RE: Can you use DHCP to assign an address to the downstream interface used by dhcrelay?
"Vallevand, Mark K" <[email protected]> Wed, 28 Feb 2024 13:36:26 +0000
| Newsgroups | gmane.network.dhcp.isc.dhcp-server |
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--===============8306851852516403671== Content-Language: en-US Content-Type: multipart/related; boundary="_004_CO3PR07MB9271FE584C28ADE87E0A5E85EA582CO3PR07MB9271namp_"; type="multipart/alternative" --_004_CO3PR07MB9271FE584C28ADE87E0A5E85EA582CO3PR07MB9271namp_ Content-Type: multipart/alternative; boundary="_000_CO3PR07MB9271FE584C28ADE87E0A5E85EA582CO3PR07MB9271namp_" --_000_CO3PR07MB9271FE584C28ADE87E0A5E85EA582CO3PR07MB9271namp_ Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Basically, it was a project requirement to allow a DHCP address on the dhcp= _relay interface. Regards. Mark K Vallevand Unisys 651-635-7708 | [email protected]<mailto:mark.vallevand@unisy= s.com> [cid:[email protected]]<http://www.unisys.com/> From: dhcp-users <[email protected]> On Behalf Of Renyk de'V= andre Sent: Wednesday, February 28, 2024 6:53 AM To: Users of ISC DHCP <[email protected]> Subject: RE: Can you use DHCP to assign an address to the downstream interf= ace used by dhcrelay? Hi All, Re: below Just read this and it had me curious, can you explain why= you don't want to or can't set a static IP address on your dhcp relay inte= rface? It would be good to see your basic topology: i.=E2=80=8Ae. DHCP SERV= ER <--> routing infrastructure Hi All, Re: below Just read this and it had me curious, can you explain why you don't want to= or can't set a static IP address on your dhcp relay interface? It would = be good to see your basic topology: i.e. DHCP SERVER <--> routing infrastructure <--> edge router <--> switched= infrastructure 1 <--> dhcprelay requiring dhcp lease for relay interface = <--> switched infrastructure 2 <--> client requiring dhcp lease My thoughts were: 1. (what is the dhcprelay running on) 2. Are the switched infrastructure 1 and switched infrastructure 2 separ= ate i.e. broadcasts from 2 and 1 are separate? If that was the case (just thinking out loud here) I first thought you coul= d you put an ip helper on the edge router which would listen for the broadc= ast from the dhcprelay interface address and assign an address, however thi= s would not work because this would only work for assigning an address to t= he upstream interface between edge router and switched infrastructure 1....= so I totally agree below I can't see how this could be made to work...= . and if the switched infrastructure 1 and 2 are collapsed with the edge = router and dhcprelay on the same switched network then why do you need the = dhcprelay instead of using the edge router/vlan interface and ip helpers...= . (all conjecture here). but back to my main thought, what is the reason for not wanting to assign t= he static address on the dhcp-relay.. Ren -----Original Message----- From: dhcp-users <[email protected]<mailto:dhcp-users-bounce= [email protected]>> On Behalf Of Simon Sent: Friday, February 2, 2024 12:43 PM To: Users of ISC DHCP <[email protected]<mailto:[email protected]= .org>> Subject: Re: Can you use DHCP to assign an address to the downstream interf= ace used by dhcrelay? CAUTION: This email originated from outside the organisation. Do not click = links or open attachments unless you recognise the sender and know the cont= ent is safe. On 2 Nov 2023, at 17:13, Vallevand, Mark K <[email protected]<mailt= o:[email protected]>> wrote: > I have configured dhcrelay upstream and downstream interfaces and a serve= r address. > DHCP addresses are correctly relayed from machines on the downstream side= to the upstream side and back. > Rather than using a static address in the downstream interface, I would l= ike to assign a DHCP address using dhclient to the downstream interface. > Dhcrelay does not seem to handle this case. If the origin of the request= is the actual downstream interface, it is not relayed. > Is this possible? Can I use dhclient to get an address for the downstrea= m interface used by dhcrelay? Sorry, I=E2=80=99ve not had time to keep up here for a bit - I see this one= seems to have gone unanswered. Unfortunately, you are in a catch-22 situation here. If the downstream inte= rface doesn=E2=80=99t have an IP address then presumably the relay cannot f= ill in the GI-Addr field. If it can=E2=80=99t