<div dir="ltr"><div>Hi All<br><br></div>I am using bird-1.4.5-1.el6, we are getting alerted for TCP md5 authentication failures for almost on all the server's BGP peering with switches. Error we are seeing as mentioned below.<br><p>Jul 17 17:15:29 <a href="http://lca1-s1-csw02.nw.linkedin.com">lca1-s1-csw02.nw.linkedin.com</a> 2017 Jul 17 17:15:29 UTC: %NETSTACK-3-TCP_MD5_AUTH_FAILURE: netstack <span class="error">[3617]</span> MD5_DIGEST_INVALID:Dropping packets from src:x.x.x.x.34987,dst:y.y.y.yy.179</p>

<p>Jul 17 07:24:28 <a href="http://lca1-e1-csw01-lo0.nw.linkedin.com">lca1-e1-csw01-lo0.nw.linkedin.com</a> 2017 Jul 17 07:24:28 UTC: %NETSTACK-3-TCP_MD5_AUTH_FAILURE: netstack <span class="error">[3640]</span> MD5_DIGEST_INVALID:Dropping packets from src:yyyy.yyyy.yyyy.35088,dst:xxxx.xxxx.xxx.179</p>

<p><a href="http://lca1-s1-csw01.nw.linkedin.com">lca1-s1-csw01.nw.linkedin.com</a> 2017 Jul 17 05:01:25 UTC: %NETSTACK-3-TCP_MD5_AUTH_FAILURE: netstack <span class="error">[3617]</span> MD5_DIGEST_INVALID:Dropping packets from src:x.x.x.xx.55220,dst:1y.y.y.yy.179</p><p><br></p><p>we have raised a Case with Cisco and they are saying possible cause would be "<span style="color:rgb(31,73,125);font-family:Calibri,sans-serif;font-size:14.6667px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);display:inline;float:none"><span class="gmail-Apple-converted-space"> </span><span style="color:rgb(0,0,0)">If received packet has got modified in transit, so hash computed at origin is not matching at the destination". <br></span></span></p><p><span style="color:rgb(0,0,0)"><span style="font-family:Calibri,sans-serif;font-size:14.6667px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);display:inline;float:none"><br></span></span></p><p><span style="color:rgb(0,0,0)"><span style="font-family:Calibri,sans-serif;font-size:14.6667px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);display:inline;float:none">Does anyone have seen this type of error before?  Is bird causing something to corrupt the packet?  Any solution / way to check and confirm everything fine at bird is  appreciated.</span></span></p><p><span style="color:rgb(0,0,0)"><span style="font-family:Calibri,sans-serif;font-size:14.6667px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);display:inline;float:none"><br></span></span></p><p><span style="color:rgb(0,0,0)"><span style="font-family:Calibri,sans-serif;font-size:14.6667px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);display:inline;float:none">Regards</span></span></p><p><span style="color:rgb(31,73,125);font-family:Calibri,sans-serif;font-size:14.6667px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);display:inline;float:none"><span style="color:rgb(0,0,0)">Harish Shetty</span><br></span></p><p><span style="color:rgb(31,73,125);font-family:Calibri,sans-serif;font-size:14.6667px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);display:inline;float:none"><br></span></p><p><span style="color:rgb(31,73,125);font-family:Calibri,sans-serif;font-size:14.6667px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);display:inline;float:none"><br></span></p></div>