Detect and restrict unwanted traffic

Friday, January 29, 2016 9:26:31 AM

NOTE: This article is refering to older version of Quotas (< 5.2.8).

Here we will learn how to use Quota rule to detect and restrict unwanted traffic. Let's assume we are on expensive satellite connection and we don't want any hungry application to ruin our tariff.

Go to Filters tab and create filter named "Any process <-> Internet". Add filter function "Remote host is on Internet" so all internet traffic will be captured by this filter. The Per-Type attribute is set to Per-Process - the filter together with it's rules will be applied to each process separately:

/img/docs/quota/create-filter.png

Save the filter:

/img/docs/quota/filter-view-1.png

Then click to Add Rule to add the quota. Change the Rule Type to Quota:

/img/docs/quota/add-quota.png

In the rule editor, click to Actions and check the "Enable all rules in the same filter" checkbox. Later we will add Limit rule to our filter and this option ensures the rule will be started when the quota overflows. Also check "Show alert window on overflow" - NetLimiter will show notification window on the quota overflow:

/img/docs/quota/quota-actions.png

Save the quota rule.

Now click Add Rule again. Set the rule type to Limit and uncheck the "Enabled" checkbox. The limit rule will be started when the quota overflows and thanks the "Per-Process" filter type, each process will be limited separately:

/img/docs/quota/add-limit.png

Now the quota and limit rule are ready:

/img/docs/quota/filter-view-2.png

Let's test it. Open Internet Explorer and start downloading a file. Shortly NetLimiter will open alert window informing us that the quota overflowed:

/img/docs/quota/quota-overflow-1.png

Now the limit rule is started and the process transfer rate is restricted. The alert window shows process Id and process Name which is the "Internet Explorer". We can take immediately one of the predefined actions:

  • Kill the connections belonging to the process so that the traffic is terminated immediately.
  • Ignore the quota: the quota will be ignored in case of this process and hence the process will continue transferring data unaffected.
  • Reset the quota: the measurement will start from beginning. The process will continue transferring the data unaffected until new quota overflow.

For now, no action is taken. Instead of that, we start Media Player and listen to some online radio. NetLimiter will detect the traffic and the quota for Media Player overflows shortly. Now we can see two process in the quota status window:

/img/docs/quota/quota-overflow-2.png

We can use the pagination control to move to the second process indicated. As expected, the second process causing the quota overflow is the Media Player:

/img/docs/quota/quota-overflow-3.png

In case the quota status window is closed, we can reopen it by right clicking the quota rule and choosing "Show Quota Status":

/img/docs/quota/open-status-window.png