SNMP: No response from localhost

daithi_dearg · 07-06-2016, 10:43 AM

Hello,

I'm setting up Redhat machines for SNMP Alerts on Whatsup. I have already a CENTOS machine set up on the same alert and I see no issues.

I can do a SNMPwalk with the GUI and I can navigate from Oject ID "1." and see data whereas on the Redhat machines I don't see this. It goes nowhere.

I see this on 2 Redhat boxes.

So now I'm trying to prove is it a local problem or is it with the communication from this Whatsup server to the box.

/etc/snmp/snmpd.conf matches on both boxes.

I was trying running the following but it has problems even on the box that has SNMP working:

Code:

[user@server2 ~]$ sudo snmpwalk -v 1 -c GETS3RV3R1NFO! localhost
Timeout: No Response from localhost

Do I need different syntax?

The ports appear to be open and this matches the working machine:

Code:

[user@server1~]$  sudo netstat -lnp|grep 16
udp        0      0 0.0.0.0:161             0.0.0.0:*                           43818/snmpd

Also can connect to this port:

Code:

[user@server2 ~]$ sudo nc -v -u -w 3 sonarqube 161
Ncat: Version 6.40 ( http://nmap.org/ncat )
Ncat: Connected to 192.168.212.131:161.

Iptables doesn't appear to be an issue:

Code:

[user@server1 ~]$ systemctl status iptables.service
● iptables.service
   Loaded: not-found (Reason: No such file or directory)
   Active: inactive (dead)

Also /etc/selinux/config has SELINUX set to disabled.

If I had syntax to check if this was working locally I'd appreciate it.

Thanks,
David

TB0ne · 07-06-2016, 10:53 AM

Instead of localhost (which probably resolves to 127.0.0.1...the LOOPBACK address), try putting your FQDN or IP address in of the local machine.

daithi_dearg · 07-06-2016, 10:58 AM

I'm afraid the FQDN and the IP address get the same result even on the machine that is working for SNMP

TB0ne · 07-06-2016, 11:13 AM

The syntax is correct, and it working on my system here. Are you positive that you have SNMPv1 enabled on your system, and not 2c or 3? What is the result of "service snmpd status"?

daithi_dearg · 07-06-2016, 12:02 PM

The machine this is not running on is Redhat 7.2. Are you running this on Redhat?

Even on the machine that SNMP does work on I get the same results for that snmpwalk command. I can run snmpwalk on the whatsup serverand navigate down through the Object IDs.

On the Redhat server that isn't working I have the following in /etc/snmp/snmpd.conf:

Code:

group   notConfigGroup v1           notConfigUser
group   notConfigGroup v2c           notConfigUser

That's correct isn't it?

SNMP service is running:

Code:

[user@server1 ~]$ systemctl status snmpd.service
● snmpd.service - Simple Network Management Protocol (SNMP) Daemon.
   Loaded: loaded (/usr/lib/systemd/system/snmpd.service; disabled; vendor preset: disabled)
   Active: active (running) since Wed 2016-07-06 21:29:19 IST; 3h 6min ago
 Main PID: 43818 (snmpd)
   CGroup: /system.slice/snmpd.service
           └─43818 /usr/sbin/snmpd -LS0-6d -f

Jul 06 21:29:18 server1 systemd[1]: Starting Simple Network Management Protocol (SNMP) Daemon....
Jul 06 21:29:19 server1 snmpd[43818]: NET-SNMP version 5.7.2
Jul 06 21:29:19 server1 systemd[1]: Started Simple Network Management Protocol (SNMP) Daemon..

TB0ne · 07-07-2016, 07:08 AM

Quote:

Originally Posted by daithi_dearg

The machine this is not running on is Redhat 7.2. Are you running this on Redhat?
Even on the machine that SNMP does work on I get the same results for that snmpwalk command. I can run snmpwalk on the whatsup serverand navigate down through the Object IDs. On the Redhat server that isn't working I have the following in /etc/snmp/snmpd.conf:

Code:

group   notConfigGroup v1           notConfigUser
group   notConfigGroup v2c           notConfigUser

That's correct isn't it?

