Common Wi-Fi Issues Caused by Wired Problems

Recently, Rowell joined NetAlly on a webinar to discuss common Wi-Fi issues caused by wired problems.

Often times, Wi-Fi gets blamed for nearly every networking problem. But after doing some troubleshooting the issue comes from the wired infrastructure.

We take a look at four common issues that look like Wi-Fi issues but are really wired problems.

You can also catch the webinar on YouTube.

Switch Ports

Common problems occur during switch provisioning. Your installer connects the AP to the switch but it’s not working properly. The main IT contact is not there on-site and users are beginning to get frustrated.

It’s possible the AP was plugged into the wrong port but sometimes it’s not easy to trace the cable. You want to know if the switch port is configured properly. Maybe it’s an access port when it should be a trunk port.

We’ve used the NetAlly EtherScope nXG to leverage CDP or LLDP to find out which switch and port it’s connected to. It’s part of the Auto Test feature and there are various settings you can enable for a Quick Test.

Identifying connected port


Here, we have a Wi-Fi test showing DHCP was not successful. As part of troubleshooting, you might not know if the wireless device is able to see the SSID, associate, pass authentication, get DHCP, etc.

DHCP failure

Which step in getting connected are we having issues? In this scenario, our EtherScope associates to an AP on channel 48 but the test fails at DHCP.

Based on that information, we now know how we should troubleshoot further. Is there a missing VLAN somewhere? Is the AP using the right native VLAN? Or maybe we have the incorrect VLAN.

In the field, techs can leverage tools like the EtherScope nXG to troubleshoot quickly and upload the results to Link-Live. That’s when a network engineer or administrator can look at the details remotely without having to be onsite.

Sometimes we don’t have the luxury of getting on a plane to travel onsite to troubleshoot an issue. It takes too long and it can be costly.

When we plug the EtherScope nXG into the port where the access point is plugged in, we cannot see any traffic on VLAN 120, the VLAN the SSID is configured to use.

Could that be the problem, the SSID configuration or the switch port configuration? Now we’re getting somewhere.

Identifying traffic on VLAN 120


You may have received a ticket about the LED on an AP not being on. Or maybe the AP is in a reboot cycle. It could be connected but not serving any clients.

This could possibly be a PoE problem. Either the AP is not receiving PoE because the switch doesn’t support it or PoE is disabled at the switch port.

A quick test can verify PoE.

Detecting PoE

You may be getting ready to upgrade APs but did you consider the PoE requirements at the switch level? We’ve ran into situations where the PoE budget on the switch has been depleted.

On the EtherScope nXG, we can set a test for a specific powered device class. The EtherScope will try and negotiate the power requirement.

If you’ve worked with a Cisco 1562E then you may know that you’re going to need a lot of power coming from the switch port.

Here’s how to use a quick test to verify if a Class 4 powered device will work on a switch and on the right I’m testing UPOE. You can see the switch port gave me 25.50 watts. You may be able see if you’re reaching the max PoE budget of the switch.

Link Negotiation

We’ve had users experience slow Wi-Fi and after troubleshooting everything, including the RF, but wasn’t able to identify a problem. If we had started at the physical layer first, we may have seen the issue right away.

We can’t how many times we’ve come across bad cables where the APs negotiate at poor speeds. Sometimes even at half duplex!

Link Negotiation

That’s when you need to test the cable and re-terminate or run a new cable. Troubleshoot at the physical layer first. It may save you some time.


While the NetAlly EtherScope nXG was used as the primary tool in this post, it is possible to identify these problems using alternate methods. Our primary goal is to identify and resolve these issues quickly. Most of the time, the easiest and most reliable tool you can acquire can help save the day.

To find out more about the NetAlly EtherScope nXG, please contact us today.

