I discovered only last week with help on here that I could have the OS Architecture (32/64) stored in a variable like this:
arch=$(getconf LONG_BIT)
I am hoping that I can use a similar method for local IP address:
ipaddress=$(????)
So that any occurrences of $ipaddress will be replaced with "192.168.1.100" or whatever the local IP might be
Unfortunately, it is not possible to extract the IP address of the system from the sysconf sub-system.
It is possible to have several IP addresses associated with the interfaces on a Linux system so there is no way to determine which IP address is the 'correct' one.
You could use the following shell snippet to list the active IP addresses on the system:
ifconfig | grep 'inet addr' | awk '{print $2}' | cut -d ':' -f2
On my system this lists the following IP addresses:
192.168.1.12
127.0.0.1
If you see similar output, it means you've only got a single active interface along with the local loopback, so you can add |grep -v 127 to the previous snippet to filter out the local loopback address.
Related
I know of ls /sys/class/net to get all the available IP interface names, and also cat /proc/net/fib_trie to get all the IP addresses, but how do I match between them?
My desired result is a list of IP interface names and the IP address assigned to every interface name, similar to the info showed by ifconfig but that can be applied on any Linux distribution.
for example:
enp4s0f1 5.6.7.1
enp6s0 2.2.2.1
My desired result is a list of IP interface names and the IP address assigned to every interface name, similar to the info showed by ifconfig but that can be applied on any Linux distribution.
Try this:
ip addr | grep inet | grep -v "inet6"
Using the ip system utility. You're not using /proc/ or /sys/, but it'll work on any distro with ip on it, which is most of them.
Update: to make it look a bit easier on the eye, use this:
ip addr | grep inet | grep -v "inet6" | awk '{print $2 " " $8}'
How do I strip out an IP address the resultant line from arp which includes the correct MAC address and the IP address the machine is found at with something like
arp -a | grep "70:d1" > address_file.txt
This gives me the following output:
? (10.0.0.9) at b8:27:eb:3:79:d1 on en0 ifscope [ethernet]
I've tried various incantations of sed with no luck. The latest attempt is:
cat address_file.txt | sed 's/(\d{1,3}\.){3}\d{1,3}//p' address_file.txt
There is probably something procedurally wrong that I'm doing, but I'm running low on patience as this was supposed to be a quick and dirty hack to provide some automation. I would also note that I am using a Mac running OS Mojave as I have read that they are some regex differences between BSD sed and other versions of sed.
I should note that I perform a nmap of the subnet because the arp entry can be stale and the machine will no longer be online or a different address but has produced no traffic.
Use the parenthesis to extract what is inside:
arp -a | sed -e s'/.*(\(.*\)).*/\1/g'
I am trying to get this function to file .bashrc
This is my function :
function my_ip() {
echo "internal or external?"
read -r choise
if [ "$choise" == "internal" ] ;then
echo "please enter the name of the card that youare using at";
read -r card ;
ifconfig "$card" | grep 'inet addr' |cut -d':' -f2|cut -d ' ' -f1;
else
wget -qO- http://noc.co.il |grep "var VisitorCountry" | awk '{print$4}'|cut -d '"' -f4;
fi
}
My goal is that the function will quickly give me my IP by choosing internal or external
if I want to automatically displays the network card ("without the need to ask Which network card do you use(The computer automatically detects which network card the user uses and will put the name as a variable at the right commend for internal IP , how can I get him to identify what card the user use(WLAN0 WLAN1 etc.) ?
A system can have more than one IP address. Which one of them is the one you are looking for? You did not specify that.
There are multiple questions related to finding IP addresses with bash:
Find internal IP address
The accepted answer uses a deprecated option for hostname; the second answer is the more correct one IMHO.
In bash, is there a way to find the IP address for all interfaces?
Find IP address for my system
Bash script to find all IP addresses
If none of those float your boat, consider closing this question and posting a new one with more precise phrasing what you are looking for.
I have a Linux server with multiple network namespaces defined:
# ip netns list
qdhcp-7dedbd4e-2265-4aa2-baac-add4e341dd18
qdhcp-851379ba-1d51-4e45-8e50-b756e81c0949
qdhcp-a19927c5-83b4-4bb4-a8b8-f21fdb5e004b
qdhcp-b94605ff-b0e2-4cfe-a95e-3dd10208a5fb
... ...
