Thank you all! Sent from my ¥brant° On Feb 29, 2012 10:33 AM, "Rob Pool" <[email protected]> wrote:
> I believe that option 66 could be used to provide tftp for any end host > including a phone. In my environment, we have option 66 providing tftp for > our wireless APs and option 150 for our phones. I've including just a bit > of information I found relevant from one of the CUCM docs. > > Understanding How Devices Identify the TFTP Server > The phones have an order of preference that they use for selecting the > address of the TFTP (Trivial File Transfer Protocol) server. If the devices > receive conflicting or confusing information from the DHCP server, the > device uses the following sequence to determine what information is valid: > *1. *You can locally configure the phone with a TFTP server. This address > overrides any TFTP address sent by the DHCP server. The phone always tries > to resolve the DNS name CiscoCM1. > *2. *If this name is resolved, then it overrides all information sent by > the DHCP server. > > It is not necessary to name the TFTP server CiscoCM1, but you must enter a > DNS CName record to associate CiscoCM1 with the address or name of the TFTP > server. > *3. *The phone uses the value of Next-Server in the boot processes. This > DHCP configuration parameter has traditionally been used as the address of > the TFTP server. When configuring BOOTP servers, this field is typically > referred to as the address of the TFTP server. > > This information is returned in the siaddr field of the DHCP header. You > should always use this option, if available, because some DHCP servers will > place their own IP address in this field when it is not configured. > *4. *The phone uses the site-specific option 150. > *5. *The phone also accepts the Optional Server Name parameter. This DHCP > configuration parameter is the DNS name of a TFTP server. Currently only a > DNS name can be configured in this parameter; a dotted decimal IP address > should not be used. > *6. *The phone also accepts the 66 option, which is the name of the boot > server. > *7. *Option 66 is normally used to replace the sname field when option > overloading occurs. It can be used on Windows NT DHCP servers and functions > like the 150 option. This name field can contain a DNS name or a dotted > decimal IP address. > *8. *The 66 option should not be used with the 150 option. If they are > sent together, then the phone prefers the IP address over the name given by > the 66 option. However, if both a dotted decimal IP address and a 150 > option are sent, then order of preference is dependent on the order that > they appear in the option list. The phone chooses the last item in the > option list. To reiterate, option 66 and option 150 are mutually exclusive. > > *From:* Vijaya Laxmi <[email protected]> > *To:* Rob Pool <[email protected]> > *Cc:* "[email protected]" <[email protected]> > *Sent:* Wednesday, February 29, 2012 10:33 AM > *Subject:* Re: [OSL | CCIE_RS] DHCP options > > So 66 (tftp srvr) is for end hosts ,router interfaces etc other than ip > phone > And 150 is for ip phone > VJ > Sent from my ¥brant° > On Feb 29, 2012 9:11 AM, "Rob Pool" <[email protected]> wrote: > > I believe it's options 66 and 150. > > *From:* Vijaya Laxmi <[email protected]> > *To:* [email protected] > *Sent:* Wednesday, February 29, 2012 9:11 AM > *Subject:* [OSL | CCIE_RS] DHCP options > > Hello, > > Can you tell me what DHCP option does a client use to request TFTP server > address ? > > Also what option is used for ipo phones to grab their ip address and > config ? is it the same option# as above ? > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com <http://www.platinumplacement.com/> > > http://onlinestudylist.com/mailman/listinfo/ccie_rs > > > > > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com http://onlinestudylist.com/mailman/listinfo/ccie_rs
