Check and verify that DNS is not being blocked upstream by a firewall. Behavior is weird, the server can get out to the internet, access to the servers IP address is available, but can’t ping domains that are locally hosted. Are also unable to ping the domains from the internet in.
To resolve the issue either disable the DNS firewall rules, or better yet add some rules to allow access to the cPanel server.
Freeradius by default uses ports 1812 and 1813, udp traffic. To allow through firewalld run the following commands and restart the service.
sudo firewall-cmd --port-add=1812/udp --permanent
sudo firewall-cmd --port-add=1812/udp --permanent
sudo systemctl restart firewalld
The commands are for CentOS, but should work on Fedora and RedHat.
If semanage is not installed refer to here.
You would typically use this along with the systems firewall to allow a port through. Guide for firewalld and iptables. If you change it in the firewall and fail to add/edit it in semanage you can potentially get weird behavior like sshd not wanting to start after changing the port.
Add port
semanage port -a -t ssh_port_t -p tcp 2222
The above command allows the sshd service to start, using port 2222.
List allowed ports
semanage port -l
You can use grep to filter the results
Example:
[admin@localhost ~]# semanage port -l | grep ssh ssh_port_t tcp 2222, 22 [admin@localhost ~]#
Delete port
semanage port -d -p tcp 2222
Other examples
Allow SNMP
semanage port -a -t snmp_port_t -p udp 161
Firewalld
sudo firewall-cmd --zone=public --permanent --add-port=1714-1764/tcp sudo firewall-cmd --zone=public --permanent --add-port=1714-1764/udp sudo systemctl restart firewalld.service
UFW firewall
sudo ufw allow 1714:1764/udp sudo ufw allow 1714:1764/tcp sudo ufw reload
More information https://community.kde.org/KDEConnect
Install SNMP.
yum install net-snmp net-snmp-utils
Configure the SNMP V3 user by running the following command and then following the prompts it gives you.
net-snmp-create-v3-user
Example: The username is “snmpadmin” and the password is”r123456″
[root@localhost ~]# net-snmp-create-v3-user Enter a SNMPv3 user name to create: snmpadmin Enter authentication pass-phrase: r123456 Enter encryption pass-phrase: [press return to reuse the authentication pass-phrase] adding the following line to /var/lib/net-snmp/snmpd.conf: createUser snmpadmin MD5 "r123456" DES adding the following line to /etc/snmp/snmpd.conf: rwuser snmpadmin [root@localhost ~]#
Change the syslocation and syscontact in the /etc/snmp/snmpd.conf file.
vi /etc/snmp/snmpd.conf
Start snmpd service
service snmpd start
Configure snmp to start on system boot.
chkconfig snmpd on
Test and make sure snmp is working
replace “password” and “username” with the ones you setup when you created the SNMP V3 user.
snmpwalk -v3 -a MD5 -A password -x DES -X password -l authPriv -u privuser localhost
If you receive something like “snmpwalk: Timeout” then something is not working correctly. Check to make sure the service is started, and make sure that your firewall is not blocking SNMP.
If you are running a firewall, run the following commands to allow it through.
firewall-cmd --zone=public --add-port=161/udp --permanent semanage port -a -t snmp_port_t -p udp 161 firewall-cmd --reload
On iptables you should be able to do
iptables -A INPUT -p tcp -m state --state NEW -m tcp --dport 161 -j ACCEPT
or add it to /etc/sysconfig/iptables and then restart iptables
Note: If you have SELinux enabled you’ll need to allow the port in semanage.
Basic syntax
firewall-cmd --zone=public --add-port=(port number)/(protocal)
So the command to allow port 80 through the firewall would be
firewall-cmd --zone=public --add-port=http/tcp or firewall-cmd --zone=public --add-port=80/tcp
The above command only works for the running instance of firewalld. If you want to add the port permanetely you need to run the above command and then run it again with “–permanent” added to the end of the command.
example:
firewall-cmd --zone=public --add-port=http/tcp firewall-cmd --zone=public --add-port=http/tcp --permanent
Open up Windows Firewall with Advanced Security.
You can do this by going to
Control Panel –> System and security –> Windows Firewall –> Advanced settings
Or hit the Windows key and type in firewall and hit enter
Select Inbound rules and then add a New Rule. On the New Inbound Rule Wizard select Custom for the type of rule and hit next. Allow All programs and then hit next again. Select ICMPv4 as the Protocol type and if you want you can specify the ICMP types by clicking on the Customize button. Finish running through the wizard give it a name etc. and click Finish when your done.