Install and Configure SNMP on the Asus RT-AC66U Router

ASUS_RT-AC66U_newsOk first off let me start by saying that this is probably the coolest piece of home computing hardware that I have ever laid my hands on. Yes the setup was easy, and yes the thing is rock solid, and yes wireless range is awesome. But for approx $200 USD you really should not expect anything less.  I’m not going to go into its specs or features, as I’ll leave that to the professionals. Read up on it here.

Anyway out of the box it supported telnet, but I wanted ssh, so I dropped the default firmware and went with Asuswrt-Merlin. It was at this point I started to explore the Busybox OS and decided I wanted to monitor the device via my HomeLab Zenoss install.

However, much to my chagrin net-snmp was not installed out of the box.

So how do you install it you ask? Would you believe via a package manager?

First, you need to find the package name

#ipkg list | grep snmp

Then install the snmp package

#ipkg install net-snmp

Then configure it to start at boot time. net-snmp yes

In order to configure it, you are going to have to search for the snmp.conf

#find / -name snmpd.conf

I found two files and one of them clearly states that you should not edit it directly. The other one does not so this is the one that I modified to include my custom rocommunity. See below.

rocommunity  lab

Now I just need to figure out how to allow port 161 udp/tcp on my local LAN segment and I am in business. However, I will probably tackle that tomorrow.


Additional Info (2016)

Note, you can restart snmp as shown below.


admin@RT-AC66U:/tmp/home/root# net-snmp
killall: dm2_transmission-daemon: no process killed
killall: asus_lighttpd: no process killed
killall: dm2_snarfmaster: no process killed
killall: dm2_nzbget: no process killed
killall: dm2_amuled: no process killed
iptables: No chain/target/match by that name
iptables: Bad rule (does a matching rule exist in that chain?)


admin@RT-AC66U:/tmp/home/root# net-snmp yes
The field(Enabled) was set “yes” already.
Restarting the package…


2016 Update – Configuring SNMP via the WebUI

Figured that I would add an update to this post as it seems that there are plenty of folks who are looking to setup SNMP on their Asus routers. Note that SNMP can now be configured directly from the WebUI.

In the left pane, click on “Advanced Setting”. Then click on the “SNMP” tab. See example below. Note that the webui does not seem to pick up your configuration if you have configured it via the cli. I have not tested to see if the WebUI overwrites the CLI configuration or if it creates another configuration file.


Additional Resources

Fatmin: How to Add a Static Route on the Asus RT-AC66U

Fatmin: Install and Configure SNMP on the Asus RT-AC66U

Enabling SNMP in ESXi 4.1 using the Remote CLI


Based on the fact that ESX 4.1 is the last major release of ESX, I decided that I would make myself familiar with managing ESXi hosts.  Since I monitor all my hosts via Zenoss, I figured that I needed to get snmp up and running first.

So I first when out and installed the remote cli for ESX on my ubuntu desktop.  The rcli can be downloaded here. The remote cli allows you to run command administrative commands against ESX/ESXi systems. Its availbile for Windows or Linux.

Configuring on ESXi 4.1, Licensed

First configure your community string, target, and port:

vicfg-snmp –server <ESXi_ip> -c <communityname> -p 161 -t <destination_host>@161/<community name>

Then enable it using the command below:

vicfg-snmp –server <ESXi_ip> -E

Next verify your settings:

vicfg-snmp –server <ESXi_ip> -s

Now test your settings:

vicfg-snmp –server <ESXi_ip> -T

These settings are written out to /etc/vmware/snmp.xml. Sample file below.

/etc/vmware # cat snmp.xml
<targets>10.1.xx.xx@161 public</targets>

Configuring on ESXi 4.0, Free/Foundation

I had a couple of ESXi 4.0 free hosts to configure, but my attempts to configure them using the cli failed as the snmp settings via cli were read only. So the first thing that you need to do is enable the unsupported console. Instructions can be found here.

Once you are able to ssh to the ESXi box, you need to edit the following file by hand, /etc/vmware/snmp.xml. Use the sample file above as a template and modify your ip, port, and string as needed. I use vi to edit mine.

Then run the command below restart

You can then verify your settings using the remote cli by running the command below against your esxi box.

vicfg-snmp –server <ESXi_ip> -T

ESX Post Install – Enable NTP and SNMP

FirewallThis post is the first in what I suspect will be a semi-long list of post-install hints and tips as I go through and start rebuilding my cluster as Vsphere 4. Hopefully I will learn a lot along the way… like for example the fact the ntp and snmp traffic is not allowed by default by the ESX Firewall.

But before we go there we first need to make sure that our services are starting at boot.

>chkconfig ntp on, … do the same for snmp

Then lets fix the firewall. First lets fix ntp.

esxcfg-firewall -e ntpClient

Then lets verify that all is well with…

esxcfg-firewall -q ntpClient

This command returns…

Service ntpClient is enabled

Ok now lets fix snmp using the same commands above, but specific for snmp.

esxcfg-firewall -e snmp and esxcfg-firewall -q snmpd.

While you are at it add the following to you snmp.conf

dlmod SNMPESX /usr/lib/vmware/snmp/

Then restart snmp and ntp and you should be good.