rsyslog fun - Basic Splunk Log Collection and Forwarding - Part II

By Tony Lee

Welcome to part II in our series covering how to use rsyslog to route and forward logs to Splunk. Please see Part I of the series (http://securitysynapse.blogspot.com/2019/01/rsyslog-fun-basic-splunk-log-collection-part-i.html) for the basics in opening ports, routing traffic by IP address or hostname, and monitoring files to send the data on to Splunk Indexers. As a reminder, choosing between rsyslog, syslog-ng, or other software is entirely up to the reader and may depend on their environment and approved/available software. We also realize that this is not the only option for log architecture or collection, but it may help those faced with this task—especially if rsyslog is the standard in their environment. That said, let's look at some more advanced scenarios concerning file permissions, routing logs via regex, and routing logs via ports. We will wrap up with some helpful hints on a possible method to synchronize the rsyslog and Splunk configuration files.

File Permissions

There are times where you may need to adjust the file permissions for the files that rsyslog is writing to disk. For example, if following best practice and running the Splunk Universal Forwarder as a lower privileged account, it will need access to the logs files.  Using the following rsyslogd.conf directives at the top of the configuration file will change the permissions on the directories and files created.  The following example creates directories with permissions of 755 and files with a permission of 644:

$umask 0000 $DirCreateMode 0755 $FileCreateMode 0644

Routing logs via Regex

Another more advanced rsyslog option is the ability to drop or route data at the event level via regex. For example, maybe you want to drop certain packets -- such as Cisco Teardown packets generated from ASA's. Note: this rsyslog ability is useful since we are using Splunk Universal Forwarders in our example and not Splunk Heavy Forwarders.

Or maybe you have thousands of hosts and don't want to maintain a giant list of IP addresses in an if-statement. For example, maybe you want to route thousands of Cisco Meraki host packets to a particular file via a regex pattern.

Possibly even more challenging would be devices in a particular CIDR range that end in a specific octet.

These three examples are covered in the rsyslog.conf snippet below:

#Drop Cisco ASA Teardown packets :msg, contains, ": Teardown " ~ & stop #Route Cisco Meraki hosts to specific directory if ($msg contains ' events type=') then ?ciscoMerakiFile & stop #ICS Devices 10.160.0.0/11 (last octet being .150) :fromhost-ip, regex, "10\.\\(1[6-8][0-9]\\|19[0-1]\\)\..*\.150" -?icsDevices & stop

Routing logs via Port

I know we just provided you the ability to route packets via regex, however sometimes that can be inefficient--especially at high events per second. If you are really fortunate, the source sending the data has the ability to send to a different port. Then it may be worth looking into routing data to different files based on port.  The example file below provides port 6517 and 6518 as an example.

#Dynamic template names template(name="file6517" type="string" string="/rsyslog/port6517/%FROMHOST%/%$YEAR%-%$MONTH%-%$DAY%.log") template(name="file6518" type="string" string="/rsyslog/port6518/%FROMHOST%/%$YEAR%-%$MONTH%-%$DAY%.log") #Rulesets  ruleset(name="port6517"){     action(type="omfile" dynafile="file6517") } ruleset(name="port6518"){     action(type="omfile" dynafile="file6518") } input(type="imtcp" port="6517" ruleset="port6517") input(type="imtcp" port="6518" ruleset="port6518")

Synchronizing Multiple Rsyslog Servers

Since our architecture in part I outlined using a load balancer and multiple rsyslog servers, we will eventually need a way to synchronize the configuration files across the multiple rsyslog servers.  The example below provides two bash shell scripts to perform just that task. The first one will synchronize the rsyslog configuration and the second will synchronize the Splunk configuration--both scripts restart the respective service. Note: This is not the only method available for synchronization, but it is one possible method. Remember to replace <other_server> with the actual IP or FQDN of that server.

