DHCP Relay with seperate interfacehttps://community.sophos.com/utm-firewall/f/management-networking-logging-and-reporting/34599/dhcp-relay-with-seperate-interfaceHi, Have used DHCP Relay before with success (in switches), but this configuration seems to get me in trouble, maybe the UTM does not support this, but I hope you guys can shed some light into this [:)] Network is connected like this: LAN: Networken-USTelligent Community 12RE: DHCP Relay with seperate interfacehttps://community.sophos.com/thread/432796?ContentTypeID=1Mon, 23 Mar 2020 16:23:46 GMT4be5eb7d-caa4-4ff5-8e60-8f9463545a35:10ff30f5-b424-454d-80e9-38ad87f3faddThomasS1<p>Thank for this post.</p> <p>The same here : adding the DHCP Server subnet interface solved the problem.</p> <p>That is on the doc, but adding the DHCP Server subnet interface is not the first idea.</p><div style="clear:both;"></div>RE: DHCP Relay with seperate interfacehttps://community.sophos.com/thread/118208?ContentTypeID=1Fri, 05 Dec 2014 10:01:05 GMT4be5eb7d-caa4-4ff5-8e60-8f9463545a35:77918e01-dd36-464b-89a7-3077e9032194gregdThe&nbsp;above&nbsp;happened&nbsp;to&nbsp;me&nbsp;too&nbsp;and&nbsp;figured&nbsp;it&nbsp;out&nbsp;by&nbsp;experimenting.&nbsp;&nbsp;I&nbsp;had&nbsp;relays&nbsp;on&nbsp;the&nbsp;network&nbsp;interfaces&nbsp;and&nbsp;an&nbsp;ip&nbsp;helper&nbsp;on&nbsp;the&nbsp;Cisco&nbsp;router,&nbsp;but&nbsp;overlooked&nbsp;the&nbsp;fact&nbsp;I&nbsp;needed&nbsp;one&nbsp;on&nbsp;the&nbsp;interface&nbsp;where&nbsp;the&nbsp;DHCP&nbsp;server&nbsp;was&nbsp;directly&nbsp;connected...&nbsp;[:)]<div style="clear:both;"></div>RE: DHCP Relay with seperate interfacehttps://community.sophos.com/thread/118207?ContentTypeID=1Mon, 01 Dec 2014 02:22:04 GMT4be5eb7d-caa4-4ff5-8e60-8f9463545a35:9949413e-c0d6-4daf-b2b9-69668ead9098twister5800Thanks&nbsp;to&nbsp;you&nbsp;both&nbsp;for&nbsp;replying! <br /> <br /><blockquote cite="will32;280609">&nbsp;Do&nbsp;you&nbsp;also&nbsp;have&nbsp;the&nbsp;interface&nbsp;to&nbsp;the&nbsp;DHCP&nbsp;server&nbsp;listed&nbsp;in&nbsp;the&nbsp;&quot;Interfaces&quot;&nbsp;box? <br /></blockquote> <br /> <br />Exactly&nbsp;THIS&nbsp;fixed&nbsp;my&nbsp;problems,&nbsp;now&nbsp;it&nbsp;works&nbsp;out&nbsp;of&nbsp;the&nbsp;box&nbsp;and&nbsp;it&#39;s&nbsp;stable!!