<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Verdana; font-size: 10pt; color: #000000'>I also noticed that for IOS v15T, it has the following pre-requisites. However, I can't find a "service dhcp" statement in my config, but I know it's offering up DHCP addresses. Also, I can't issue the "show ip sockets details" command or the "show sockets detail" command.<br><br>weird!<br><br><div style="margin-left: 40px;"><hr style="width: 100%; height: 2px;">http://www.cisco.com/en/US/docs/ios-xml/ios/ipaddr_dhcp/configuration/15-1mt/Configuring_the_Cisco_IOS_DHCP_Server.html#GUID-9F0ED96D-17EA-4307-A14C-0C23A335B5D4<br><br><span class="content"><div>
<p>
Before you configure the Cisco IOS DHCP server, you should understand the concepts documented in the DHCP Overview module.</p><p><br></p>
<p>
The Cisco IOS DHCP server and relay agent are enabled by default. You
can verify if they have been disabled by checking your configuration
file. If they have been disabled, the <span class="synph"><span class="kwd">no</span> <span class="kwd">service</span> <span class="kwd">dhcp</span></span> command will appear in the configuration file. Use the <span class="synph"><span class="kwd">service</span> <span class="kwd">dhcp</span></span> command to reenable the functionality if necessary. <br></p><p><br></p>
<p>
Port 67 (the server port) is closed in the Cisco IOS DHCP/BOOTP default configuration. There are two logical parts to the <span class="synph"><span class="kwd">service</span> <span class="kwd">dhcp</span></span>
command: service enabled and service running. The DHCP service is
enabled by default, but port 67 is not opened until the DHCP service is
running. If the service is running, the <span class="synph"><span class="kwd">show</span> <span class="kwd">ip</span> <span class="kwd">sockets</span> <span class="kwd">details</span></span> or <span class="synph"><span class="kwd">show</span> <span class="kwd">sockets</span> <span class="kwd">detail</span></span> command displays port 67 as open.</p><p><br></p>
<p>
The Cisco IOS DHCP relay agent will be enabled on an interface only when the <span class="synph"><span class="kwd">ip</span> <span class="kwd">helper-address</span></span> is configured. This command enables the DHCP broadcast to be forwarded to the configured DHCP server.</p>
</div></span><br><hr style="width: 100%; height: 2px;"></div><span><br><span name="x"></span>---<br>Lelio Fulgenzi, B.A.<br>Senior Analyst (CCS) * University of Guelph * Guelph, Ontario N1G 2W1<br>(519) 824-4120 x56354 (519) 767-1060 FAX (JNHN)<br>^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^<br>Cooking with unix is easy. You just sed it and forget it. <br> - LFJ (with apologies to Mr. Popeil)<br><span name="x"></span><br></span><br><hr id="zwchr"><b>From: </b>"Robert Kulagowski" <rkulagow@gmail.com><br><b>To: </b>"cisco-voip (cisco-voip@puck.nether.net)" <cisco-voip@puck.nether.net><br><b>Sent: </b>Tuesday, May 10, 2011 11:23:59 AM<br><b>Subject: </b>Re: [cisco-voip] suggested/best practices for DHCP settings on routers<br><br>On Mon, May 9, 2011 at 3:16 PM, Ryan Ratliff <rratliff@cisco.com> wrote:<br>> An address conflict occurs when two hosts use the same IP address. During<br>> address assignment, DHCP checks for conflicts using ping and gratuitous<br>> Address Resolution Protocol (ARP). If a conflict is detected, the address is<br>> removed from the pool. The address will not be assigned until the<br>> administrator resolves the conflict.<br>><br>> Yes it does.<br>> -Ryan<br><br>We ended up adding:<br><br>no ip dhcp conflict logging<br><br>to our router configuration so that we wouldn't end up with _all_<br>addresses unassignable.<br>_______________________________________________<br>cisco-voip mailing list<br>cisco-voip@puck.nether.net<br>https://puck.nether.net/mailman/listinfo/cisco-voip<br></div></body></html>