On the rsyslog server that you make the changes on, create these two bash scripts and modify the <other_server> section. Once you make a change to the rsyslog or Splunk UF configuration, run the necessary script.

sync-rsyslog.sh

scp /etc/rsyslog.conf <other_server>:/etc/rsyslog.conf ssh <other_server> service rsyslog restart

sync-splunk.sh

scp /opt/splunkforwarder/etc/apps/SplunkUniversalForwarder/local/inputs.conf <other_server>:/opt/splunkforwarder/etc/apps/SplunkUniversalForwarder/local/inputs.conf ssh <other_server> /opt/splunkforwarder/bin/splunk restart

Conclusion

In this article, we outlined key advanced features within rsyslog that may not be immediately evident. Hopefully this article will save you some Googling time when trying to operationalize log collection and forwarding using rsyslog in your environment. After all, eventually you will probably need to deal with file permissions, routing logs via regex and/or port, and configuration synchronization. We hope you enjoyed the article and found it useful.  Feel free to post your favorite tips and tricks in the comments section below. Happy Splunking!

Basic Troubleshooting

So you did everything above and you are still not seeing data...  Walk through some of these steps:

1. Ensure all network firewalls permit the traffic
2. Ensure iptables allows traffic to the rsyslog server
3. Run tcpdump on the source to ensure it is sending data
4. Run tcpdump on the rsyslog server to ensure it is receiving data
5. Verify permissions when writing the files to disk
6. Attempt to telnet (or even web browse) to the rsyslog server port to see if anything is written to the directories

rsyslog fun - Basic Splunk Log Collection and Forwarding - Part I

By Tony Lee

We found it a bit surprising that there are so few articles on how to use an rsyslog server to forward logs to Splunk. This provided the motivation to write this article and hopefully save others some Googling. Choosing between rsyslog, syslog-ng, or other software is entirely up to the reader and may depend on their environment and approved/available software. We realize that this is not the only option for log architecture or collection, but it may help those faced with this task—especially if rsyslog is the standard in their environment.

Warnings

Before we jump in, we wanted to remind you of three potential gotchas that may thwart your success and give you a troubleshooting migraine.

1. Network firewalls – You may not own this, but make sure the network path is clear
2. iptables – Complex rule sets can throw you for a loop
3. SE Linux – Believe it or not, SE Linux when locked down can prevent the writing of the log files

If something is not working the way you expect it to work, it is most likely due to one of the three items mentioned above. It could be worth temporarily disabling them until you get everything working. Just don’t forget to go back and lock it down.

Note:  We will also be using Splunk Universal Forwarders (UF) in this article.  Universal Forwarders have very little pre-processing or filtering capabilities when compared to Heavy Forwarders.  If significant filtering is necessary, consider using a Splunk Heavy Forwarder in the same fashion as we are using the UFs below.

Architecture

Whether your Splunk instance is on-prem or it is in the cloud, you will most likely need syslog collectors and forwarders at some point. The architecture diagram below shows one potential configuration. The number of each component is configurable and dependent upon the volume of traffic.

Figure 1:  Architecture diagram illustrating traffic flow from data sources to the Index Cluster

Rsyslog configuration

Rsyslog is a flexible service, but in this case rsyslog’s primary role will be to:

• Open the sockets to accept data from the sources
• Properly route traffic to local temporary files that Splunk will forward on to the indexers

If you are fortunate enough to be able to route network traffic to different ports, you may be able to reduce the if-then logic shown below for routing the events to separate files. In this case, we were not able to open separate ports from the load balancer, thus we needed to do the routing on our end. In the next article we will cover more advanced routing to include regex and traffic coming in on different ports.

