What does one do when they get the error below while trying to see the shared NFS directory with the help of the showmount command:-
[[email protected] ~]# showmount -e server_address
clnt_create: RPC: Port mapper failure - Unable to receive: errno 113 (No route to host)
The root cause of getting this error above is your firewall. Make sure that you've enabled the 2049 port for NFS and port 111 for Portmap, or if you can stop iptables that will also help.
/etc/init.d/iptables stop.
Now again try to check the shared drive using the address below:-
[[email protected] ~]# showmount -e server_address
For ex-
[[email protected] ~]# showmount -e 10.10.50.124
Export list for 10.10.50.124:
/usr/local/src 10.10.50.0/24
That's it.
qmHandle is a utility for managing the Qmail and mail queue operations. By default, it is not installed with Qmail configuration but you can install it to easily manage Qmail and perform the following operations:-
- Checking the number of emails in Qmail.
- Reading the messages in the mail queue.
- Removing messages from the queue using filters like header, subject, ip, etc.
... and many more things can be done with qmHandle!
To install qmHandle use the steps below:-
step 1: Login onto the mail server and download the qmHandle package using the link below:-
cd /usr/local/src/
wget http://kaz.dl.sourceforge.net/project/qmhandle/qmhandle-1.3/qmhandle-1.3.2/qmhandle-1.3.2.tar.gz
step 2: Extract the qmHandle binary using the command below:-
tar -xzf qmhandle-1.3.2.tar.gz
step 3: Move the Qmail binary from its directory to the Qmail binary directory where you've installed it on the server. For example if you installed it under /var/qmail/ follow the steps below:-
cd qmhandle-*/
mv qmHandle /var/qmail/bin/
step 4: Then you can use it as below:-
/var/qmail/bin/qmHandle -s (To check the emails in the queue)
Total messages: 0
Messages with local recipients: 0
Messages with remote recipients: 0
Messages with bounces: 0
Messages in preprocess: 0
To use more options with qmHandle, run the command below and you'll get all the options that you can use with qmHandle.
/var/qmail/bin/qmHandle
That's all.
We've seen that due to old WordPress versions on websites and sometimes due to DDOS attacks on xmlrpc.php, the website and server may become unstable and the traffic to the website may increase as well.
To fix this issue we have a solution which will nullify and completely remove such a DDOS attack.
Method 1: Redirect the attack to a bogus IP so that the request becomes null. Set this redirect in the .htaccess file and that's all :-
RewriteRule ^xmlrpc\.php$ “http\:\/\/0\.0\.0\.0\/” [R=301,L]
Method 2: Disable the access for xmlrpc.php using the .htaccess file with the Allow and Deny rules as below :-
<Files xmlrpc.php>
Order allow,deny
Deny from all
</Files>
Both of the above methods are very effective and will surely work in this situation. That's all!
