1. Install Snmp In Centos 7 Iptables Save
2. Start Iptables Centos 7
3. Centos 7 Iptables Config
4. Stop Iptables In Centos 7
5. Install Snmp In Centos 7 Iptables
6. Centos 7 Iptables Disable

This guide describe howto install and do a basic configure of SNMP on a RedHat Enterprise Linux or CentOS. Probably it will work on many other *nix systems.

1. Install Iptables on CentOS/RHEL 7. Now install iptables service using yum package manager using the following command. Sudo yum install iptables-services After installing enable iptables service and start using below commands. Sudo systemctl enable iptables sudo systemctl start iptables Now check the iptables service status using below command.
2. Installing Cacti Web-based Network Monitoring on RHEL/CentOS 7. # yum -y install php php-cli php-mysql net-snmp-utils rrdtool php-snmp gcc net-snmp-devel autoconf.

I'm having a problem here, I've added to my IPtables rules this:

but when I scan with nmap or any other tool it says this:

also when I am doing:

Also:

Any idea what's going on? There is no UDP in closed/open state. what do I have to do?

Ladadadada

1 Answer

By default, snmpd listens to UDP port 161 on all interfaces. If you want to use TCP, you will have to configure that in your snmpd.conf or in /etc/default/snmpd.

The fact that nmap sees port 161 as 'closed' rather than 'filtered' means that it got a RST packet in return when it tried to contact TCP port 161 rather than getting nothing back. This means that your IPTables rules are working fine.

Install Snmp In Centos 7 Iptables Save

LadadadadaLadadadada

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I installed snmp on CentOS 7.2, like so:

I made a backup of my snmpd.conf file:

then I cleared the text, with this:

and added to the snmpd.conf, the following:

rocommunity '#random$' monitoring_server_ip

The monitoring_server_ip is the server that that is allowed to connect to this snmpd server.

Restarted snmpd

When I run snmpwalk on my CentOS 7.2 server

I then get:

Timeout: No Response from localhost

Which is accurate, because there is only one IP-adres that can do that, as we have defined before.

ps shows that snmp is running

/usr/sbin/snmpd -LS0-6d -f

This is my first time playing with snmp and any help is greatly appreciated!

output of iptables -L -n | grep udp shows this:

All of the destination was too 0.0.0.0/0?

Netstat shows the following port:

also this:

Also, in my firewall, added that only one IP-adres can access my snmp server:

Start Iptables Centos 7

blade19899blade19899

1 Answer

The com2sec security model is not mandatory anymore.

In snmpd.conf it should be enough to do:

where 2.2.2.2 is the monitoring IP address allowed to connect.I often prefer to assign a single IP, than giving access to a whole /24. So this configuration means the SNMP service will answer requests from the 2.2.2.2 address.

You might also have to comment the line that restricts the snmpd daemon to the localhost for security reasons.

After changing the configuration file, do:

To confirm if it is listening locally:

And from the allowed network/IP, for walking the entire MIB tree. Assuming 2.2.2.1 is the machine being monitored:

or for asking for the sysUpTime OID:

snmpget has to have the 0 for the specific object instance/index.

Centos 7 Iptables Config

P.S: 2.2.2.2 is the monitoring server, and 2.2.2.1 is the snmpd server/host to be monitored.

Rui F Ribeiro

Stop Iptables In Centos 7

Rui F Ribeiro

Install Snmp In Centos 7 Iptables

Centos 7 Iptables Disable

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