Note:  Modern rsyslog is designed to run extra config files that exist in the /etc/rsyslog.d/ directory. If that directory exists, place the following 15-splunk-rsyslog.conf file in that directory. Otherwise, the /etc/rsyslog.conf file is interpreted from top to bottom, so make a copy of your current config file (cp /etc/rsyslog.conf /etc/rsyslog.bak) and selectively add the following at the top of the new active rsyslog.conf file. This addition to the rsyslog configuration will do the following (assuming the day is 2018-06-01:

• Open TCP and UDP 514
• Write all data from 192.168.1.1 to:  /rsyslog/cisco/192.168.1.1/2018-06-01.log
• Write all data from 192.168.1.2 to:  /rsyslog/cisco/192.168.1.2/2018-06-01.log
• Write all data from 10.1.1.* to /rsyslog/pan/10.1.1.*/2018-06-01.log (where * is the last octet of the source IP
• Write all remaining data to /rsyslog/unclaimed/<host>/2018-06-01.log (where <host> is the source IP or hostname of the sender)

Note:  If the rsyslog server sees the hosts by their hostname instead of IP address, feel free to use $fromhost == '<hostname>' in the configuration file below.

/etc/rsyslog.d/15-splunk-rsyslog.conf

$ModLoad imtcp $ModLoad imudp $UDPServerRun 514 $InputTCPServerRun 514 # do this in FRONT of the local/regular rules $template ciscoFile,"/rsyslog/cisco/%fromhost%/%$YEAR%-%$MONTH%-%$DAY%.log" $template PANFile,"/rsyslog/pan/%fromhost%/%$YEAR%-%$MONTH%-%$DAY%.log" $template unclaimedFile,"/rsyslog/unclaimed/%fromhost%/%$YEAR%-%$MONTH%-%$DAY%.log" if ($fromhost-ip == '192.168.1.1' or $fromhost-ip == '192.168.1.2') then ?ciscoFile & stop if $fromhost-ip startswith '10.1.1' then ?PANFile & stop else ?unclaimedFile & stop # local/regular rules, like *.* /var/log/syslog.log

Note:  Rsyslog should create directories that don't already exist, but just in case it doesn't, you need to create the directories and make them writable.  For example:

mkdir -p /rsyslog/cisco/ mkdir -p /rsyslog/pan/ mkdir -p /rsyslog/unclaimed/

Pro tip:  After making changes to the rsyslog config file, you can verify that there are no syntax errors BEFORE you restart the rsyslog daemon.  For a simple rsyslog config validation.  Try using the following command: 

rsyslogd -N 1

If there are no errors, then you should be good to restart the rsyslog service so your changes take effect:

service rsyslog restart

Log cleanup

The rsyslog servers in our setup are not intended to store the data permanently. They are intended to act as a caching server for temporary storage before shipping the logs off to the Splunk Indexers for proper long-term storage. Since disk space is not unlimited on these caching servers we will need to implement log rotation and deletion so we do not fill up the hard disk. Our rsyslog config file already takes care of the log rotation with the template parameter specifying the name of the file as “%$YEAR%-%$MONTH%-%$DAY%.log", however, we still need to clean up the files, so they don’t sit there indefinitely. One possible solution is to use a daily cron job to clean up files in the /rsyslog/ directory that are more than x days old (where x is defined by the organization). Once you have some files in the /rsyslog/ directory, try the following command to see what would potentially be deleted. The command below lists files in the rsyslog directory that are older than two days.

find /rsyslog/ -type f -mtime +1 -exec ls -l "{}" \;

If you are happy with a two-day cache period, add it to a daily cron job (as shown below).  Otherwise feel free to play with the +1 until you are comfortable with what it will delete and use that for your cron job.

/etc/cron.daily/logdelete.sh

find /rsyslog/ -type f -mtime +1 -delete

Splunk Universal Forwarder (UF) Configuration

Splunk Forwarders are very flexible in terms of data ingest. For example, they can create listening ports, monitor directories, run scripts, etc. In this case, since rsyslog is writing the information to a directory, we will use a Splunk UF to monitor those directories and send them to the appropriate indexes and label them with the appropriate sourcetypes.  See our example configuration below.

Note:  Make sure the indexes mentioned below exist prior to trying to send data there. These will need to be created within Splunk.  Also ensure that the UF is configured to forward data to indexers (out of the scope of this write up).

