<html xmlns="http://www.w3.org/TR/REC-html40" xmlns:st="" xmlns:Z="urn:schemas-microsoft-com:" xmlns:spsl="http://microsoft.com/webservices/SharePointPortalServer/PublishedLinksService" xmlns:pptsl="http://schemas.microsoft.com/sharepoint/soap/SlideLibrary/" xmlns:ex12m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:ex12t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:spwp="http://microsoft.com/sharepoint/webpartpages" xmlns:mrels="http://schemas.openxmlformats.org/package/2006/relationships" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns:mver="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:mdssi="http://schemas.openxmlformats.org/package/2006/digital-signature" xmlns:dssi="http://schemas.microsoft.com/office/2006/digsig" xmlns:dsss="http://schemas.microsoft.com/office/2006/digsig-setup" xmlns:wf="http://schemas.microsoft.com/sharepoint/soap/workflow/" xmlns:udcp2p="http://schemas.microsoft.com/data/udc/parttopart" xmlns:udcxf="http://schemas.microsoft.com/data/udc/xmlfile" xmlns:udcs="http://schemas.microsoft.com/data/udc/soap" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:sps="http://schemas.microsoft.com/sharepoint/soap/" xmlns:sp="http://schemas.microsoft.com/sharepoint/" xmlns:ec="http://www.w3.org/2001/04/xmlenc#" xmlns:sub="http://schemas.microsoft.com/sharepoint/soap/2002/1/alerts/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:udc="http://schemas.microsoft.com/data/udc" xmlns:dsp="http://schemas.microsoft.com/sharepoint/dsp" xmlns:ds="http://www.w3.org/2000/09/xmldsig#" xmlns:dir="http://schemas.microsoft.com/sharepoint/soap/directory/" xmlns:ois="http://schemas.microsoft.com/sharepoint/soap/ois/" xmlns:ppda="http://www.passport.com/NameSpace.xsd" xmlns:x2="http://schemas.microsoft.com/office/excel/2003/xml" xmlns:mt="http://schemas.microsoft.com/sharepoint/soap/meetings/" xmlns:Repl="http://schemas.microsoft.com/repl/" xmlns:D="DAV:" xmlns:rtc="http://microsoft.com/officenet/conferencing" xmlns:q="http://schemas.xmlsoap.org/soap/envelope/" xmlns:html="http://www.w3.org/TR/REC-html40" xmlns:oa="urn:schemas-microsoft-com:office:activation" xmlns:odc="urn:schemas-microsoft-com:office:odc" xmlns:c="urn:schemas-microsoft-com:office:component:spreadsheet" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns:b="urn:schemas-microsoft-com:office:publisher" xmlns:z="#RowsetSchema" xmlns:rs="urn:schemas-microsoft-com:rowset" xmlns:s="uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882" xmlns:dt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882" xmlns:a="urn:schemas-microsoft-com:office:access" xmlns:p="urn:schemas-microsoft-com:office:powerpoint" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:v="urn:schemas-microsoft-com:vml">
<head>
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:"Tw Cen MT";
panose-1:2 11 6 2 2 1 4 2 6 3;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body vlink="purple" link="blue" lang="EN-US">
<div class="Section1">
<p class="MsoNormal">Hi, I’m using gpxe 1.0.0+ and it’s not
working in certain cases where it tries to ARP for the default gateway I configured
for it via a script. After a lot of head scratching I finalized sniffed
the traffic using Wireshark to see exactly what it was doing when it didn’t
work versus what it was doing when it did work. I’ve included
the two ARP requests below. It works when I plug the computer that
I’m using gpxe for into a little Netgear switch which then connects to a
Cisco 2960. When I plug it directly into the 2960 it doesn’t
work. The ARP request packets from gpxe look slightly different
between these two scenarios (top one works):<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New"">No.
Time
Source
Destination
Protocol Info<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> 1
0.000000
Dell_35:67:ed
Broadcast
ARP Who has 172.28.113.1? Tell
172.28.113.203<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""><o:p> </o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New"">Frame 1 (60 bytes on wire, 60 bytes captured)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Arrival Time: May 17, 2010
11:13:17.736812000<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Time delta from previous
captured frame: 0.000000000 seconds]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Time delta from previous
displayed frame: 0.000000000 seconds]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Time since reference or first
frame: 0.000000000 seconds]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Frame Number: 1<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Frame Length: 60 bytes<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Capture Length: 60 bytes<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Frame is marked: False]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Protocols in frame: eth:arp]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Coloring Rule Name: ARP]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Coloring Rule String: arp]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New"">Ethernet II, Src: Dell_35:67:ed (00:24:e8:35:67:ed),
Dst: Broadcast (ff:ff:ff:ff:ff:ff)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Destination: Broadcast
(ff:ff:ff:ff:ff:ff)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Source: Dell_35:67:ed
(00:24:e8:35:67:ed)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Type: ARP (0x0806)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Trailer:
000000000000000000000000000000000000<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New"">Address Resolution Protocol (request)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Hardware type: Ethernet (0x0001)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Protocol type: IP (0x0800)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Hardware size: 6<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Protocol size: 4<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Opcode: request (0x0001)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Sender MAC address: Dell_35:67:ed
(00:24:e8:35:67:ed)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Sender IP address: 172.28.113.203
(172.28.113.203)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Target MAC address:
00:00:00_00:00:00 (00:00:00:00:00:00)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Target IP address: 172.28.113.1
(172.28.113.1)<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This one doesn’t work:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New"">No.
