Answer is D and E https://community.cisco.com/t5/switching/cisco-router-configured-as-a-dhcp-server-not-replying-to-quot/td-p/3206932 1.- The relay agent was configured by default with "no service dhcp". This made the relayed packets come from 0.0.0.0 instead of 10.2.1.1 2.- The DHCP server needs to be configured with "ip dhcp relay information trust-all" so it processes relayed packets with no Giaddr field

Selected Answer: DE See https://community.cisco.com/t5/switching/cisco-router-configured-as-a-dhcp-server-not-replying-to-quot/td-p/3206932

Selected Answer: DE D & E for sure, references: ip dhcp relay information trust-all : This command is useful if there is a switch between the client and the relay agent that may insert option 82. Use this command to make sure these packets are not dropped. https://www.cisco.com/en/US/docs/ios/12_4t/ip_addr/configuration/guide/htdhcpre.html Prerequisites for Configuring the Cisco IOS DHCP Relay Agent: The Cisco IOS DHCP server and relay agent are enabled by default. You can check whether they have been disabled by looking at your configuration file. If they have been disabled, the no service dhcp command will appear in the configuration file. Use the service dhcp command to reenable the functionality if necessary. https://content.cisco.com/chapter.sjs?uri=/searchable/chapter/content/en/us/td/docs/ios-xml/ios/ipaddr_dhcp/configuration/15-sy/dhcp-15-sy-book/configuring_cisco_ios_dhcp_relay_agent.html.xml

Selected Answer: DE Answer is D and E

Labbed it, and none of the answers worked

there in no ip dhcp relay information enable command. #ip dhcp relay information trusted ?? (config-if)#ip dhcp relay information ? check-reply Validate relay information in BOOTREPLY option DHCP relay information option option-insert Insert relay information in BOOTREQUEST policy-action Define reforwarding policy trusted Received DHCP packet may contain relay info option with zero giaddr (config-if)#ip dhcp relay information trusted

Answer is D and E. B command does not exist. It is assumed that snooping is set for the l2 switch, so E is required on R2.

Selected Answer: DE Option correct D and E https://www.cisco.com/en/US/docs/ios/12_4t/ip_addr/configuration/guide/htdhcpre.html#wp1027171

D and E are correct A doesn't exist B doesn't exist C doesn't exist R2(config)#service dhcp-relay ? % Unrecognized command R2(config)#service dhcp-relay R2(config)#ip dhcp option ? % Unrecognized command R2(config)#ip dhcp option R2(config)#ip dhcp relay information ? check Validate relay information in BOOTREPLY option Insert relay information in BOOTREQUEST policy Define reforwarding policy trust-all Received DHCP packets may contain relay info option with zero giaddr R2(config)#ip dhcp relay information R2(config)#service dhcp R2(config)#

I agree with DE

I did the same, put the configs and enabled dhcp snooping only in the access switch with the uplink port in trust but nothing works, on the core switch I enabled the service dhcp and in the router with dhcp enabled I used the command ip dhcp relay information trust all

the dhcp packets are not relayed from the dhcp relay agent switch, after removing the dhcp snooping in the switch everything is working fine (in the access switch)

ok actually I will go for D and E even if it is not gonna work in the real enviroment. Actually with these commands the relay agent will see that the giaddr field is zero and is not gonna relay nothing even with the command ip dhcp relay information trust-all. What you need to do for solve this issue is just use the command "ip dhcp relay information trusted" in the vlan of the core switch. That command is gonna let the core switch accept the dhcp packet even with giaddr set to zero and is gonna put the ip address of the switch in the giaddr field.