<div dir="ltr">thanks for ur helpfull reply.<br>my network topology is as below<br><br>client----->layer2-[switch]----->[if0]router[if1]-------[isc]dhcp server<br><br>layer2 switch is manager switch----192.168.1.46/24<br>
router interface0 -----<a href="http://192.168.1.1/24">192.168.1.1/24</a><br>router interface 1---192.168.2.5/24<br>dhcp server ------<a href="http://192.168.2.1/24">192.168.2.1/24</a><br><br>i'm putting giaddr as layer2 switch which is <a href="http://192.168.1.46">192.168.1.46</a><br>
PROBLEM is discover is reached upto the server ,but we dont get any offer<br>routing table is as below<br>#route -en<br>Kernel IP routing table<br><a href="http://192.168.2.0">192.168.2.0</a> <a href="http://0.0.0.0">0.0.0.0</a> <a href="http://255.255.255.0">255.255.255.0</a> U 0 0 0 eth1<br>
<a href="http://192.168.0.0">192.168.0.0</a> <a href="http://0.0.0.0">0.0.0.0</a> <a href="http://255.255.255.0">255.255.255.0</a> U 0 0 0 eth0<br><a href="http://0.0.0.0">0.0.0.0</a> <a href="http://192.168.0.1">192.168.0.1</a> <a href="http://0.0.0.0">0.0.0.0</a> UG 0 0 0 eth0<br>
<br>but when i add static route for <a href="http://192.168.1.1">192.168.1.1</a> on server<br><br>#route -en<br>Kernel IP routing table<br>Destination Gateway Genmask Flags MSS Window irtt Iface<br>
<a href="http://192.168.2.0">192.168.2.0</a> <a href="http://0.0.0.0">0.0.0.0</a> <a href="http://255.255.255.0">255.255.255.0</a> U 0 0 0 eth1<br><a href="http://192.168.1.0">192.168.1.0</a> <a href="http://0.0.0.0">0.0.0.0</a> <a href="http://255.255.255.0">255.255.255.0</a> U 0 0 0 eth1<br>
<a href="http://192.168.0.0">192.168.0.0</a> <a href="http://0.0.0.0">0.0.0.0</a> <a href="http://255.255.255.0">255.255.255.0</a> U 0 0 0 eth0<br><a href="http://0.0.0.0">0.0.0.0</a> <a href="http://192.168.0.1">192.168.0.1</a> <a href="http://0.0.0.0">0.0.0.0</a> UG 0 0 0 eth0<br>
<br>then we got offer we saw on wireshark that<br>discover from <a href="http://192.168.2.5">192.168.2.5</a> to <a href="http://192.168.2.1">192.168.2.1</a><br>offer from <a href="http://192.168.2.1">192.168.2.1</a> to <a href="http://192.168.1.46">192.168.1.46</a><br>
port unreacheable..<br><br>hope that problem is much explore now...<br>thanks in advance<br>regards,<br>abhijit<br><br><br><br><div class="gmail_quote">On Tue, Oct 14, 2008 at 7:02 PM, Glenn Satchell <span dir="ltr"><<a href="mailto:Glenn.Satchell@uniq.com.au">Glenn.Satchell@uniq.com.au</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br>
>Date: Tue, 14 Oct 2008 18:51:35 +0530<br>
<div class="Ih2E3d">>From: "abhijit khadatare" <<a href="mailto:anks030@gmail.com">anks030@gmail.com</a>><br>
>To: <a href="mailto:dhcp-users@isc.org">dhcp-users@isc.org</a><br>
</div>>Subject: Re: help :giaddr<br>
<div class="Ih2E3d">><br>
>Thanks for reply.<br>
>my network topology shown below<br>
><br>
><br>
>client >|------------>layer 2 switch------------>dhcp server<br>
><br>
>layer 2 switch ip <a href="http://192.168.1.46/24" target="_blank">192.168.1.46/24</a><br>
>dhcp server ip <a href="http://192.168.1.2/24" target="_blank">192.168.1.2/24</a><br>
>i recognised the problem<br>
>problem is in dhcpd.conf<br>
>i checked in conf file that<br>
><br>
>if exists agent.circuit-id {<br>
>option agent.circuit-id = option agent.circuit-id ;<br>
><br>
>log(info , ("echo back circuit-id"));<br>
><br>
>}<br>
><br>
>if exists agent.remote-id {<br>
>option agent.remote-id = option agent.remote-id ;<br>
>}<br>
><br>
>when giaddr =0 that contain opt82 frame then it is go working<br>
>but when giaddr non zero (request from different subnet)<br>
>server itself echo back opt82 frame no need to this checking.<br>
>can u tell me what happen in following scenerio<br>
><br>
>client------>layer2switch:1-------->layer2switch:2------>layer3switch:3----dhcp<br>
>server<br>
><br>
>each layer 2 switch act as relay agent then how giaddr flow,whether it<br>
>should overwrite or not?<br>
>thanks in advance.<br>
<br>
</div>Each of the switches is configured to forward the dhcp broadcast<br>
requests to the dhcp server. dhcp-relays are not configured like a<br>
router with the next hop, rather each is configured with the<br>
destination dhcp server.<br>
<br>
<br>
For the client in the example above layer2switch:1 acts as a relay<br>
agent and uses unicast to forward the request to the dhcp server. The<br>
other switches do not see the broadcast and are not involved in the<br>
relaying of this client's request. The unicast packet will have<br>
layer2switch:1's address in the giaddr field.<br>
<br>
regards,<br>
<font color="#888888">-glenn<br>
<br>
<br>
</font></blockquote></div><br></div>