/opt/splunkforwarder/etc/apps/SplunkForwarder/local/inputs.conf 

[monitor:///rsyslog/cisco/] whitelist = \.log$ host_segment=3 sourcetype = cisco:ios index = cisco [monitor:///rsyslog/pan/] whitelist = \.log$ host_segment=3 sourcetype = pan:traffic index = pan_logs [monitor:///rsyslog/unclaimed/] whitelist = \.log$ host_segment=3 sourcetype = syslog index = lastchanceindex

Pro tip:  Remember to restart the Splunk UF after modifying files.  

/opt/splunkforwarder/bin/splunk restart

Conclusion

A simple Splunk search of index=cisco, index=pan_logs, or index=lastchanceindex should be able to confirm that you are now receiving data in Splunk. Keep monitoring the lastchanceindex to move hosts to where they need to go as they come on-line. Moving the hosts is accomplished by editing the rsyslog.conf file and possibly adding another monitor stanza within the Splunk UF config. This process can be challenging to create, but once it is going, it just needs a little care from time to time to make sure that all is well.  We hope you found this article helpful.  Happy Splunking!

Basic Troubleshooting

So you did everything above and you are still not seeing data...  Walk through some of these steps:

1. Ensure all network firewalls permit the traffic
2. Ensure iptables allows traffic to the rsyslog server
3. Run tcpdump on the source to ensure it is sending data
4. Run tcpdump on the rsyslog server to ensure it is receiving data
5. Verify permissions when writing the files to disk
6. Attempt to telnet (or even web browse) to the rsyslog server port to see if anything is written to the directories

References

• https://www.rsyslog.com/storing-messages-from-a-remote-system-into-a-specific-file/ 
• https://serverfault.com/questions/400293/syslog-ip-ranges-to-specific-files-using-rsyslog  
• https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/system_administrators_guide/s1-debugging_rsyslog 

Parsing and Displaying Infoblox DHCP Data in Splunk

By Tony Lee

This article builds on our Infoblox DNS article available at:  http://securitysynapse.com/2019/01/parsing-and-displaying-infoblox-dns-in-splunk.html

If you are reading this page chances are good that you have both Splunk and Infoblox DHCP. While there is a pre-built TA (https://splunkbase.splunk.com/app/2934/) to help with the parsing, we needed some visualizations, so we wrote them and figured we would share what we created.

Figure 1:  At the time of writing this article, only a TA existed for Infoblox DHCP.

If you have this same situation, hopefully we can help you too. As a bonus, we will include the dashboard code at the end of the article.

Figure 2:  Dashboard that we include at the end of the article

Raw Log

This is what an Infoblox raw log might look like:

Sep 4 09:23:44 10.34.6.28 dhcpd[20310]: DHCPACK on 70.1.20.250 to fc:5c:fc:5f:10:85 via eth1 relay 10.120.20.66 lease-duration 600

Source:  https://docs.infoblox.com/display/NAG8/Using+a+Syslog+Server

Fields to Parse

Fortunately, our job is taken care of by the Infoblox TA (https://splunkbase.splunk.com/app/2934/)!  Just use the sourcetype of infoblox:dhcp to ensure it is properly parsed.

Search String

Now that the data is parsed, we can use the following to table the data:

index=infoblox sourcetype="infoblox:dhcp" | table _time, host, action, signature, src_category, src_hostname, src_ip, src_mac, dest_category, dest_hostname, dest_ip, relay

Combine a few panels together and we will have a dashboard similar to the one in the dashboard code section at the bottom of the article.

Conclusion

Even though we only had a Splunk TA (and not an app to go with it), we used the flexibility provided within Splunk to gain insight into Infoblox DHCP logs. We hope this article helps other save time. Feel free to leave comments in the section below. Happy Splunking!

