Add FAQ entry for HCC public subnets.

content/FAQ/_index.md

@@ -13,7 +13,8 @@ weight = "95"
 - [I am trying to run a job but nothing happens?](#i-am-trying-to-run-a-job-but-nothing-happens)
 - [I keep getting the error "slurmstepd: error: Exceeded step memory limit at some point." What does this mean and how do I fix it?](#i-keep-getting-the-error-slurmstepd-error-exceeded-step-memory-limit-at-some-point-what-does-this-mean-and-how-do-i-fix-it)
 - [I want to talk to a human about my problem. Can I do that?](#i-want-to-talk-to-a-human-about-my-problem-can-i-do-that)
-- [My submitted job takes long time waiting in the queue or it is not running?](#my-submitted-job-taked-long-time-waiting-in-the-queue-or-it-is-not-running)
+- [My submitted job takes long time waiting in the queue or it is not running?](#my-submitted-job-takes-long-time-waiting-in-the-queue-or-it-is-not-running)
+- [What IP's do I use to allow connections to/from HCC resources?](#what-ip-s-do-i-use-to-allow-connections-to-from-hcc-resources)
 
 ---
 
@@ -178,4 +179,15 @@ session at [hcc-support@unl.edu](mailto:hcc-support@unl.edu), or you can drop on
 If your submitted jobs are taking long time waiting in the queue, that usually means your account is over-utilizing and your fairshare score is low, this might be due submitting big number of jobs over the past period of time; and/or the amount of resources (memory, time) you requested for your job is big.
 For additional details on how to monitor usage on jobs, check out the documentation on [Monitoring queued Jobs]({{< relref "monitoring_jobs" >}}).
 
+#### What IP's do I use to allow connections to/from HCC resources?
+Under normal circumstances no special network permissions are needed to access HCC resources. Occasionally, it may be necessary to whitelist the public IP
+addresses HCC utilizes. Most often this is needed to allow incoming connections for an external-to-HCC license server, but may also be required
+if your local network blocks outgoing connections. To allow HCC IP's, add the following ranges to the whitelist:
+{{< highlight batch >}}
+129.93.175.0/26
+129.93.227.64/26
+129.93.241.16/28
+{{< /highlight >}}
 
+If you are unsure on how to do this, contact your local IT support staff for assistance.
+For additional questions or issues with this, please [Contact Us](https://hcc.unl.edu/contact-us).