waht is the default address ip of nagios server - server

what is the default address IP of Nagios server?
allowed_hosts=127.0.0.1,<Nagios ip server>
Thank you in advance.

There is no default address as such,
allowed_hosts=10.0.0.1,10.0.0.2,10.0.0.3,127.0.0.1
above is the configuration which is given in the nrpe.cfg file under your nagios directory which allows you to perform remote executions by allowing the connection from the host's define above, provided the port 5666 is open.

Related

How does a client socket application identify the server application on the same host computer

I have been trying to learn socket programming in C++ and got some progress for the basics. But I understood that basics are not fundamentals.
One of those fundamentals is about the question which is stated in the title. Lets say I have two separate applications running on the same computer. One of them has a server socket and the other one has a client.
When the server gets an IP address automatically, how can client find the server? Do I have to assign an IP address that is known by the client? In that case, maybe that IP address is not available on the network.
Or can client find and connect to the server by sone kind of name or id?
Have the server bind to all interfaces and have the client lookup 'localhost' by name; it's resolved locally, (ie. no external DNS service required), to an IP address stored in a 'hosts' file, and is set by default to 127.0.0.1
Google 'hosts file'
The IP address of any server in the same host is 127.0.0.1 unless the server has bound to a specific, different IP address. As #MartinJames points out, you can use 'localhost' as the hostname for that, except on certain broken Linux distributions.

How to fix local IP in Nat Configuration on WHM/Cpanel on Centos 6 on Google Compute Engine

If you deleted a VM on Google Compute Engine on a Centos 6 Cpanel server and then create it with the same disk, you often are assigned a new local IP address even if you kept the static IP. This does not properly update in the NAT configuration on Cpanel/WHM servers.
This stops any sites from working and the only way to fix it is manually edit the http.conf file. Inside Web Host Manager you can fix the public facing IP, but there is no place to edit the local IP. Does anyone know how to edit the nat configuration on centos 6 on Google Compute Engine to fix the local IP so that all new sites created will have the correct local IP in the http.conf?
Here is a pic of the current nat configuration on my Centos 6 server.
Here is a pic showing my correct local IP in Compute Engine, you can see it does not match the one Cpanel has, which causes the http.conf file to generate new virtual hosts with the wrong IP.
Its a configuration issue within WHM/Cpanel that can not be corrected with any configuration settings in the interfaces. I contacted Cpanel Support and they provided me with a command line shell script to run from root to fix the issue. It worked flawlessly:
# /scripts/build_cpnat
This resolved the issue, but they gave this additional info if that does not solve your problem:
If this does not resolve your issue, please review our NAT
documentation and ensure that your server is configured in a supported
1:1 NAT configuration:
http://documentation.cpanel.net/display/ALD/1%3A1+NAT
The Compute Engine does not allow you to create an instance with a specific network IP address. You will have to use a combination of routes and an instance's --can-ip-forward ability to add an IP address as a static network IP address that then maps to your desired virtual machine instance.
For example, if you want to assign 10.1.1.1 specifically as a network IP address to a virtual machine instance, you can create a static route that sends traffic from 10.1.1.1 to your instance, even if the instance's network IP address assigned by Compute Engine doesn't match your desired network IP address.
Take a look at this link: https://cloud.google.com/compute/docs/instances-and-network#staticnetworkaddress
The best and the simplest solution for this is to use the WHM/Cpanel IP Migration Wizard option to change the existing Private IP with the new one and then wait for few hours to make those changes propagate and you will see the new Private IP and Public IP in sync in your WHM platform.
I had the same issue with AWS and CentOS 7 hosting latest WHM/ cPanel. each time the instance restarts then a new private/ local IP address. I deleted cpnat from /var/cpanel/.
So I disabled the NAT, then I created another eth so I can configure it with static IP which is the Public IP, then for the main account only which own the hostname and domain name for WHM I assigned it to the local IP address, but as the local IP address keep changing so I created a script fires up at the start after each boot collecting the new local IP address and assign it automatically to the main account and if there is no new local IP address then the script exit without doing anything.
here are the steps been done:
nano /etc/sysconfig/network-scripts/ifcfg-eth0:cp1
and inside that file put the following: (change IPADDR & DNS)
DEVICE="eth0:cp1"
BOOTPROTO="static"
ONBOOT="yes"
IPADDR="13.54.100.XX"
NETMASK="255.255.255.0"
DNS1="172.31.0.2"
TYPE="Ethernet"
IPV6INIT="no"
now we would like this interface to stay upon reboot and start on the reboot so run:
ifup eth0:cp1
then restart the network service by:
service network restart
now disable NAT mode by deleting the file cpnat in /var/cpanel
now check the file /var/cpanel/mainip and make sure our external ip is there 13.54.100.XX
create the following file with nano:
nano /etc/init.d/fixdhcp
add the following to the file and save it:
#!/bin/bash
# # This script assigns available DHCP IP to ACCOUNT-NAME user on Reboot or Restart, please change ACCOUNT-NAME to the main WHM domain account name
# apache service will restart when done.
/scripts/rebuildippool
export mydhcp10=$(cat /etc/ipaddrpool)
echo $mydhcp10
# Exit if no available IPs
if [ "${mydhcp10}" == "" ]; then
echo "ipaddrpool is empty" && exit 1
else
echo "ipaddrpool is not empty"
fi
/usr/local/cpanel/bin/setsiteip -u ACCOUNT-NAME $mydhcp10
chmod +x /etc/rc.d/rc.local
echo finished now restarting services
/scripts/rebuildhttpdconf
/scripts/rebuildippool
/scripts/cleandns
/scripts/fixvaliases
/scripts/modify_accounts --theme=paper_lantern --all-users
/usr/local/cpanel/scripts/updateuserdomains
service httpd restart
make the file excutable:
chmod +x /etc/init.d/fixdhcp
add it to rc.d
nano /etc/rc.local
then add it like this:
/etc/init.d/fixdhcp
save then run:
chmod +x /etc/rc.d/rc.local
If it still won't change, try this:
(i.e. when you List Accounts you see the old internal IP listed for each account)
WHM -> List Accounts expand desired account (+)
=> Change IP Address
=> select the IP address (even if it is the same external IP)
=> click change.
repeat for each affected account.
output:
The remote dns zone is not consistent with the httpd.conf.
The current ip in httpd.conf is: 10.240.0.3.
The current ip in the dns zone is: 104.154.68.68!
104.154.68.68 will be switched to the new ip as well!
The local dns zone is not consistent with the httpd.conf.
The current ip in httpd.conf is: 10.240.0.3.
The current ip in the dns zone is: 10.240.0.2!
10.240.0.2 will be switched to the new ip as well!
Warning, serious database inconsistency. httpd.conf, local dns, and remote dns all
have different ideas about what the ip address of this site really is. They will now all be changed
to the new ip: 10.240.0.2!
Changed all instances of [10.240.0.3,104.154.68.68] -> [104.154.68.68] in dcmetroc.kellen.hosting
Changed all instances of [10.240.0.3,104.154.68.68] -> [104.154.68.68] in dcmetrocollaborative.org
Updating httpd.conf....Done
System has 0 free ips.
if you're using nginx, don't forget to rebuild vhosts in ngnix plugin!
I just needed to change the local IP with the new one in:
/var/cpanel/cpnat
/etc/hosts
/etc/ips.dnsmaster