Doesn't look like it. Have you contacted RHEL support, or checked their knowledegbase on how to configure SNMPD??
https://access.redhat.com/documentat...MP-Configuring

It's typically something like

Code:

rocommunity public 127.0.0.1
rwcommunity mysecret 127.0.0.1

...where 'ro' is the read-only (snmpget/snmpwalk), and 'rw' is read/write (suitable for use with snmpset).

Quote:

SNMP service is running:

Code:

[user@server1 ~]$ systemctl status snmpd.service
● snmpd.service - Simple Network Management Protocol (SNMP) Daemon.
   Loaded: loaded (/usr/lib/systemd/system/snmpd.service; disabled; vendor preset: disabled)
   Active: active (running) since Wed 2016-07-06 21:29:19 IST; 3h 6min ago
 Main PID: 43818 (snmpd)
   CGroup: /system.slice/snmpd.service
           └─43818 /usr/sbin/snmpd -LS0-6d -f

Jul 06 21:29:18 server1 systemd[1]: Starting Simple Network Management Protocol (SNMP) Daemon....
Jul 06 21:29:19 server1 snmpd[43818]: NET-SNMP version 5.7.2
Jul 06 21:29:19 server1 systemd[1]: Started Simple Network Management Protocol (SNMP) Daemon..

Do the logs tell you anything??

daithi_dearg · 07-07-2016, 08:16 AM

Unfortunately we don't pay for support where we are unfortunately.

According to that guide I have the correct setup but I continue to see the same issues.

I suppose if I don't have a Redhat machine working it's an issue on this OS.

I do have the setting:

Code:

rocommunity password a.b.c.d

I changed the logging in /etc/sysconfig/snmpd to:

Code:

# OPTIONS="-LS0-7d"

from a 6 to a 7 but I'm not seeing increased logging:

Code:

  Active: active (running) since Thu 2016-07-07 20:43:25 IST; 9s ago
 Main PID: 3868 (snmpd)
   Memory: 4.3M
   CGroup: /system.slice/snmpd.service
           └─3868 /usr/sbin/snmpd -LS0-6d -f

I'm not sure what else I can try here.

TB0ne · 07-07-2016, 08:48 AM

Quote:

Originally Posted by daithi_dearg

Unfortunately we don't pay for support where we are unfortunately.

Sorry, but if you're using RHEL, you need to PAY FOR IT, no matter where you are. If this is a new system, stop exactly where you are, and load CentOS instead. It's identical to RHEL, but FREE. Without RHEL support, you WILL NOT get updates/patches/bugfixes/security-fixes. The only thing you're going to accomplish without support, is to put a production system is that will very quickly become unstable, insecure, and you will have a MUCH harder time installing any new software in the future. In short, you're only going to give yourself headaches.

Quote:

According to that guide I have the correct setup but I continue to see the same issues. I suppose if I don't have a Redhat machine working it's an issue on this OS. I do have the setting:

Code:

rocommunity password a.b.c.d

I changed the logging in /etc/sysconfig/snmpd to:

Code:

# OPTIONS="-LS0-7d"

from a 6 to a 7 but I'm not seeing increased logging:

Code:

  Active: active (running) since Thu 2016-07-07 20:43:25 IST; 9s ago
 Main PID: 3868 (snmpd)
   Memory: 4.3M
   CGroup: /system.slice/snmpd.service
           └─3868 /usr/sbin/snmpd -LS0-6d -f

I'm not sure what else I can try here.

Back up your existing SNMPD.conf file, and take out everything except for the ro/rw lines, and see what you get.

daithi_dearg · 07-07-2016, 09:09 AM

Maybe I didn't explain myself fully.

These Redhat boxes are fully licensed and we have a fully paid Redhat subscription but it just doesn't include anything besides licensing support.

I'll do those steps you suggested and come back to you.