4 thoughts on “Common Wi-Fi Issues Caused by Wired Problems”

  1. I’ve seen every one of these in the field at one time or another. The two most common ones I’ve seen Wi-Fi get blamed for when it’s not actually a Wi-Fi problem is violation of the 20:1 Access-Distribution oversubscription ratio and / or violation of the 4:1 Distribution-Core ratio, creating a Distribution System bottleneck for all those CAPWAP / GRE or DTLS / IPsec tunneled frames to the MC(s) / WLC(s) *AND* seemingly everything in the Cloud now and insufficient Internet bandwidth for the site and / or Enterprise. This used to be something we saw all the time in the Hospitality vertical (Wi-Fi might be right, but insufficient Internet bandwidth equals “the Wi-Fi sucks at this hotel.” Now, though, we’re starting to see it in many other verticals because of so much being moved to the Cloud but very few shops having the instrumentation or traffic studies to know when to increase the size of their Internet in a business justifiable way.

    1. Rowell Dionicio says:

      Thanks for your input, Michael! Really detailed. I’m curious, how do you end up solving your ratio issues?

  2. Anusha says:

    Internet Issues- ARP issues , DNS not resolved issues

    1. Rowell Dionicio says:

      Thanks, Anusha. Those are some common issues we see too. How do you handle the ARP issues?

