DHCP requests will be sent to each server, the host will select which ever server's reply was recieved back first. The router will forward the dhcp broadcast as a unicast packet to the dhcp servers and populate the giaddr field with the primary IP address on the interface (secondary addresses are ignored/not put in the giaddr field).
interface vlan 10
ip address 10.10.10.1 255.255.255.0
ip address 10.10.11.1 255.255.255.0 secondary
ip helper-address 192.168.10.1
If your dhcp server is using the giaddr field to determine the scope to hand out from, you need to ensure that both IP address ranges are part of the same scope (eg. with the 10.10.10.0 range being the primary scope and 10.10.11.0 being the secondary).
You can put a sniffer on to see what is happening if you want.
The router will forward the DHCP request braodcast, a.k.a. the DHCPDISCOVER packet, to all ip helper adresses.
All DHCP servers will respond with a DHCPOFFER. The client will choose one and reply with a DHCPREQUEST packet that informs the chosen server to complete the exchange while also informing the other servers that their offer has been declined.
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...