DHCP Snooping Implementation

[Joel Wilson]

I'm in the process of implementing DHCP snooping for a customer. I'm looking for some information on how many databases I should implement for a campus of 95 3750 switches and 20 6509s. Or do I need to have a single database per switch? Also, what kind of load will the switches communicating with the database create on a TFTP or FTP server? I'm guessing the switches will only hit the TFTP server in the event they are rebooted. Any guidance will be appreciated. Thanks.

[owillins · Accepted solution]

Try this link for more information on DHCP-snooping

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat4000/12_2_18/config/dhcp.htm

[pkrohn]

Hi - not really sure I understand your question. The DHCP snooping database or table is local to the switch, and is build dynamically for each VLAN where DHCP snooping is enabled. Check http://www.cisco.com/en/US/partner/products/hw/switches/ps708/products_configuration_guide_chapter09186a0080435791.html#wp1114389

[autobot130]

I'm not sure the question is fully understood but DHCP snooping is implemented on ACCESS layer switches that the end-users are *directly connected* into.

Be sure to do "dhcp trust" ports on the uplink of the access switch.

Pretty simple, Read the link that others have posted previously. But essentially, its a two step process. 1. enable globally 2. enable dhcp trust ports.

[kamal-learn]

hi

to find out the number of databases to use i think an understanding of why use DHCP snooping is required!!

as i know the dhcp snooping is used to mitigate arp spoofing,how that? i.e in the case of a mac-address claiming having an ip-address ,the ios check with the dhcp binding database to verify if that is true or not, so which DHCP ?? is the one to it the mac-address registred with to get an IP-address, if you are using 10 DHCP server so you need 10 databases.

HTH

PLS rate if it does helps