fill in the GI-Addr field, th= en the server can=E2=80=99t locate the interface in order to offer an addre= ss. To get around this situation, you=E2=80=99d need to configure the device in= some way before it could then use DHCP to get an address for the downstrea= m - and once you=E2=80=99ve set this up, you might as well just configure t= he interface. Alternatively, you might be able to do some =E2=80=9Cfudge=E2=80=9D to get = a subnet from the server (similar to the way IPv6 Prefix Delegations can be= done) and then use an algorithm to configure the interface (e.g. pick the = lowest usable address in the subnet). The DHCP server would need some way o= f associating the request with the device - and of course it needs the subn= et details (such as router) configured anyway in order to hand them to the = clients. However, I think your observation is a separate implementation specific lim= itation. Because of the need to handle unaddressed packets (i.e. it needs t= o receive and send broadcasts from/to the clients before they have an IP ad= dress) I assume the relay agent shares code with the server in using a raw = packet interface rather than going through the IP stack. You can=E2=80=99t = have two bits of software doing this, and in any case running a client woul= d result in a broadcast packet OUT of the interface which would not be seen= as an incoming packet by the relay agent. I assume not the answer you were looking for, but at least you now understa= nd why it isn=E2=80=99t working. Simon -- ISC funds the development of this software with paid support subscriptions.= Contact us at https://urldefense.com/v3/__https://www.isc.org/contact/__;!= !JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-F4_1JX0maGRCC8VJKlEp= 9Z9ketI9y1X75F4kYqYjYoMxYoa0Q$<https://urldefense.com/v3/__https:/www.isc.o= rg/contact/__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-F4_1J= X0maGRCC8VJKlEp9Z9ketI9y1X75F4kYqYjYoMxYoa0Q$> for more information. dhcp-users mailing list [email protected]<mailto:[email protected]> https://urldefense.com/v3/__https://lists.isc.org/mailman/listinfo/dhcp-use= rs__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-F4_1JX0maGRCC8= VJKlEp9Z9ketI9y1X75F4kYqYjYovADBLZg$<https://urldefense.com/v3/__https:/lis= ts.isc.org/mailman/listinfo/dhcp-users__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4x= o_tNVl2AEzFq0KiKNKUKG-F4_1JX0maGRCC8VJKlEp9Z9ketI9y1X75F4kYqYjYovADBLZg$> -- ISC funds the development of this software with paid support subscriptions.= Contact us at https://urldefense.com/v3/__https://www.isc.org/contact/__;!= !JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-F4_1JX0maGRCC8VJKlEp= 9Z9ketI9y1X75F4kYqYjYoMxYoa0Q$<https://urldefense.com/v3/__https:/www.isc.o= rg/contact/__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-F4_1J= X0maGRCC8VJKlEp9Z9ketI9y1X75F4kYqYjYoMxYoa0Q$> for more information. dhcp-users mailing list [email protected]<mailto:[email protected]> https://urldefense.com/v3/__https://lists.isc.org/mailman/listinfo/dhcp-use= rs__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-F4_1JX0maGRCC8= VJKlEp9Z9ketI9y1X75F4kYqYjYovADBLZg$<https://urldefense.com/v3/__https:/lis= ts.isc.org/mailman/listinfo/dhcp-users__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4x= o_tNVl2AEzFq0KiKNKUKG-F4_1JX0maGRCC8VJKlEp9Z9ketI9y1X75F4kYqYjYovADBLZg$> --_000_CO3PR07MB9271FE584C28ADE87E0A5E85EA582CO3PR07MB9271namp_ Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable <html xmlns:v=3D"urn:schemas-microsoft-com:vml" xmlns:o=3D"urn:schemas-micr= osoft-com:office:office" xmlns:w=3D"urn:schemas-microsoft-com:office:word" = xmlns:m=3D"http://schemas.microsoft.com/office/2004/12/omml" xmlns=3D"http:= //www.w3.org/TR/REC-html40"> <head> <meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Dutf-8"> <meta name=3D"Generator" content=3D"Microsoft Word 15 (filtered medium)"> <!--[if !mso]><style>v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} </style><![endif]--><style><!