route" configuration but it is gone after some time. I check the network ...
0
votes
0answers
39 views
Giving a network interface multiple names
We have a large group of servers, each with multiple interfaces. The system admins need to store information on the machine to indicate which multicast groups should be used with which interfaces.
It'...
