Getting Data In

Do Splunk inputs dedicated to universal forwarders need reverse DNS configured?

vptltd
Engager

We have around 230 PCs servers spelunking to a single splunk server across a firewall.

Many of these clients are not logging data and show connection and timeout errors in splunkd log etc. After some research I have seen suggestions that incorrectly configured reverse DNS may be a cause.

Simple question is do the splunk inputs dedicated to universal forwarders need configuration regarding DNS? I thought that the hostname was provided by the splunk forwarder config files rather than DNS.

Am I confusing other inputs with which need this?
Any advice gratefully received.

Tags (2)
1 Solution

vptltd
Engager

Managed to resolve this with the help of tech support and solution is below in case others find it useful.

Reverse DNS lookups were indeed the issue. When creating the splunk forwarder input, the default "connection_host" (inputs.conf) is to use reverse dns. In our case no dns/access via firewall was possible to multiple timouts/net traffic generated which was stopping other clients connecting reliably.

Edited the input to "connection_host" to "none", restarted splunk and all was well with no further connection timeouts in splunkd.log etc.

View solution in original post

vptltd
Engager

Managed to resolve this with the help of tech support and solution is below in case others find it useful.

Reverse DNS lookups were indeed the issue. When creating the splunk forwarder input, the default "connection_host" (inputs.conf) is to use reverse dns. In our case no dns/access via firewall was possible to multiple timouts/net traffic generated which was stopping other clients connecting reliably.

Edited the input to "connection_host" to "none", restarted splunk and all was well with no further connection timeouts in splunkd.log etc.

Get Updates on the Splunk Community!

[Puzzles] Solve, Learn, Repeat: Dynamic formatting from XML events

This challenge was first posted on Slack #puzzles channelFor a previous puzzle, I needed a set of fixed-length ...

Enter the Agentic Era with Splunk AI Assistant for SPL 1.4

  🚀 Your data just got a serious AI upgrade — are you ready? Say hello to the Agentic Era with the ...

Stronger Security with Federated Search for S3, GCP SQL & Australian Threat ...

Splunk Lantern is a Splunk customer success center that provides advice from Splunk experts on valuable data ...