Dashboard Code

The following dashboard assumes that the appropriate logs are being collected and sent to Splunk. Additionally, the dashboard code assumes an index of infoblox. Feel free to adjust as necessary. Splunk dashboard code provided below:

<form>
  <label>Infoblox DHCP</label>
  <description>This is a high volume data feed - Be mindful of your time range</description>
  <fieldset submitButton="true">
    <input type="time" token="time" searchWhenChanged="true">
      <label>Time Range</label>
      <default>
        <earliest>-4h@h</earliest>
        <latest>now</latest>
      </default>
    </input>
    <input type="text" token="wild" searchWhenChanged="true">
      <label>Wildcard Search</label>
      <default>*</default>
    </input>
  </fieldset>
  <row>
    <panel>
      <table>
        <title>Total DHCP Traffic by Infoblox Host</title>
        <search>
          <query>| tstats count where index=infoblox, sourcetype="infoblox:dhcp" by host</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="count">10</option>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top Action</title>
        <search>
          <query>index=infoblox sourcetype="infoblox:dhcp" $wild$ | table _time, host, action, signature, src_category, src_hostname, src_ip, src_mac, dest_category, dest_hostname, dest_ip, relay | top limit=0 action</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top signature</title>
        <search>
          <query>index=infoblox sourcetype="infoblox:dhcp" $wild$ | table _time, host, action, signature, src_category, src_hostname, src_ip, src_mac, dest_category, dest_hostname, dest_ip, relay | top limit=0 signature</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top Servicing Host</title>
        <search>
          <query>index=infoblox sourcetype="infoblox:dhcp" $wild$ | table _time, host, action, signature, src_category, src_hostname, src_ip, src_mac, dest_category, dest_hostname, dest_ip, relay | top limit=0 src_hostname</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top src_ip</title>
        <search>
          <query>index=infoblox sourcetype="infoblox:dhcp" $wild$ | table _time, host, action, signature, src_category, src_hostname, src_ip, src_mac, dest_category, dest_hostname, dest_ip, relay | top limit=0 src_ip</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top dest_ip</title>
        <search>
          <query>index=infoblox sourcetype="infoblox:dhcp" $wild$ |  table _time, host, action, signature, src_category, src_hostname, src_ip, src_mac, dest_category, dest_hostname, dest_ip, relay | top limit=0 dest_ip</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
  </row>
  <row>
    <panel>
      <table>
        <title>Raw Logs</title>
        <search>
          <query>index=infoblox sourcetype="infoblox:dhcp" $wild$ | table _time, host, action, signature, src_category, src_hostname, src_ip, src_mac, dest_category, dest_hostname, dest_ip, relay</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
          <sampleRatio>1</sampleRatio>
        </search>
        <option name="count">10</option>
        <option name="dataOverlayMode">none</option>
        <option name="drilldown">cell</option>
        <option name="percentagesRow">false</option>
        <option name="refresh.display">progressbar</option>
        <option name="rowNumbers">false</option>
        <option name="totalsRow">false</option>
        <option name="wrap">true</option>
      </table>
    </panel>
  </row>
</form>

Parsing and Displaying Infoblox DNS Data in Splunk

By Tony Lee

If you are reading this page chances are good that you have both Splunk and Infoblox DNS. While there is a pre-built TA (https://splunkbase.splunk.com/app/2934/) to help with the parsing, we needed some visualizations, so we wrote them and figured we would share what we created.

Figure 1:  At the time of writing this article, only a TA existed for Infoblox DNS.

If you have this same situation, hopefully we can help you too. As a bonus, we will include the dashboard code at the end of the article.

