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  • 1.  DHCP Rely invalid server adresss

    Posted 06-13-2023 10:41

    Good day,

    We have an EX4300 with multiple vlans,

    the "default" vlan is attached to a windows 2012 r2 dhcp server.

    the new vlan (7) has no dhcp server. 

    we want to use dhcp relay to the server.

    forwarding-options {
        dhcp-relay {
            server-group {
                vlan7 {
                    172.17.1.200;  # Windows 2012 R2
                }
            }
            group vlan7{
                active-server-group vlan7;
                interface irb.7;
            }
        }
    }

    when i check "show dhcp relay binding" is see my client "Selecting"

    show dhcp relay statistics 
    Packets dropped:
        Total                      53
        Invalid server address     23
        Interface not configured   30
    
    Messages received:
        BOOTREQUEST                44
        DHCPDECLINE                0
        DHCPDISCOVER               44
        DHCPINFORM                 0
        DHCPRELEASE                0
        DHCPREQUEST                0
        DHCPLEASEACTIVE            0
        DHCPLEASEUNASSIGNED        0
        DHCPLEASEUNKNOWN           0
        DHCPLEASEQUERYDONE         0
        DHCPACTIVELEASEQUERY       0
    
    Messages sent:
        BOOTREPLY                  0
        DHCPOFFER                  0
        DHCPACK                    0
        DHCPNAK                    0
        DHCPFORCERENEW             0
        DHCPLEASEQUERY             0
        DHCPBULKLEASEQUERY         0
        DHCPLEASEACTIVE            0
        DHCPLEASEUNASSIGNED        0
        DHCPLEASEUNKNOWN           0
        DHCPLEASEQUERYDONE         0
        DHCPACTIVELEASEQUERY       0
    
    Packets forwarded:
        Total                      4
        BOOTREQUEST                0
        BOOTREPLY                  4 

    the server is reachable from the ex, can ping it. during setup the ex even received a dhcp adresss from the server native subnet.

    I also tried to run a dhcp scope direcly on the ex4300. this works as expected. 



  • 2.  RE: DHCP Rely invalid server adresss
    Best Answer

    Posted 06-14-2023 07:04

    Can you confirm the vlan configuration for the interface irb.7 since the error message above indicates a potential interface issue.

    And when you do the ping check to the server, specify the source of the ping is the ip address of the interface irb.7 to confirm the forwarding reachability.



    ------------------------------
    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP - Retired)
    http://puluka.com/home
    ------------------------------



  • 3.  RE: DHCP Rely invalid server adresss

    Posted 07-26-2023 03:52

    Sorry for the late reply.

    Was expecting the switch would forward the dhcp requests from its default interface. 

    Everything works as expected as soon as i allowed dhcp requests from vlan 7 to the dhcp server.

    thanks for pointing out the issue.