&nbsp;[;)] <br /> <br />Should&nbsp;have&nbsp;read&nbsp;the&nbsp;manual&nbsp;more&nbsp;thoroughly&nbsp;[8-)]: <br /> <br /><blockquote>Add&nbsp;the&nbsp;interfaces&nbsp;involved. <br /> <br />Add&nbsp;the&nbsp;interface&nbsp;to&nbsp;the&nbsp;DHCP&nbsp;server&nbsp;as&nbsp;well&nbsp;as&nbsp;all&nbsp;interfaces&nbsp;to&nbsp;the&nbsp;clients&#39;&nbsp;network(s)&nbsp;between&nbsp;which&nbsp;DHCP&nbsp;requests&nbsp;and&nbsp;responses&nbsp;should&nbsp;be&nbsp;forwarded. <br /></blockquote> <br /> <br />Again&nbsp;THANKS&nbsp;[:)]<div style="clear:both;"></div>RE: DHCP Relay with seperate interfacehttps://community.sophos.com/thread/118206?ContentTypeID=1Sun, 30 Nov 2014 17:34:01 GMT4be5eb7d-caa4-4ff5-8e60-8f9463545a35:6c5f4dd2-ea17-4717-89c2-ae1d8e0b0a21Will32Martin,&nbsp;I&nbsp;am&nbsp;relatively&nbsp;new&nbsp;to&nbsp;the&nbsp;Astaro&nbsp;world,&nbsp;but&nbsp;I&nbsp;am&nbsp;currently&nbsp;doing&nbsp;DHCP&nbsp;relay&nbsp;on&nbsp;my&nbsp;L3&nbsp;switch&nbsp;and&nbsp;using&nbsp;the&nbsp;UTM&nbsp;as&nbsp;my&nbsp;DHCP&nbsp;server.&nbsp;&nbsp;If&nbsp;I&nbsp;understand&nbsp;the&nbsp;DHCP&nbsp;relay&nbsp;setup&nbsp;requirements&nbsp;correctly&nbsp;on&nbsp;Sophos&nbsp;UTM,&nbsp;<b>all</b>&nbsp;interfaces&nbsp;involved&nbsp;in&nbsp;the&nbsp;DHCP&nbsp;relay&nbsp;have&nbsp;to&nbsp;be&nbsp;specified.&nbsp;Do&nbsp;you&nbsp;also&nbsp;have&nbsp;the&nbsp;interface&nbsp;to&nbsp;the&nbsp;DHCP&nbsp;server&nbsp;listed&nbsp;in&nbsp;the&nbsp;&quot;Interfaces&quot;&nbsp;box? <br /> <br />DHCP&nbsp;RELAY&nbsp;ENABLED: <br />&nbsp;SERVER&nbsp;TO&nbsp;RELAY&nbsp;TO&nbsp;IS&nbsp;10.30.32.5 <br />&nbsp;INTERFACE&nbsp;TO&nbsp;RELAY&nbsp;FROM&nbsp;IS:&nbsp;SEPERATE&nbsp;INTERFACE&nbsp;(WLAN0) <br /> <br />Will<div style="clear:both;"></div>RE: DHCP Relay with seperate interfacehttps://community.sophos.com/thread/118205?ContentTypeID=1Sun, 30 Nov 2014 15:02:38 GMT4be5eb7d-caa4-4ff5-8e60-8f9463545a35:0d179536-a755-40f3-b577-7ce15996c13cBAlfsonMartin,&nbsp;I&nbsp;always&nbsp;use&nbsp;a&nbsp;UTM&nbsp;DHCP&nbsp;server&nbsp;for&nbsp;Guest&nbsp;wlans.&nbsp;&nbsp;I&nbsp;have&nbsp;used&nbsp;DHCP&nbsp;relay&nbsp;successfully&nbsp;in&nbsp;the&nbsp;past&nbsp;on&nbsp;two&nbsp;Ethernet&nbsp;interfaces,&nbsp;but&nbsp;that&nbsp;probably&nbsp;was&nbsp;before&nbsp;9.2.<br /><br />Cheers&nbsp;-&nbsp;Bob<div style="clear:both;"></div>RE: DHCP Relay with seperate interfacehttps://community.sophos.com/thread/118204?ContentTypeID=1Sun, 30 Nov 2014 06:32:42 GMT4be5eb7d-caa4-4ff5-8e60-8f9463545a35:ae4911f6-3a19-4ef9-81ed-b5122ab4065ctwister5800Update&nbsp;again:<br /><br />Tried&nbsp;to&nbsp;test&nbsp;on&nbsp;normal&nbsp;eth&nbsp;interface,&nbsp;so&nbsp;not&nbsp;using&nbsp;a&nbsp;seperate&nbsp;wlan0&nbsp;interface,&nbsp;but&nbsp;a&nbsp;standard&nbsp;ethernet&nbsp;connection,&nbsp;the&nbsp;issue&nbsp;is&nbsp;the&nbsp;same&nbsp;here.