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4;} @font-face {font-family:Consolas; panose-1:2 11 6 9 2 2 4 3 2 4;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {margin:0in; font-size:10.0pt; font-family:"Calibri",sans-serif;} a:link, span.MsoHyperlink {mso-style-priority:99; color:blue; text-decoration:underline;} pre {mso-style-priority:99; mso-style-link:"HTML Preformatted Char"; margin:0in; margin-bottom:.0001pt; font-size:10.0pt; font-family:"Courier New";} span.HTMLPreformattedChar {mso-style-name:"HTML Preformatted Char"; mso-style-priority:99; mso-style-link:"HTML Preformatted"; font-family:Consolas;} span.EmailStyle23 {mso-style-type:personal-compose; font-family:"Calibri",sans-serif; color:windowtext;} .MsoChpDefault {mso-style-type:export-only; font-size:10.0pt; mso-ligatures:none;} @page WordSection1 {size:8.5in 11.0in; margin:1.0in 1.0in 1.0in 1.0in;} div.WordSection1 {page:WordSection1;} --></style><!--[if gte mso 9]><xml> <o:shapedefaults v:ext=3D"edit" spidmax=3D"1026" /> </xml><![endif]--><!--[if gte mso 9]><xml> <o:shapelayout v:ext=3D"edit"> <o:idmap v:ext=3D"edit" data=3D"1" /> </o:shapelayout></xml><![endif]--> </head> <body lang=3D"EN-US" link=3D"blue" vlink=3D"purple" style=3D"word-wrap:brea= k-word"> <div class=3D"WordSection1"> <p class=3D"MsoNormal"><span style=3D"font-size:11.0pt">Basically, it was a= project requirement to allow a DHCP address on the dhcp_relay interface.<o= :p></o:p></span></p> <p class=3D"MsoNormal"><span style=3D"font-size:11.0pt"><o:p> </o:p></= span></p> <p class=3D"MsoNormal"><span style=3D"font-size:11.0pt"><o:p> </o:p></= span></p> <p class=3D"MsoNormal"><span style=3D"font-size:11.0pt"><o:p> </o:p></= span></p> <div style=3D"mso-element:para-border-div;border:none;border-top:solid #CCC= CCC 1.0pt;padding:4.0pt 0in 0in 0in"> <p class=3D"MsoNormal" style=3D"margin-bottom:3.0pt;border:none;padding:0in= "><span style=3D"font-size:11.0pt;font-family:"Arial",sans-serif;= color:#444444">Regards.<o:p></o:p></span></p> <p class=3D"MsoNormal" style=3D"margin-bottom:3.0pt;border:none;padding:0in= "><b><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if;color:#444444"><o:p> </o:p></span></b></p> <p class=3D"MsoNormal" style=3D"margin-bottom:3.0pt;border:none;padding:0in= "><b><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if;color:#444444">Mark K Vallevand</span></b><span style=3D"font-size:11.0p= t;font-family:"Arial",sans-serif;color:#444444"><o:p></o:p></span= ></p> </div> <p class=3D"MsoNormal" style=3D"margin-bottom:3.0pt"><span style=3D"font-si= ze:9.0pt;font-family:"Arial",sans-serif;color:#444444">Unisys 651= -635-7708 | </span><span style=3D"font-size:9.0pt;font-family:"Arial",sans-se= rif"><a href=3D"mailto:[email protected]"><span style=3D"color:#056= 3C1">[email protected]</span></a><span style=3D"color:#444444"> <o:p></o:p></span></span></p> <p class=3D"MsoNormal" style=3D"margin-bottom:3.0pt"><span style=3D"font-si= ze:8.0pt;color:#2072BC"><o:p> </o:p></span></p> <p class=3D"MsoNormal" style=3D"margin-bottom:3.0pt"><a href=3D"http://www.= unisys.com/"><span style=3D"font-size:11.0pt;color:windowtext;text-decorati= on:none"><img border=3D"0" width=3D"124" height=3D"27" style=3D"width:1.291= 6in;height:.2812in" id=3D"Picture_x0020_49" src=3D"cid:image001.png@01DA6A1= 8.D5725450"></span></a><span style=3D"font-size:11.0pt"><o:p></o:p></span><= /p> <p class=3D"MsoNormal"><span style=3D"font-size:11.0pt"><o:p> </o:p></= span></p> <div style=3D"border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in = 0in 0in"> <p class=3D"MsoNormal"><b><span style=3D"font-size:11.0pt">From:</span></b>= <span style=3D"font-size:11.0pt"> dhcp-users <[email protected]= sc.org> <b>On Behalf Of </b>Renyk de'Vandre<br> <b>Sent:</b> Wednesday, February 28, 2024 6:53 AM<br> <b>To:</b> Users of ISC DHCP <[email protected]><br> <b>Subject:</b> RE: Can you use DHCP to assign an address to the downstream= interface used by dhcrelay?<o:p></o:p></span></p> </div> <p class=3D"MsoNormal"><o:p> </o:p></p> <div> <p class=3D"MsoNormal" style=3D"mso-line-height-alt:.75pt"><span style=3D"f= ont-size:1.0pt;color:white">Hi All, Re: below Just read this and it had me = curious, can you explain why you don't want to or can't set a static IP add= ress on your dhcp relay interface? It would be good to see your basic topology: i.