Why isn't syslog data being indexed by Splunk configured to listen through UDP port?

[SalimRahmani]

Hello,

I've written a script in python that forwards Syslog to a remote server. For testing, it's just my second laptop. On this second one, I've checked using tftp and wireshark tools to see whether the syslog is received or not. It is! However, when I configure splunk to receive the syslog data by listening to a UDP port (default 514 or sometimes i changed it) I have nothing indexed though I receive no error.

I'd be grateful if you could help me!
Thanks in advance,

[grijhwani · Accepted solution]

The big problem with UDP is that it is fire and forget. There is no guarantee of delivery. Do you even know, for sure, that the syslog traffic is reaching the indexer and isn't blocked by firewall or something?

[Ayn]

Check local firewall rules. Wireshark/tcpdump will pick up this traffic even if it is then blocked by iptables, so it will look fine even though the traffic is not making it to Splunk.

[SalimRahmani]

Thank you so much Ayn! It was the firewall actually.

[SalimRahmani]

Hi guys,

Thank you so much for your answers! Actually, it was my firewall that Splunk couldn't index. So I created a new rule in the inboud firewall. Now it works perfectly!

Thanks again!