I can't find anything that helps with this issue even if the answer may be very simple.
I'm trying to get squid to redirect traffic through a 3g dongle, therefore I need to table the IP and change it in the squid.conf every time it changes.
I'm using this code here on "/etc/ppp/ip-up.local" so it's launched every time a new IP connects (or reconnects) to the machine.
#!/bin/bash
if [[ "$PPP_IFACE" == "ppp0" ]] ; then
TABLE=uplink2
/bin/sed -i "s&\(tcp_outgoing_address\).*\(very1\)&\1 $PPP_LOCAL \2&" /etc/squid/squid.conf
fi
##generate ip subnet for route
baseip=`echo "$PPP_LOCAL" | cut -d"." -f1-3`
/usr/sbin/ip route add "$baseip".0/24 dev "$PPP_IFACE" src "$PPP_LOCAL" table "$TABLE"
/usr/sbin/ip route add default via "$PPP_REMOTE" table "$TABLE"
/usr/sbin/ip rule add from "$PPP_LOCAL" table "$TABLE"
/usr/sbin/squid/ -k reconfigure
/usr/bin/systemctl squid restart
exit 0
The problem is that baseip=echo "$PPP_LOCAL" | cut -d"." -f1-3 cannot use $PPP_LOCAL
I tried to add echo $PPP_LOCAL >> file.txt but it just adds an empty line.
It's awkward to me that sed instead accesses the variable and modify correctly the squid.conf file with the new address
How can I fix this??
I also have a "sub-question", I'm a complete newbie just starting to learn and I'm not sure whether or not I should add an ip-down code to remove the table rules
Thanks everyone for the help
Related
I would like to trigger a service when a change of an ip address on a specific interface occurs. Is there a target for this or some other method I am not aware of to achieve this using systemd on Linux (Kernel 3.19)?
The service would be used to send a SIGNAL to a defined process. The Linux is running on an embedded system.
Thanks!
Because you use Systemd you might already use systemd-networkd for managing your devices instead of relying on 3rd party code.
You could use the structured journal output to get the last 2 ADDRESS field of the current BOOD_ID.(sadly, there is no notification mechanism for address changes in systemd-networkd):
→ sudo journalctl -F ADDRESS -u systemd-networkd -n 2
192.168.178.29
So, if there is only one line output, there was no address change.
There is an solution in other question of StackOverflow. Just here:
Detecting a change of IP address in Linux
I like this code, it's easy, you onli need a cron job with frecuency as you need (I made a little change):
#!/bin/bash
OLD_IP=`cat ip.txt`
NEW_IP=`/sbin/ifconfig | awk -F "[: ]+'{ print $4}'`
if [ $NEW_IP != OLD_IP ]; then
YOU_COMMAND <commands>
echo $NEW_IP > ip.txt
fi
exit 0
I am trying to get this function to file .bashrc
This is my function :
function my_ip() {
echo "internal or external?"
read -r choise
if [ "$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$4}'|cut -d '"' -f4;
fi
}
My goal is that the function will quickly give me my IP by choosing internal or external
if I want to automatically displays the network card ("without the need to ask Which network card do you use(The computer automatically detects which network card the user uses and will put the name as a variable at the right commend for internal IP , how can I get him to identify what card the user use(WLAN0 WLAN1 etc.) ?
A system can have more than one IP address. Which one of them is the one you are looking for? You did not specify that.
There are multiple questions related to finding IP addresses with bash:
Find internal IP address
The accepted answer uses a deprecated option for hostname; the second answer is the more correct one IMHO.
In bash, is there a way to find the IP address for all interfaces?
Find IP address for my system
Bash script to find all IP addresses
If none of those float your boat, consider closing this question and posting a new one with more precise phrasing what you are looking for.
My isp provides dynamic ip addresses.I have forwarded my port to an raspberry pi and accessing it through ssh and also using it as web server.but the problem is that ip changes every 3-4 days is there any way or script so that i can be informed or updated with new ip address.
