Switching

Hi 

I 've configured DHCP relay on EX4300 but DHCP message is not be forwarded to DHCP server. 

Here is my configuration.

set forwarding-options dhcp-relay server-group CP 10.1.2.99
set forwarding-options dhcp-relay server-group CP 10.1.3.254
set forwarding-options dhcp-relay active-server-group CP
set forwarding-options dhcp-relay group server active-server-group CP
set forwarding-options dhcp-relay group server interface irb.27 < VLAN27 = Client' vlan

root# run show dhcp relay statistics
Packets dropped:
Total 0

Messages received:
BOOTREQUEST 309
DHCPDECLINE 0
DHCPDISCOVER 309
DHCPINFORM 0
DHCPRELEASE 0
DHCPREQUEST 0
DHCPLEASEACTIVE 0
DHCPLEASEUNASSIGNED 0
DHCPLEASEUNKNOWN 0
DHCPLEASEQUERYDONE 0

Messages sent:
BOOTREPLY 0
DHCPOFFER 0
DHCPACK 0
DHCPNAK 0
DHCPFORCERENEW 0
DHCPLEASEQUERY 0
DHCPBULKLEASEQUERY 0

Hello,

Please check Your lo0.0 filter to allow udp ports 67,68 

Thanks

Alex

 Hi Halo,

Also, we can check  this output to see the BOOTP requests sent out to server and BOOTP replies received:

monitor traffic interface <egress_interface_towards_server> no-resolve extensive

In some cases, if the server responds with a non-standard source-port (anything other than udp 67), BOOTP replies will be dropped.  And you may need to enable this knob (available from Junos 14.1X53-D12.4 or 14.1X53-D30 and above)
set system processes dhcp-service accept-any-source-port

Hope this helps.

Regards,
-r.

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There's no frewall filter on lo0.0. Interface irb.27 can ping to DHCP server.

I saw this message when I capture packet on egress

Hi Halo,

Please note that the command to capture packets on egress is:

monitor traffic interface <egress_interface_towards_server> no-resolve extensive

The knob that to accept any source that we were looking at, is hidden, so please continue typing it in and commit:

set system processes dhcp-service accept-any-source-port

See https://prsearch.juniper.net/InfoCenter/index?page=prcontent&id=PR1070989 

Hope this helps.

Regards,
-r.

--------------------------------------------------

If this solves your problem, please mark this post as "Accepted Solution."
Kudos are always appreciated :).

Hey,

check if dhcp server is reacbable from irb.27 with source ping.