Nagios Support Forum

Posted: **Wed Sep 15, 2021 12:51 pm**

Hello,

We have an implementation of Nagios in our network, and the server has 2 NICs, one to be able to communicate with all customer's devices and another one for management from our network. We want to be able to send traps to Nagios from both networks, but for some reason, Nagios only sees traps originating from our customer's network.
Is there a way to intruct SNMPTT to listen on all IPs?

Thanks in advance

Posted: **Thu Sep 16, 2021 1:53 pm**

What is the output of these commands?

Code: Select all

uname -a
cat /etc/*release
netstat -anop | grep 162
ps aux | grep trapd

By default, snmptrapd listens for incoming SNMP TRAP and INFORM packets on UDP port 162 on all IPv4 interfaces

Taken from here:

https://net-snmp.sourceforge.io/docs/man/snmptrapd.html

Posted: **Thu Sep 16, 2021 2:22 pm**

Hello ssax,

I thought the same, that it only listens in port 162, but I can't explain why I see traps arriving only from 1 network and not from the other (btw, with tcpdump, I do see the traps on the 2nd interface).

Regarding the outputs:
uname -a
Linux cupnagapp00 3.10.0-1127.13.1.el7.x86_64 #1 SMP Fri Jun 12 14:34:17 EDT 2020 x86_64 x86_64 x86_64 GNU/Linux

cat /etc/*release
NAME="Red Hat Enterprise Linux Server"
VERSION="7.8 (Maipo)"
ID="rhel"
ID_LIKE="fedora"
VARIANT="Server"
VARIANT_ID="server"
VERSION_ID="7.8"
PRETTY_NAME="Red Hat Enterprise Linux"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:7.8:GA:server"
HOME_URL="https://www.redhat.com/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"

REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 7"
REDHAT_BUGZILLA_PRODUCT_VERSION=7.8
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="7.8"
Red Hat Enterprise Linux Server release 7.8 (Maipo)
Red Hat Enterprise Linux Server release 7.8 (Maipo)

netstat -anop | grep 162
tcp 0 0 10.224.40.60:51162 10.224.40.61:8086 ESTABLISHED 1159/nagflux keepalive (3.77/0/0)
udp 0 0 0.0.0.0:162 0.0.0.0:* 1158/snmptrapd off (0.00/0/0)
unix 2 [ ACC ] STREAM LISTENING 16202 838/VGAuthService /var/run/vmware/guestServicePipe
unix 2 [ ] DGRAM 16234 1185/rhnsd
unix 2 [ ] DGRAM 16220 1156/xinetd
unix 2 [ ] DGRAM 21621 861/chronyd

ps aux | grep trapd
root 1158 0.0 0.2 269736 41456 ? Ss Feb14 246:21 /usr/sbin/snmptrapd -Lsd -f

Posted: **Thu Sep 16, 2021 5:41 pm**

Edit this file:

Code: Select all

/etc/sysconfig/snmptrapd

Add this to it (setting the IP addresses to what yours are):

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OPTIONS="-Lsd -f udp:127.0.0.1:162 udp:192.168.X.X:162 udp:192.168.Y.Y:162"

Then restart snmptrapd:

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systemctl restart snmptrapd

Posted: **Fri Sep 17, 2021 3:17 pm**

Locking thread, ticket received, we will continue support through the ticket.

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