Figure 2:  Dashboard that we include at the end of the article

Raw Logs

DNS Query

This is what an Infoblox query might look like:

30-Apr-2013 13:35:02.187 client 10.120.20.32#42386: query: foo.com IN A + (100.90.80.102)


The fields are the following:

<dd-mmm-YYYY HH:MM:SS.uuu> <client IP>#<port> query: <query_Domain name> <class name> <type name> <- or +>[SETDC] <(name server ip)>

where
+ = recursion 
- = no recursion 
S = TSIG 
E = EDNS option set 
T = TCP query 
D = EDNS ‘DO’ flag set 
C = ‘CD’ message flag set



DNS Response

This is what an Infoblox response might look like for an A record query:

07-Apr-2013 20:16:49.083 client 10.120.20.198#57398 UDP: query: a2.foo.com IN A response: NOERROR +AED a2.foo.com. 28800 IN A 1.1.1.2;

Where the fields are the following:

<dd-mmm-YYYY HH:MM:SS.uuu> client <client ip>#port <UDP or TCP>: [view: DNS view] query: <queried domain name> <class name> <type name> response: <rcode> <flags> [<RR in text format>; [<RR in text format>;] ...]

Flags = <- or +>[ATEDVL]

where

- = recursion not available
+ = recursion available (from DNS message header)
A = authoritative answer (from DNS message header)
t = truncated response (from DNS message header)
E = EDNS OPT record present (from DNS message header)
D = DNSSEC OK (from EDNS OPT RR)
V = responding server has validated DNSSEC records
L = response contains DTC synthetic record 

Source:  https://docs.infoblox.com/display/NAG8/Capturing+DNS+Queries+and+Responses

Fields to Parse

Unfortunately, the Infoblox TA (https://splunkbase.splunk.com/app/2934/) does not seem to parse all the fields, but it might get you relatively close.  Just use the sourcetype of infoblox:dns.

Search String

Now that the data is somewhat parsed, we can use the following to table the data:

index=infoblox sourcetype="infoblox:dns" | table _time, host, message_type, record_type, query, dns_request_client_ip, dns_request_client_port,  dns_request_name_serverIP, named_message | top limit=0 dns_request_client_ip

Combine a few panels together and we will have a dashboard similar to the one in the dashboard code section at the bottom of the article.

Conclusion

Even though we only had a Splunk TA (and not an app to go with it), we used the flexibility provided within Splunk to gain insight into Infoblox DNS logs. We hope this article helps other save time. Feel free to leave comments in the section below. Happy Splunking!

Dashboard Code

The following dashboard assumes that the appropriate logs are being collected and sent to Splunk. Additionally, the dashboard code assumes an index of infoblox and a sourcetype of infoblox:dns. Feel free to adjust as necessary. Splunk dashboard code provided below:

<form>
  <label>Infoblox DNS</label>
  <description>This is a high volume data feed - Be mindful of your time range</description>
  <fieldset submitButton="true">
    <input type="time" token="time" searchWhenChanged="true">
      <label>Time Range</label>
      <default>
        <earliest>-15m</earliest>
        <latest>now</latest>
      </default>
    </input>
    <input type="text" token="wild" searchWhenChanged="true">
      <label>Wildcard Search</label>
      <default>*</default>
    </input>
  </fieldset>
  <row>
    <panel>
      <table>
        <title>Total DNS Traffic by Infoblox Host</title>
        <search>
          <query>| tstats count where index=infoblox, sourcetype="infoblox:dns" by host</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="count">10</option>
        <option name="drilldown">none</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top dns_request_client_ip</title>
        <search>
          <query>index=infoblox sourcetype="infoblox:dns" $wild$ | table _time, host, message_type, record_type, query, dns_request_client_ip, dns_request_client_port,  dns_request_name_serverIP, named_message | top limit=0 dns_request_client_ip</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top message_type</title>
        <search>
          <query>index=infoblox sourcetype="infoblox:dns" $wild$ | table _time, host, message_type, record_type, query, dns_request_client_ip, dns_request_client_port,  dns_request_name_serverIP, named_message | top limit=0 message_type</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="count">10</option>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top record_type</title>
        <search>
          <query>index=infoblox sourcetype="infoblox:dns" $wild$ | table _time, host, message_type, record_type, query, dns_request_client_ip, dns_request_client_port,  dns_request_name_serverIP, named_message | top limit=0 record_type</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top query</title>
        <search>
          <query>index=infoblox sourcetype="infoblox:dns" $wild$ | table _time, host, message_type, record_type, query, dns_request_client_ip, dns_request_client_port,  dns_request_name_serverIP, named_message | top limit=0 query</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
  </row>
  <row>
    <panel>
      <table>
        <search>
          <query>index=infoblox sourcetype="infoblox:dns" $wild$ | table _time, host, message_type, record_type, query, dns_request_client_ip, dns_request_client_port,  dns_request_name_serverIP, named_message</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
          <sampleRatio>1</sampleRatio>
        </search>
        <option name="count">10</option>
        <option name="dataOverlayMode">none</option>
        <option name="drilldown">cell</option>
        <option name="percentagesRow">false</option>
        <option name="refresh.display">progressbar</option>
        <option name="rowNumbers">false</option>
        <option name="totalsRow">false</option>
        <option name="wrap">true</option>
      </table>
    </panel>
  </row>
</form>

