The router does that for you, by requesting from the address from which it originally received the broadcast. The DHCP server sees that address and responds with an address from the same subnet, if a scope is configured which matches it.
I'm sure that's a pretty crude description, but I believe basically how it works. Gaz ""Logan, Harold"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > That's kind of why I was asking... I understand the significance of the > helper addy. From there, DHCP requests get sent to a single DHCP server, > that presumably has multiple scopes configured, one scope per > subnet/VLAN. What do you do on the DHCP server to make it so that, when > a host a VLAN requests an address, the DHCP server answers with an > address from the appropriate scope? > > Thanks, > Hal > > > > -----Original Message----- > > From: Gaz [mailto:[EMAIL PROTECTED]] > > Sent: Monday, November 26, 2001 2:16 PM > > To: [EMAIL PROTECTED] > > Subject: Re: multiple DHCP scopes in a vlan with primary an [7:27264] > > > > > > The original question, sorry can't remember who by, was whether this > > configuration could be used for a VLAN which had Primary and > > Secondary IP > > addresses. The IP helper address only specifies the DHCP server. > > > > I'm fairly sure this could not work effectively, although > > DHCP clients would > > be issued with addresses. > > My thought was that the IP addresses issued would always be > > in the subnet of > > the primary address. > > > > Anybody confirm or deny?? > > > > Cheers, > > > > Gaz > > > > ""Lange, Eric"" wrote in message > > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > The ip helper-address command is your buddy. The router > > can convert a UDP > > > broadcast packet into a unicast and route the packet to the > > appropriate > > > network that the DHCP server resides on. > > > > > > -Eric > > > > > > -----Original Message----- > > > From: Logan, Harold [mailto:[EMAIL PROTECTED]] > > > Sent: Monday, November 26, 2001 11:41 AM > > > To: [EMAIL PROTECTED] > > > Subject: RE: multiple DHCP scopes in a vlan with primary an > > [7:27264] > > > > > > > > > For those of you that have implemented VLANs with DHCP, do > > you use one > > > DHCP server per VLAN, or is there a way to bind a specific > > DHCP scope to > > > each VLAN? > > > > > > Thanks, > > > Hal > > > > > > > > > > -----Original Message----- > > > > From: Syed Raza [mailto:[EMAIL PROTECTED]] > > > > Sent: Monday, November 26, 2001 11:59 AM > > > > To: [EMAIL PROTECTED] > > > > Subject: Re: multiple DHCP scopes in a vlan with primary > > an [7:27264] > > > > > > > > > > > > It is not recommended to have multiple subnet in one VLAN. > > > > Basically you are > > > > killing the whole concept of isolating the broadcast domain. > > > > But you can not > > > > argue that it does'nt work. Your DHCP server can assign any > > > > ip from its > > > > scopes. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27367&t=27264 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