=E2=80=8Ae. DHCP SERVER <--= > routing infrastructure <o:p></o:p></span></p> </div> <div> <p class=3D"MsoNormal" style=3D"mso-line-height-alt:.75pt"><span style=3D"f= ont-size:1.0pt;color:white"><o:p></o:p></span></p> </div> <pre style=3D"white-space:pre-wrap"><span style=3D"font-size:11.0pt;font-fa= mily:"Arial",sans-serif">Hi All,<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">Re: below <o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">Just read this and it had me curious, can you explain why you don't wan= t to or can't set a static IP address on your dhcp relay interface? &n= bsp; It would be good to see your basic topology:<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">i.e. <o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">DHCP SERVER <--> routing infrastructure <--&= gt; edge router <--> switched infrastructure 1 <-->= dhcprelay requiring dhcp lease for relay interface <--> = switched infrastructure 2 <--> client requiring dhcp lease<o:p></o:p>= </span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">My thoughts were:<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">1. (what is the dhcprelay running on)<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">2. Are the switched infrastructure 1 and switched infrastru= cture 2 separate i.e. broadcasts from 2 and 1 are separate?<o:p></o:p= ></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">If that was the case (just thinking out loud here) I first thought you = could you put an ip helper on the edge router which would listen for the br= oadcast from the dhcprelay interface address and assign an address, however= this would not work because this would only work for assigning an address = to the upstream interface between edge router and switched infrastructure 1= .... so I totally agree below I can't see how this = could be made to work.... and if the switched infrastructure 1 = and 2 are collapsed with the edge router and dhcprelay on the same switched= network then why do you need the dhcprelay instead of using the edge route= r/vlan interface and ip helpers.... (all conjecture here).<o:p>= </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">but back to my main thought, what is the reason for not wanting to assi= gn the static address on the dhcp-relay..<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">Ren<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">-----Original Message-----<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">From: dhcp-users <<a href=3D"mailto:[email protected]= ">[email protected]</a>> On Behalf Of Simon<o:p></o:p></s= pan></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">Sent: Friday, February 2, 2024 12:43 PM<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">To: Users of ISC DHCP <<a href=3D"mailto:[email protected]">d= [email protected]</a>><o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">Subject: Re: Can you use DHCP to assign an address to the downstream in= terface used by dhcrelay?<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">CAUTION: This email originated from outside the organisation. Do not cl= ick links or open attachments unless you recognise the sender and know the = content is safe.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">On 2 Nov 2023, at 17:13, Vallevand, Mark K <<a href=3D"mailto:Mark.V= [email protected]">[email protected]</a>> wrote:<o:p></o:p></s= pan></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">> I have configured dhcrelay upstream and downstream interfaces and = a server address.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">> DHCP addresses are correctly relayed from machines on the downstre= am side to the upstream side and back.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">> Rather than using a static address in the downstream interface, I = would like to assign a DHCP address using dhclient to the downstream interf= ace.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">> Dhcrelay does not seem to handle this case. If the origin of= the request is the actual downstream interface, it is not relayed.<o:p></o= :p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">> Is this possible? Can I use dhclient to get an address for t= he downstream interface used by dhcrelay?<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">Sorry, I=E2=80=99ve not had time to keep up here for a bit - I see this= one seems to have gone unanswered.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">Unfortunately, you are in a catch-22 situation here. If the downstream = interface doesn=E2=80=99t have an IP address then presumably the relay cann= ot fill in the GI-Addr field. If it can=E2=80=99t fill in the GI-Addr field= , then the server can=E2=80=99t locate the interface in order to offer an a= ddress.