Getting Data In

UDP/514 Port not receiving Data from All Sources

deltamph
Explorer

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?

Tags (1)

mlf
Path Finder

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

0 Karma

yannK
Splunk Employee
Splunk Employee

Please check 3 things (if you are on linux)

0 Karma

EdBruce
Explorer

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.

0 Karma

yannK
Splunk Employee
Splunk Employee

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-...

0 Karma

deltamph
Explorer
  • 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
0 Karma

deltamph
Explorer

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.

0 Karma

MHibbin
Influencer

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

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