<br /><br />So&nbsp;this&nbsp;is&nbsp;generally&nbsp;a&nbsp;problem&nbsp;with&nbsp;DHCp&nbsp;Relay...<div style="clear:both;"></div>RE: DHCP Relay with seperate interfacehttps://community.sophos.com/thread/118203?ContentTypeID=1Sun, 30 Nov 2014 06:07:05 GMT4be5eb7d-caa4-4ff5-8e60-8f9463545a35:69640df3-8b5d-4b3b-a106-7e5908d63b55twister5800I&nbsp;have&nbsp;now&nbsp;tried&nbsp;with&nbsp;some&nbsp;debugging&nbsp;on&nbsp;the&nbsp;DHCP&nbsp;server,&nbsp;the&nbsp;log&nbsp;here&nbsp;shows&nbsp;this: <br /> <br /><pre>DHCPDISCOVER&nbsp;for&nbsp;&nbsp;(Martins-Mini)&nbsp;from&nbsp;RelayAgent&nbsp;10.10.10.1&nbsp;rec <br />eived <br />Host&nbsp;&nbsp;(Martins-Mini)&nbsp;offered&nbsp;10.10.10.133 <br />DHCPDISCOVER&nbsp;for&nbsp;&nbsp;(Martins-Mini)&nbsp;from&nbsp;RelayAgent&nbsp;10.10.10.1&nbsp;rec <br />eived <br />Host&nbsp;&nbsp;(Martins-Mini)&nbsp;offered&nbsp;10.10.10.133 <br />DHCPDISCOVER&nbsp;for&nbsp;&nbsp;(Martins-Mini)&nbsp;from&nbsp;RelayAgent&nbsp;10.10.10.1&nbsp;rec <br />eived <br />Host&nbsp;&nbsp;(Martins-Mini)&nbsp;offered&nbsp;10.10.10.133</pre> <br /> <br />MAC&nbsp;address&nbsp;is&nbsp;removed&nbsp;in&nbsp;this&nbsp;post... <br /> <br />So&nbsp;the&nbsp;packets&nbsp;get&nbsp;through&nbsp;the&nbsp;UTM&nbsp;to&nbsp;the&nbsp;DHCP&nbsp;server,&nbsp;but&nbsp;somehow&nbsp;they&nbsp;cannot&nbsp;find&nbsp;their&nbsp;way&nbsp;back?&nbsp;[:S]<div style="clear:both;"></div>RE: DHCP Relay with seperate interfacehttps://community.sophos.com/thread/118202?ContentTypeID=1Sun, 30 Nov 2014 05:33:58 GMT4be5eb7d-caa4-4ff5-8e60-8f9463545a35:8d243e4e-b1b3-4455-ae4f-be86593f2cc7twister5800A&nbsp;little&nbsp;update:<br /><br />I&nbsp;have&nbsp;now&nbsp;setup&nbsp;this&nbsp;in&nbsp;my&nbsp;homelab,&nbsp;it&nbsp;worked,&nbsp;after&nbsp;5&nbsp;minutes&nbsp;of&nbsp;time,&nbsp;but&nbsp;when&nbsp;I&nbsp;release&nbsp;I&nbsp;cannot&nbsp;get&nbsp;a&nbsp;new&nbsp;address&nbsp;again.<br /><br />I&nbsp;have&nbsp;two&nbsp;wireless&nbsp;clients,&nbsp;the&nbsp;other&nbsp;client&nbsp;never&nbsp;get&#39;s&nbsp;an&nbsp;address&nbsp;from&nbsp;the&nbsp;relay&nbsp;server,&nbsp;but&nbsp;the&nbsp;first&nbsp;client&nbsp;got&nbsp;one&nbsp;and&nbsp;it&nbsp;shoed&nbsp;up&nbsp;in&nbsp;the&nbsp;lease&nbsp;table&nbsp;of&nbsp;the&nbsp;server.<br /><br />Either&nbsp;this&nbsp;is&nbsp;not&nbsp;a&nbsp;supported&nbsp;setup&nbsp;or&nbsp;there&nbsp;is&nbsp;a&nbsp;bug&nbsp;in&nbsp;the&nbsp;UTm&nbsp;somewere...<br /><br />The&nbsp;IPS&nbsp;log&nbsp;shows&nbsp;nothing...<div style="clear:both;"></div>