Thank You.
You can write a script like:
============
#!/bin/bash
OUT=$(wget http://checkip.dyndns.org/ -O - -o /dev/null | cut -d: -f 2 | cut -d\< -f 1)
echo $OUT > /root/ipfile
============
Set a cron to execute this every 3h or something and configure your mta to send the file /root/ipfile to your email address ( that too you can use a cron ). mutt can be a useful tool to attach the file and do the email delivery.
I have a fog server set up in work, every now and then our useless internet fails and I have to reset the dnsmasq to get it working again, (don't have a dhcp server set up and can't modify the hubs settings so won't be doing this). Whenever I try sudo dnsmasq restart, I get the message:
junk found in command line.
First of all, can some please explain to me in simple terms what this actually means? As I am no Linux expert and nobody seems to have a simple explanation as to what this is...
Secondly, I have always used the command posted on another the fog forum to correct this error.
sudo /etc/init.d/dnsmasq restart
This always worked perfectly however now when I try to run this command I get the message:
command not found`.
Edit your /etc/init.d/dnsmasq
My linux distribution is Debian 9 (stretch)
Change this line :
ROOT_DS="/usr/share/dns/root.ds"
if [ -f $ROOT_DS ]; then
DNSMASQ_OPTS="$DNSMASQ_OPTS `sed -e s/". IN DS "/--trust-anchor=.,/ -e s/" "/,/g $ROOT_DS | tr '\n' ' '`"
fi
To :
ROOT_DS="/usr/share/dns/root.ds"
if [ -f $ROOT_DS ]; then
DNSMASQ_OPTS="$DNSMASQ_OPTS `sed -e s/".*IN[[:space:]]DS[[:space:]]"/--trust-anchor=.,/ -e s/"[[:space:]]"/,/g $ROOT_DS | tr '\n' ' '`"
fi
This problem occurs due to updating the dns-root-data package, more precisely in the file /usr/share/dns/root.ds.
The structure of this file was changed, the fields were separated only by spaces, now they were changed by tabs (\t)
sudo service dnsmasq start
That worked for me
Try sudo restart dnsmasq. The /etc/init.d/ directory is the location of System V init scripts. If dnsmasq is not there, it's probably been converted to use upstart and its configuration is in /etc/init/
I need a Bash (or a plain shell) script to put in a cronjob that every minute checks if the Internet is up.
This is how I did it:
#! /bin/sh
host1=google.com
host2=wikipedia.org
curr_date=`date +"%Y%m%d%H%M"`
echo -n "${curr_date};"
((ping -w5 -c3 $host1 || ping -w5 -c3 $host2) > /dev/null 2>&1) &&
echo "up" || (echo "down" && exit 1)
How would you do it? Which hosts would you ping?
Clarifications:
By "internet is up", I mean my internet connection.
By "up", I mean to have usable connection (doesn't really matter if we are talking about the DNS being down or the connection is really really slow [mind the -w for timeout]). That is also why I didn't include any IP but only hosts.
Should I also ping Stack Overflow? I mean, if I can't access Google, Wikipedia or Stack Overflow, I don't want Internet :p
That one seems like a good solution. Just add a few more hosts, and maybe some pure IP hosts so you don't rely on DNS functioning (which in itself depends on your definition of "up").
Thanks for your code, it works great, I've left only one line actually:
((ping -w5 -c3 8.8.8.8 || ping -w5 -c3 4.2.2.1) > /dev/null 2>&1) && echo "up" || (echo "down" && exit 1)
What portion of Internet connectivity are you looking to check? DHCP? DNS? Physically being plugged into a jack? Kernel recognizing the presence of the NIC?
You can manually query your ISP's DNS server(s) by using the host(1) command. This is generally a good indication of whether your router has lost its connection to the ISP.
You can query what interfaces your kernel has by using netstat(8) or ifconfig(8).
You can get detailed statistics about the interface using ifstat.