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

[gravityforms id=16 title=false description=false]
<script type="text/javascript">var gform;gform||(document.addEventListener("gform_main_scripts_loaded",function(){gform.scriptsLoaded=!0}),window.addEventListener("DOMContentLoaded",function(){gform.domLoaded=!0}),gform={domLoaded:!1,scriptsLoaded:!1,initializeOnLoaded:function(o){gform.domLoaded&&gform.scriptsLoaded?o():!gform.domLoaded&&gform.scriptsLoaded?window.addEventListener("DOMContentLoaded",o):document.addEventListener("gform_main_scripts_loaded",o)},hooks:{action:{},filter:{}},addAction:function(o,n,r,t){gform.addHook("action",o,n,r,t)},addFilter:function(o,n,r,t){gform.addHook("filter",o,n,r,t)},doAction:function(o){gform.doHook("action",o,arguments)},applyFilters:function(o){return gform.doHook("filter",o,arguments)},removeAction:function(o,n){gform.removeHook("action",o,n)},removeFilter:function(o,n,r){gform.removeHook("filter",o,n,r)},addHook:function(o,n,r,t,i){null==gform.hooks[o][n]&&(gform.hooks[o][n]=[]);var e=gform.hooks[o][n];null==i&&(i=n+"_"+e.length),gform.hooks[o][n].push({tag:i,callable:r,priority:t=null==t?10:t})},doHook:function(n,o,r){var t;if(r=Array.prototype.slice.call(r,1),null!=gform.hooks[n][o]&&((o=gform.hooks[n][o]).sort(function(o,n){return o.priority-n.priority}),o.forEach(function(o){"function"!=typeof(t=o.callable)&&(t=window[t]),"action"==n?t.apply(null,r):r[0]=t.apply(null,r)})),"filter"==n)return r[0]},removeHook:function(o,n,t,i){var r;null!=gform.hooks[o][n]&&(r=(r=gform.hooks[o][n]).filter(function(o,n,r){return!!(null!=i&&i!=o.tag||null!=t&&t!=o.priority)}),gform.hooks[o][n]=r)}});</script> <div class='gf_browser_unknown gform_wrapper gravity-theme' id='gform_wrapper_16' ><form method='post' enctype='multipart/form-data' id='gform_16' action='/common-wi-fi-issues-caused-by-wired-problems/' > <div class='gform_body gform-body'><div id='gform_fields_16' class='gform_fields top_label form_sublabel_below description_below'><fieldset id="field_16_1" class="gfield gfield_contains_required field_sublabel_below field_description_below gfield_visibility_visible" data-js-reload="field_16_1"><legend class='gfield_label gfield_label_before_complex' >Name<span class="gfield_required"><span class="gfield_required gfield_required_text">(Required)</span></span></legend><div class='ginput_complex ginput_container no_prefix has_first_name no_middle_name no_last_name no_suffix gf_name_has_1 ginput_container_name' id='input_16_1'> <span id='input_16_1_3_container' class='name_first' > <input type='text' name='input_1.3' id='input_16_1_3' value='' aria-required='true' placeholder='First Name' /> <label for='input_16_1_3' >First</label> </span> </div></fieldset><div id="field_16_2" class="gfield gfield--width-full gfield_contains_required field_sublabel_below field_description_below gfield_visibility_visible" data-js-reload="field_16_2"><label class='gfield_label' for='input_16_2' >Email<span class="gfield_required"><span class="gfield_required gfield_required_text">(Required)</span></span></label><div class='ginput_container ginput_container_email'> <input name='input_2' id='input_16_2' type='text' value='' class='large' placeholder='Business email address' aria-required="true" aria-invalid="false" /> </div></div><fieldset id="field_16_3" class="gfield gfield_contains_required field_sublabel_below field_description_below gfield_visibility_visible" data-js-reload="field_16_3"><legend class='gfield_label gfield_label_before_complex' >Consent<span class="gfield_required"><span class="gfield_required gfield_required_text">(Required)</span></span></legend><div class='ginput_container ginput_container_checkbox'><div class='gfield_checkbox' id='input_16_3'><div class='gchoice gchoice_16_3_1'> <input class='gfield-choice-input' name='input_3.1' type='checkbox' value='I consent to the processing and sharing with partners of the personal data that I provide Packet 6 for this activity in accordance with and as described in the &lt;a href=&quot;https://packet6.com/privacy-policy&quot; target=&quot;_new&quot;&gt;Privacy Policy&lt;/a&gt;' id='choice_16_3_1' /> <label for='choice_16_3_1' id='label_16_3_1'>I consent to the processing and sharing with partners of the personal data that I provide Packet 6 for this activity in accordance with and as described in the <a href="https://packet6.com/privacy-policy" target="_new">Privacy Policy</a></label> </div></div></div></fieldset><div id="field_16_4" class="gfield gform_validation_container field_sublabel_below field_description_below gfield_visibility_visible" data-js-reload="field_16_4"><label class='gfield_label' for='input_16_4' >Comments</label><div class='ginput_container'><input name='input_4' id='input_16_4' type='text' value='' /></div><div class='gfield_description' id='gfield_description_16_4'>This field is for validation purposes and should be left unchanged.</div></div></div></div> <div class='gform_footer top_label'> <input type='submit' id='gform_submit_button_16' class='gform_button button' value='Get the report' onclick='if(window["gf_submitting_16"]){return false;} window["gf_submitting_16"]=true; ' onkeypress='if( event.keyCode == 13 ){ if(window["gf_submitting_16"]){return false;} window["gf_submitting_16"]=true; jQuery("#gform_16").trigger("submit",[true]); }' /> <input type='hidden' class='gform_hidden' name='is_submit_16' value='1' /> <input type='hidden' class='gform_hidden' name='gform_submit' value='16' /> <input type='hidden' class='gform_hidden' name='gform_unique_id' value='' /> <input type='hidden' class='gform_hidden' name='state_16' value='WyJbXSIsImY4MGVlNTA5MGVjMWYzYzU5NzUyOGFhOWE3ZGFiMzRlIl0=' /> <input type='hidden' class='gform_hidden' name='gform_target_page_number_16' id='gform_target_page_number_16' value='0' /> <input type='hidden' class='gform_hidden' name='gform_source_page_number_16' id='gform_source_page_number_16' value='1' /> <input type='hidden' name='gform_field_values' value='' /> </div> <p style="display: none !important;"><label>&#916;<textarea name="ak_hp_textarea" cols="45" rows="8" maxlength="100"></textarea></label><input type="hidden" id="ak_js_2" name="ak_js" value="222"/><script>document.getElementById( "ak_js_2" ).setAttribute( "value", ( new Date() ).getTime() );</script></p></form> </div>