Parsing and Displaying Cisco ISE Data in Splunk

By Tony Lee

If you are reading this page chances are good that you have both Splunk and Cisco Identity Services Engine (ISE). Chances are also pretty good that you have seen what a challenge it can be to parse these logs and make them into a useful dashboard. Granted, there is probably one app and TA combination out of the 50+ Cisco Apps and TAs on Splunkbase that will work for you, but if you strike out there, you can always try the solution and dashboard provided in the article below.

To get started, you should at least install the TA found here to parse the fields: http://splunkbase.splunk.com/app/1915 and give your incoming Cisco ISE syslog stream a sourcetype of "cisco:ise:syslog" per the documentation here:  http://docs.splunk.com/Documentation/AddOns/released/CiscoISE/Datatypes.  If you have data flowing and the fields are parsed out, we are in business.

Now, hold on to your hats, we are about to dive into the world of Cisco ISE logs and figure out just how to create the following dashboard.

Figure 1:  A useful Cisco ISE dashboard with all necessary data.

Caveat:  This article assumes that you called your Cisco ISE index "cisco-ise".  If you did not, just change the commands and dashboard to fit your index name.

The Problem

As mentioned in the introduction, the logs are a bit messy. The upside is that they are data rich. There is so much that you can extract from the logs, but first you need to piece them back together -- literally. The logs are sent over in chunks as shown below:

2019-08-06T16:33:06+00:00 HOST CISE_Passed_Authentications 0000649495 4 3  ....

2019-08-06T16:33:06+00:00 HOST CISE_Passed_Authentications 0000649495 4 2  ....

2019-08-06T16:33:06+00:00 HOST CISE_Passed_Authentications 0000649495 4 1  ....

2019-08-06T16:33:06+00:00 HOST CISE_Passed_Authentications 0000649495 4 0  ....

Here is the kicker, those four events are related (as indicated by the first large number which we are calling an event_id and then the next two numbers, the last of which increments). When combined into one event, it contains a ton of data. So, how do we combine the events? 

The Solution

Fortunately, Splunk has a transaction function that we can use to indicate that the events are related and should be combined into one event.  But we have a problem, that field is not parsed by the Splunk TA mentioned in the introduction, so we will need to parse it.

We can parse it with the following gnarly regex:

^(?:[^ \n]* ){3}(?P<event_id>\d+)\s+

Figure 2:  event_id parsed using a Splunk field extraction

With the event_id parsed, we can now use the transaction statement to combine the four events into one event which can be seen with the following search command:

index=cisco-ise | transaction event_id

Now, let's take it a bit farther and table the most interesting fields (feel free to leave a comment if you feel that we left out an interesting field):

index=cisco-ise | transaction event_id | table _time, host, event_id, NetworkDeviceName, NAS_IP_Address, NAS_Port, Location, SelectedAuthenticationIdentityStores, SelectedAuthorizationProfiles, SSID, ISEPolicySetName, UserName, EndPointMACAddress, Calling_Station_ID, Called_Station_ID

Conclusion

We hope that this article has been helpful in understanding Cisco ISE logs and how to combine them to extract feature rich data from single events. As always, happy Splunking!