Time
Source
Destination
Protocol Info<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> 1
0.000000 Dell_35:67:ed
Broadcast
ARP Who has 172.28.113.1? Tell
172.28.113.203<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""><o:p> </o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New"">Frame 1 (60 bytes on wire, 60 bytes captured)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Arrival Time: May 17, 2010
11:25:38.286573000<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Time delta from previous
captured frame: 0.000000000 seconds]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Time delta from previous
displayed frame: 0.000000000 seconds]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Time since reference or first
frame: 0.000000000 seconds]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Frame Number: 1<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Frame Length: 60 bytes<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Capture Length: 60 bytes<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Frame is marked: False]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Protocols in frame: eth:arp]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Coloring Rule Name: ARP]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> [Coloring Rule String: arp]<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New"">Ethernet II, Src: Dell_35:67:ed (00:24:e8:35:67:ed),
Dst: Broadcast (ff:ff:ff:ff:ff:ff)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Destination: Broadcast
(ff:ff:ff:ff:ff:ff)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Address:
Broadcast (ff:ff:ff:ff:ff:ff)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> .... ...1
.... .... .... .... = IG bit: Group address (multicast/broadcast)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> .... ..1.
.... .... .... .... = LG bit: Locally administered address (this is NOT the
factory default)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Source: Dell_35:67:ed
(00:24:e8:35:67:ed)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Address:
Dell_35:67:ed (00:24:e8:35:67:ed)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> .... ...0
.... .... .... .... = IG bit: Individual address (unicast)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> .... ..0.
.... .... .... .... = LG bit: Globally unique address (factory default)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Type: ARP (0x0806)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Trailer:
000000000000000000000000000000000000 <o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New"">Address Resolution Protocol (request)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Hardware type: Ethernet (0x0001)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Protocol type: IP (0x0800)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Hardware size: 6<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Protocol size: 4<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Opcode: request (0x0001)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Sender MAC address: Dell_35:67:ed
(00:24:e8:35:67:ed)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Sender IP address: 172.28.113.203
(172.28.113.203)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Target MAC address:
00:00:00_00:00:00 (00:00:00:00:00:00)<o:p></o:p></span></p>
<p style="text-autospace:none" class="MsoNormal"><span style="font-size:10.0pt;
font-family:"Courier New""> Target IP address: 172.28.113.1
(172.28.113.1)<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Note that the different between the two is in the Ethernet
II field with the IG/LG bits. Does this make sense to anyone?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Ben<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto" class="MsoNormal"><i><span style="font-size:12.0pt;font-family:"Tw Cen MT","sans-serif";color:green">Benjamin
Derstine</span></i><span style="font-size:12.0pt;font-family:"Tw Cen MT","sans-serif""><o:p></o:p></span></p>
<p style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto" class="MsoNormal"><span style="font-size:12.0pt;font-family:"Tw Cen MT","sans-serif"">Systems
Administrator<o:p></o:p></span></p>
<p style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto" class="MsoNormal"><span style="font-size:12.0pt;font-family:"Tw Cen MT","sans-serif"">Pennsylvania
State University <br>
Division of Student Affairs <br>
Information Technology <br>
222 Boucke Building <br>
University Park, PA 16802 <o:p></o:p></span></p>
<p style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto" class="MsoNormal"><span style="font-size:12.0pt;font-family:"Tw Cen MT","sans-serif"">Phone:
814-863-9844<o:p></o:p></span></p>
<p style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto" class="MsoNormal"><span style="font-size:12.0pt;font-family:"Tw Cen MT","sans-serif"">Fax:
814-863-0299<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Tw Cen MT","sans-serif""><a href="mailto:bld17@sa.psu.edu"><span style="color:blue">bld17@sa.psu.edu</span></a><br>
<a title="http://www.sa.psu.edu/" href="http://www.sa.psu.edu/"><span style="color:blue">http://www.sa.psu.edu</span></a> </span><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</body>
</html>