Hi Chris, Remember you can use the master index to search in as well, so you can find things from there particularly if you are more interested in the command reference and you know how how the command starts (e.g. ip dhcp) and sometimes you'll find more of the options described here.
For R2 Fa0/0.21 - you can do it that way, or alternatively on Cat1 you could have "no ip dhcp relay information option" - the end result is the same but the important thing to know is dhcp snooping is a class of dhcp relay and IOS dhcp servers doesn't like it when the giaddr field is empty (in a normal relay circumstance without dhcp option 82 this is used to help identify the subnet the dhcp client should be associated with) - so for dhcp snooping (which normally sets giaddr to 0 and uses dhcp option 82 to do things like identify which port the client is connected to on the switch so the dhcp server can make a more informed decision when it comes down to address allocation) to properly work in a basic IOS environment you either get the switch to not send the info, or you get the router to know its ok if it receives it. Assigning IP Addresses based DHCP client MAC Addresses is used as a fallback if the client doesn't send a dhcp client-id (IOS Devices send these and I don't believe it can be disabled) an example of a dumber device could be a printer or something that doesn't have as rich dhcp client software as the routers and switches, so I expect this to work for your switch. Definitely I use the debug ip dhcp server packet to obtain the client identifier for copy and pasting into the config if I cant hard set things myself, because the default client string is a convoluted mess that shouldn't be derived by hand :) (to give an example on how to hard set things yourself without needing debugs on the dhcp server) On Cat1 int vlan 21 ip dhcp client client-id hex 1234 On R2 ip dhcp pool Cat1 client-identifier 1234 As I'm sure you've discovered there is typically more than one way to do things in IOS, sometimes the lab will restrict which methods can be used so being aware of what the alternatives may be and how to hunt down how to implement it is essential but at the same time you aren't going to have a lot of time up your sleeve to be cruising through the documentation so rapid search techniques coupled with a solid working knowledge of the core blueprint topics is essential. Cheers, Adam On Wed, Jan 4, 2012 at 10:13 AM, Christopher Lemish < [email protected]> wrote: > Anyone, > > This DHCP configuration is as follows. Does anyone know where to find > this in the DocCD should this be on the lab and we don't know exactly how > to configure it? Do we have to have this procedure memorized or we will > lose the points? Does anyone know if the debug has to be done to get the > string? I recall Marko using the MAC address of the remote interface and > pasted that in when configuring the client-identifier. > > 6.1 > > R2 > --- > //dhcp snooping was configured on vlan21 in an earlier task > > R2 > --- > ip dhcp pool VLAN21 > netw 70.18.21.0 /24 > update arp > exit > ! > ip dhcp pool Cat1 > host 70.18.21.10 255.255.255.0 > update arp > ! > int f0/0.21 > ip dhcp relay info trusted > ! > debug ip dhcp server packet > > //get the information (sting of digits, then you can paste it into) > ip dhcp pool Cat1 > client-identifier f.2d30.3030.642e.3238.3866.2e30.3330.302d.566c.3231 > > Cat1 > ----- > int fa0/2 > ip dhcp snooping trust > int vlan 21 > ip add dhcp > > > > Thank you, > Chris > > > _______________________________________________ > 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 > _______________________________________________ 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