Dashboard Code

The dashboard code below assumes the index is cisco-ise and the Cisco TA is properly parsing the data. Please adjust as necessary.

<form>
  <label>Cisco ISE</label>
  <description>Populated by syslog data</description>
  <fieldset submitButton="true" autoRun="false">
    <input type="time" token="time" searchWhenChanged="true">
      <label>Time Range</label>
      <default>
        <earliest>-8h@h</earliest>
        <latest>now</latest>
      </default>
    </input>
    <input type="text" token="wild">
      <label>Wildcard</label>
      <default>*</default>
    </input>
  </fieldset>
  <row>
    <panel>
      <table>
        <title>Top Network Device Name</title>
        <search>
          <query>index=cisco-ise | transaction event_id | table _time, host, event_id, NetworkDeviceName, NAS_IP_Address, NAS_Port, Location, SelectedAuthenticationIdentityStores, SelectedAuthorizationProfiles, SSID, ISEPolicySetName, UserName, EndPointMACAddress, Calling_Station_ID, Called_Station_ID | search $wild$ | top limit=0 NetworkDeviceName</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="count">10</option>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top Location</title>
        <search>
          <query>index=cisco-ise | transaction event_id | table _time, host, event_id, NetworkDeviceName, NAS_IP_Address, NAS_Port, Location, SelectedAuthenticationIdentityStores, SelectedAuthorizationProfiles, SSID, ISEPolicySetName, UserName, EndPointMACAddress, Calling_Station_ID, Called_Station_ID | search $wild$ | top limit=0 Location</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="count">10</option>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top ISE Policy Set Name</title>
        <search>
          <query>index=cisco-ise | transaction event_id | table _time, host, event_id, NetworkDeviceName, NAS_IP_Address, NAS_Port, Location, SelectedAuthenticationIdentityStores, SelectedAuthorizationProfiles, SSID, ISEPolicySetName, UserName, EndPointMACAddress, Calling_Station_ID, Called_Station_ID | search $wild$ | top limit=0 ISEPolicySetName</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="count">10</option>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
    <panel>
      <table>
        <title>Top User Name</title>
        <search>
          <query>index=cisco-ise | transaction event_id | table _time, host, event_id, NetworkDeviceName, NAS_IP_Address, NAS_Port, Location, SelectedAuthenticationIdentityStores, SelectedAuthorizationProfiles, SSID, ISEPolicySetName, UserName, EndPointMACAddress, Calling_Station_ID, Called_Station_ID | search $wild$ | top limit=0 UserName</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
        </search>
        <option name="count">10</option>
        <option name="drilldown">cell</option>
        <option name="refresh.display">progressbar</option>
      </table>
    </panel>
  </row>
  <row>
    <panel>
      <table>
        <title>Details</title>
        <search>
          <query>index=cisco-ise | transaction event_id | table _time, host, event_id, NetworkDeviceName, NAS_IP_Address, NAS_Port, Location, SelectedAuthenticationIdentityStores, SelectedAuthorizationProfiles, SSID, ISEPolicySetName, UserName, EndPointMACAddress, Calling_Station_ID, Called_Station_ID | search $wild$</query>
          <earliest>$time.earliest$</earliest>
          <latest>$time.latest$</latest>
          <sampleRatio>1</sampleRatio>
        </search>
        <option name="count">10</option>
        <option name="dataOverlayMode">none</option>
        <option name="drilldown">cell</option>
        <option name="percentagesRow">false</option>
        <option name="refresh.display">progressbar</option>
        <option name="rowNumbers">false</option>
        <option name="totalsRow">false</option>
        <option name="wrap">true</option>
      </table>
    </panel>
  </row>
</form>