DHCP Relay Configuration on Cisco ASR 9000

[ybhanscs]

I have a trouble when configuring DHCP Relay on Cisco ASR 9000. I've followed the configuration guide on www.cisco.com/c/en/us/td/docs/routers/crs/software/crs_r4-2/addr_serv/configuration/guide/b_ipaddr_cg42crs/b_ipaddr_cg42crs_chapter_0100.html . I think my server configuration is right, but still can't get IP on my host. Here is my topology and my recent configuration. Thank in advance.

[Evgeniy Prichinin]

Your configuration on interfaces should contain vrf TA_DHCP or ip helper address vrf global. Because you main interfaces don't belong to vrf, but you try to forward packets to VRF.

btw. you don't need a ip helper address on interface to dhcp server. 

[ybhanscs]

vrf is a little bit confusing me. can I just apply helper address on the interface? just like usual cisco config? btw, I have tried it before, but it seems the router couldn't save my commit.

[Evgeniy Prichinin]

as i remember ip helper-address <ip> will be replaced with ip helper-address vrf default <ip> by router itself.

[ybhanscs]

It's not global but default in here. can you tell me how to add interface to vrf?

btw, address in "helper-address [vrf vrf- name ] address " refers to DHCP server address ? 

[Evgeniy Prichinin]

int gi0/0/0/1 

no ipv4 addr 

vrf <VRF_NAME>

ipv4 addr 22.22.22.2/24

int gi0/0/0/11

no ipv4 addr

vrf <VRF_NAME>

ipv4 addr 33.33.33.1/24

ipv4 helper-address vrf <VRF_NAME> <DHCP_IP>

don't forget about static route to 33.33.33.0/24 via 22.22.22.2 or default route on dhcp server. 

[ybhanscs]

I changed my vrf name to dhcp1, and still not working. Here are my configuration:

int gi0/0/0/1 

no ipv4 addr 

vrf dhcp1

ipv4 addr 22.22.22.2/24

int gi0/0/0/11

no ipv4 addr

vrf dhcp1

ipv4 addr 33.33.33.1/24

ipv4 helper-address vrf dhcp1 22.22.22.1

I've tried setting all the IP static and the server still can't ping to client. And I've added ip route on the server btw.

[Evgeniy Prichinin]

Can server ping its default gw ? 

[ybhanscs]

Three days ago it can, but now it can't. I don't know why, but it's maybr a hardware problem. So, if the server can ping its gateway, what is probably wrong?

[Evgeniy Prichinin]

something wrong with cabling or layer 2 issue.