Each namespace contains one or more virtual network adapters - in this case, it's a TAP device:
# ip netns exec qdhcp-7dedbd4e-2265-4aa2-baac-add4e341dd18 ip route
192.168.168.0/24 dev tapda4018ab-b7 proto kernel scope link src 192.168.168.2
169.254.0.0/16 dev tapda4018ab-b7 proto kernel scope link src 169.254.169.254
default via 192.168.168.1 dev tapda4018ab-b7
Now let's say I know the name of the adapter - tapda4018ab-b7 - but I don't know the namespace it belongs to. Is there a way to look it up without checking namespaces one by one? Is there a generic Linux command to do this? Or at least OpenStack Neutron-specific command?
According to this man page http://man7.org/linux/man-pages/man8/ip-netns.8.html you could run the exec command on all namespaces but I tested it on an ubuntu trusty servers and it will not accept "-all" as an argument. So the only way I know to get such an information is via a small bash script. I made one that could certainly be improved as my scripting skills are rather basic, but it will do the work:
#!/bin/bash
i=$(ip netns list | wc -l)
counter=1
while [ $counter -le $i ]; do
ns=$(ip netns | head -$counter | tail -1)
ip netns exec $ns ip route | grep $1 | grep proto
let counter=counter+1
done
You can then launch the script using as sole argument your tap device as in the example bellow:
root#columbo:~# ./list_all_namespace tap8164117b-e3
5.5.5.0/25 dev tap8164117b-e3 proto kernel scope link src 5.5.5.3
If you do not provide an argument it will give you an error.
If I understand Neutron correctly (which is a big if - my only experience is with a fairly limited toy installation of Kilo/2015.1.2), you should be able to track through neutron's database to figure out the netns you're looking for
I believe your tap interface would be named using the first 5 octets (10 characters) of the port uuid that it's associated with, and the qdhcp netns uses the uuid of it's network, so you should be able to use the neutron CLI to track down the correct namespace.
You should be able to find the neutron port for your tap interface with:
$ neutron port-list | grep "da4018ab-b7"
| da4018ab-b7xx-xxxx-xxxx-xxxxxxxxxxxx | | fa:16:xx:xx:xx:xx | {"subnet_id": ...
where "da4018ab-b7" was pulled out of "tapda4018ab-b7". You can then use the full port uuid:
$ neutron port-show da4018ab-b7xx-xxxx-xxxx-xxxxxxxxxxxx
The network_id in the result from port-show should let you figure out the netns (qdhcp-network_id) containing tapda4018ab-b7.
You should be able to use similar logic to track down qg interfaces (which will probably show up on bridges in the default netns), but in that case it's the device_id that owns the port that gives you the qrouter-device_id netns you want.
You can use this script. Save this as get_dhcp_namespace.sh :-
ubuntu#ubuntu$ cat get_dhcp_namespace.sh
#!/bin/bash
interface=$1
id=${interface:3}
port_id=$(neutron port-list | grep $id | awk -F'|' '{print $2}' | tr -d ' ')
net_id=$(neutron port-show $port_id | grep network_id | awk -F'|' '{print $3}' | tr -d ' ')
echo "DHCP namespace is: qdhcp-$net_id"
Run this with the tap interface provided as argument. Don't forget to source the keystonerc/openstackrc/credentials file.
ubuntu#ubuntu$ ./get_dhcp_namespace.sh tapda4018ab-b7
qdhcp-bd39f45d-b45c-4e08-ab74-85c0b1180aea
I'm not sure whether to post it here or at ServerFault.
Anyway, I'm trying to work around company's firewall to connect to some media sharing site using my phone's 3g network. I've come up with a simple ip route command which take pppd's inet address as it's parameter. But, I want to make it a little bit more automated by reading the inet address right from the script, not by passing it via command line parameter.
Here's the scenario, to make it more obvious:
The command invocation as of now: $jumpfirewall xxx.xxx.xxx.xxx
The command invocation I want: $jumpfirewall
Do you know some command or library that I can use to read it from command line?
Adapted from cyberciti:
/sbin/ifconfig ppp0 | grep 'inet addr:' | cut -d: -f2 | awk '{ print $1}'
The ifconfig ppp0 will get information for your primary PPP interface; the grep cuts it down to the line containing the IP address; the cut splits out everything after inet addr: up to bcast:, giving something like 1.2.3.4 Bcast:; and the awk call will print only the first (space-separated) field, leaving you with only the IP address.
pppd automatically calls a script in /etc/ppp/ip-up when a link is brought up. In this script, $4 is the local IP address of the PPP link. (On some distributions, /etc/ppp/ip-up is set to call the scripts in /etc/ppp/ip-up.d, with $PPP_LOCAL set to the IP address, so you can place your script there).
This way, you won't have to manually call the script - just bring up the PPP link and it'll be run automatically. There's a corresponding /etc/ppp/ip-down you can use to undo your route when the link goes down.