Hosting Perforce server on internet?

I am configuring my system (OSX) as a perforce server for sharing my project work with my coding partner. I want to host my server on the internet so that he will able to connect to my system. I am able to configure through this guide.Working like charm on my local host.
Maybe i am not getting something.
Please guide me to find an address or what procedure I have to do extra for making my system available to my partner .
I am very bad in UNIX terminal command
i tried these links but no answer worked for me .
Perforce with dynamic ip
Online Perforce Repositories
Some questions
Is there any need for static IP .
How i make my system available to partner over internet?
This is my p4 info.
User name: aadi
Client name: aadi-MacBook-Air
Client host: aadi-MacBook-Air.local
Client unknown.
Current directory: /Users/aadi
Client address: 127.0.0.1:50596
Server address: localhost:1666
Server root: .
Server date: 2014/11/18 01:58:14 +0530 IST
Server uptime: 00:00:10
Server version: P4D/DARWIN90U/2011.1/747877 (2013/11/21)
Server license: none
Case Handling: insensitive
I don't believe you need a static IP, so long as your partner can connect to you using your dynamic IP.
Your server has to listen on an IP address which is accessible by your partner, so "localhost:1666" will not work, because 'localhost' means to only accept connections from your own machine.
If your machine, was, say 192.168.1.101, then you'd like to see something like:
Server address: 192.168.1.101:1666
Which you should be able to accomplish by starting your server as 'p4d -p 192.168.1.101:1666'.
You can also try starting your server at 'p4d -p 1666' and see if it will listen on an address that is accessible by your partner's machine. It should, but occasionally there are problems if the IP address is not explicitly specified. If you explicitly specify your machine's IP address, and it is a dynamic IP, then you will have to stop and restart your server on the correct IP address each time your machine's IP address changes, which is rather an annoyance (and is avoided if you can in fact deploy a static IP).
All this business about static vs dynamic IP addresses should go away if your dynamic IP assignment mechanism is well-integrated with your organization's DNS infrastructure, so that your partner can use the hostname of your computer rather than the IP address.
Lastly, don't forget to check your OS X firewall: http://support.apple.com/en-us/HT201642

Stunnel - Specify Outbound IP?

Is there any way to specify a particular outbound IP address for stunnel? Right now, it's always using the main IP of the server, but I'd like it to use a specific outbound IP address.
I actually found my own answer on this one - the "local" directive.
local = host
IP of the outgoing interface is used as source for remote connections.
Use this option to bind a static local IP address, instead.

Connecting to Local Web Server when I am Outside my LAN

I have a web server running out of my home. I have assigned it an address such as 192.168.1.123 on port 80.
I understand that this is running on my local network. If I go to another computer on my network and type in the server's ip address, I can see the server.
Is there a way to access this server from outside my LAN?
Yes, you need to set your router to forward connections to port 80 to your internal IP address (192.168.1.123). Look for Port Forwarding on your router admin screen which I would imagine you access by going to http://192.168.1.1
Keep in mind that your ISP may block port 80 completely in which case you can run your web server on a different port (for example por 8180) and have your router forward connections to port 8180 to your internal IP.
To access your server from outside, you just need to point your browser to your external IP address which you can find out by going to http://www.ipchicken.com
Assuming you have a connection to the internet:
https://github.com/progrium/localtunnel
is a quick way to access your local server from the internet. There might be similar implementations in other languages/platforms. This is just the one I know about.
Remember that security issues need to be carefully considered when opening your local network to the world.
If you use a PHP Webserver you can set it this way:
php -S <YourIPAdresse>:<SomePortNumber> <StartPHPpage>
Example: „php -S 192.168.1.123:9000 index.php"