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">To get around this situation, you=E2=80=99d need to configure the devic= e in some way before it could then use DHCP to get an address for the downs= tream - and once you=E2=80=99ve set this up, you might as well just configu= re the interface.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">Alternatively, you might be able to do some =E2=80=9Cfudge=E2=80=9D to = get a subnet from the server (similar to the way IPv6 Prefix Delegations ca= n be done) and then use an algorithm to configure the interface (e.g. pick = the lowest usable address in the subnet). The DHCP server would need some w= ay of associating the request with the device - and of course it needs the = subnet details (such as router) configured anyway in order to hand them to = the clients.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">However, I think your observation is a separate implementation specific= limitation. Because of the need to handle unaddressed packets (i.e. it nee= ds to receive and send broadcasts from/to the clients before they have an I= P address) I assume the relay agent shares code with the server in using a = raw packet interface rather than going through the IP stack. You can=E2=80= =99t have two bits of software doing this, and in any case running a client= would result in a broadcast packet OUT of the interface which would not be= seen as an incoming packet by the relay agent.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">I assume not the answer you were looking for, but at least you now unde= rstand why it isn=E2=80=99t working.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">Simon<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">--<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">ISC funds the development of this software with paid support subscripti= ons. Contact us at <a href=3D"https://urldefense.com/v3/__https:/www.isc.or= g/contact/__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-F4_1JX= 0maGRCC8VJKlEp9Z9ketI9y1X75F4kYqYjYoMxYoa0Q$">https://urldefense.com/v3/__h= ttps://www.isc.org/contact/__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzF= q0KiKNKUKG-F4_1JX0maGRCC8VJKlEp9Z9ketI9y1X75F4kYqYjYoMxYoa0Q$</a> for more = information.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">dhcp-users mailing list<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><a href=3D"mailto:[email protected]">[email protected]</a= ><o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><a href=3D"https://urldefense.com/v3/__https:/lists.isc.org/mailman/lis= tinfo/dhcp-users__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-= F4_1JX0maGRCC8VJKlEp9Z9ketI9y1X75F4kYqYjYovADBLZg$">https://urldefense.com/= v3/__https://lists.isc.org/mailman/listinfo/dhcp-users__;!!JZxO7R1e!r_nth26= IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-F4_1JX0maGRCC8VJKlEp9Z9ketI9y1X75F4kY= qYjYovADBLZg$</a><o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">-- <o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">ISC funds the development of this software with paid support subscripti= ons. Contact us at <a href=3D"https://urldefense.com/v3/__https:/www.isc.or= g/contact/__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-F4_1JX= 0maGRCC8VJKlEp9Z9ketI9y1X75F4kYqYjYoMxYoa0Q$">https://urldefense.com/v3/__h= ttps://www.isc.org/contact/__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzF= q0KiKNKUKG-F4_1JX0maGRCC8VJKlEp9Z9ketI9y1X75F4kYqYjYoMxYoa0Q$</a> for more = information.<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><o:p> </o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if">dhcp-users mailing list<o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><a href=3D"mailto:[email protected]">[email protected]</a= ><o:p></o:p></span></pre> <pre><span style=3D"font-size:11.0pt;font-family:"Arial",sans-ser= if"><a href=3D"https://urldefense.com/v3/__https:/lists.isc.org/mailman/lis= tinfo/dhcp-users__;!!JZxO7R1e!r_nth26IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-= F4_1JX0maGRCC8VJKlEp9Z9ketI9y1X75F4kYqYjYovADBLZg$">https://urldefense.com/= v3/__https://lists.isc.org/mailman/listinfo/dhcp-users__;!!JZxO7R1e!r_nth26= IuPN-oPgTpMqOg4xo_tNVl2AEzFq0KiKNKUKG-F4_1JX0maGRCC8VJKlEp9Z9ketI9y1X75F4kY= qYjYovADBLZg$</a><o:p></o:p></span></pre> </div> </body> </html> --_000_CO3PR07MB9271FE584C28ADE87E0A5E85EA582CO3PR07MB9271namp_-- --_004_CO3PR07MB9271FE584C28ADE87E0A5E85EA582CO3PR07MB9271namp_ Content-Type: image/png; 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