topic Re: UDP/514 Port not receiving Data from All Sources in Getting Data In

UDP/514 Port not receiving Data from All Sources

deltamph — Wed, 10 Oct 2012 13:39:29 GMT

I have a UDP/514 Port setup in data inputs. i have a number of machines sending syslog data to this port however only certain applications show up in splunk. the rest never get there. Is there any kind of log that would show what is happening? is splunk dropping the data. I see on wireshark that the data leaves the sending machine and i am aware that UDP does not ensure delivery but i would expect at least one or two packets to make it?

Any ideas why this would be?

Re: UDP/514 Port not receiving Data from All Sources

MHibbin — Wed, 10 Oct 2012 13:49:27 GMT

Have you run a tcpdump/wireshark on the machine running Splunk?

Have you confirmed the end-to-end connectivity from each host? - it is common that a firewall would block some connections but not others depending on legacy rules

Re: UDP/514 Port not receiving Data from All Sources

deltamph — Wed, 10 Oct 2012 14:06:33 GMT

i have run wireshark on the sending computer and verified the packets at least leave the computer.

i will see about running a Dump on the splunk machine to see if i receive it.

Re: UDP/514 Port not receiving Data from All Sources

yannK — Wed, 10 Oct 2012 14:20:17 GMT

Please check 3 things (if you are on linux)

verify that splunk run as root, otherwise he will not be able to open port under 1024 (reserved to root only)
use netstat with options to verify that splunk is the process listening to UDP 514
if your events are coming from another subnet, see http://splunk-base.splunk.com/answers/12876/splunk-running-on-my-linux-server-is-only-showing-me-events-from-my-local-subnet-what-is-going-on

Re: UDP/514 Port not receiving Data from All Sources

deltamph — Wed, 10 Oct 2012 14:27:53 GMT

Splunk is running as root. we have other apps that work send to udp/514 and they are showing up in splunk.
Splunk is listening on 514 as some apps show up.
I will check to see about the local subnet issue. Thanks

Re: UDP/514 Port not receiving Data from All Sources

mlf — Tue, 25 Jun 2013 16:30:07 GMT

Make sure your syslog daemon (or equivalent) it not listing on udp:514 as well.

Re: UDP/514 Port not receiving Data from All Sources

yannK — Fri, 08 Nov 2013 00:55:18 GMT

can it be this problem with data spoofed from a different subnet ?
http://answers.splunk.com/answers/12876/splunk-running-on-my-linux-server-is-only-showing-me-events-from-my-local-subnet-what-is-going-on

Re: UDP/514 Port not receiving Data from All Sources

EdBruce — Wed, 18 May 2016 17:03:44 GMT

I have the same problem. Firewall on Splunk server is disabled, changed rp_filter to 0, I see the packets from both Cisco firewalls in tcpdump, but only see events from one firewall being indexed.