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  • 1.  DHCP on vJunos-router lab not responding with Offers

    Posted 14 days ago
    Edited by Jodi Meier 14 days ago

    Just starting into learning Juniper. 
    vJunos-router Version 23.4R2-S2.1

    Getting stumped by something seemingly simple. 
    Followed this guide for minimal configuration
    The vJunos device just wont respond with DHCP Offers to requests
    1 "PC" in GNS3 attached directly to interface ge-0/0/1 on the vJunos-router KVM.

    Current Commit

    root# show 
    ## Last changed: 2025-01-23 06:41:57 UTC
    version 23.4R2-S2.1;
    system {
        root-authentication {
            encrypted-password "Redacted"; ## SECRET-DATA
        }
        services {
                group GNS3GRP {
                    interface ge-0/0/1.0;
                }
            }
        }
        syslog {
            file interactive-commands {
                interactive-commands any;
            }
            file messages {
                any notice;                 
                authorization info;
            }
        }
        processes {
            dhcp-service {
                traceoptions {
                    file dhcp_logfile size 10m;
                    level all;
                    flag packet;
                }
            }
        }
    }
    interfaces {
        ge-0/0/1 {
            unit 0 {
                family inet {
                    address 192.168.150.1/24;
                }
            }
        }
        fxp0 {
            unit 0 {                        
                family inet {
                    dhcp {
                        vendor-id Juniper-vmx-VM6790FD5F7C;
                    }
                }
                family inet6 {
                    dhcpv6-client {
                        client-type stateful;
                        client-ia-type ia-na;
                        client-identifier duid-type duid-ll;
                        vendor-id Juniper:vmx:VM6790FD5F7C;
                    }
                }
            }
        }
    }
    access {
        address-assignment {
            pool GNS3LAB {
                family inet {
                    network 192.168.150.0/24;
                    range R1 {
                        low 192.168.150.10; 
                        high 192.168.150.20;
                    }
                }
            }
        }
    }
    protocols {
        router-advertisement {
            interface fxp0.0 {
                managed-configuration;
            }
        }
    }
    
    [edit]
    root# 
    

    Output of dhcpd_log monitor when device attached to ge-0/0/1.0 sends a DHCP Discover request

    root# Jan 23 14:06:11.741501 [MSTR][DEBUG] jdhcpd_packet_info_new: PACKET - Allocated new v4 packet 0x4cb7390
    Jan 23 14:06:11.742138 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP   from == 0.0.0.0, port == 68 ]--
    Jan 23 14:06:11.742147 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP   size == 364, op == 1 ]--
    Jan 23 14:06:11.742161 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP  flags == 0 ]--
    Jan 23 14:06:11.742168 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP  htype == 1, hlen == 6 ]--
    Jan 23 14:06:11.742176 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP   hops == 0, xid == 8e4e886e ]--
    Jan 23 14:06:11.742181 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP   secs == 0, flags == 0000 ]--
    Jan 23 14:06:11.742195 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP ciaddr == 0.0.0.0 ]--
    Jan 23 14:06:11.742210 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP yiaddr == 0.0.0.0 ]--
    Jan 23 14:06:11.742217 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP siaddr == 0.0.0.0 ]--
    Jan 23 14:06:11.742225 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP giaddr == 0.0.0.0 ]--
    Jan 23 14:06:11.742237 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP chaddr == 00 50 79 66 68 00 00 00 00 00 00 00 00 00 00 00 ]--
    Jan 23 14:06:11.742248 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP  sname ==  ]--
    Jan 23 14:06:11.742254 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ DHCP/BOOTP   file ==  ]--
    Jan 23 14:06:11.742274 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ OPTION code  53, len   1, data DHCP-DISCOVER ]--
    Jan 23 14:06:11.742286 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ OPTION code  12, len   3, data 50 43 31 ]--
    Jan 23 14:06:11.742293 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] --[ OPTION code  61, len   7, data 01 00 50 79 66 68 00 ]--
    Jan 23 14:06:11.742299 [MSTR][INFO] [default:default][SVR][INET][ge-0/0/1.0] --[ OPTION code 255, len   0 ]--
    Jan 23 14:06:11.742328 [MSTR][INFO]  jdhcpd_is_alq_topology_discover_configured: Topology discover not configured for server. default.default
    
    Jan 23 14:06:11.742424 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] jdhcpd_find_client_from_client_pdu: BOOTPREQUEST could not find client table ent
    Jan 23 14:06:11.742627 [MSTR][DEBUG] jdhcpd_packet_map_to_wholesale_client: No wholesale clients moved out routing instance default:default
    Jan 23 14:06:11.742635 [MSTR][DEBUG] jdhcpd_packet_map_to_wholesale_client: Client entry NOT found
    Jan 23 14:06:11.742643 [MSTR][NOTE]  jdhcpd_packet_handle: RECEIVE DISCOVER: stats_safd 0x0 , safd 0x4cc0700 ge-0/0/1.0
    Jan 23 14:06:11.743028 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] jdhcpd_process_forward_only_or_drop: Returning ... forward-only flags not set (flags=deaddead, rc_flags 8a4480d) for routing context 0
    Jan 23 14:06:11.743211 [MSTR][DEBUG][default:default][SVR][INET][SID=0] jdhcpd_packet_handle: new client table entry created for ifindex 342
    Jan 23 14:06:11.743225 [MSTR][DEBUG][default:default][SVR][INET][ge-0/0/1.0] jdhcpd_process_offer_advertise_delay: Returning ... offer delay not set (flags=3, rc_flags 8a4480d) for routing context 0, rc(4dfb000)
    Jan 23 14:06:11.743252 [MSTR][DEBUG][default:default][SVR][INET][SID=0] jdhcpd_packet_handle: Set client next-hop mac addr:  00 50 79 66 68 00 state(0)
    Jan 23 14:06:11.743296 [MSTR][INFO]  jdhcpd_client_set_pkt: *********** Setting v4 packet 0x4cb7390
    Jan 23 14:06:11.748128 [MSTR][INFO]  jdhcpd_client_unset_pkt: ***********  Unsetting v4 packet 0x4cb7390
    Jan 23 14:06:11.748321 [MSTR][WARN]  jdhcpd_packet_free: freeing packet 0x4cb7390
    

    The lines in here that caught my attention the most is 742627 and 743028 - Not that I exactly understand them, but they seemed more telling as to what's potentially wrong than the rest - not that I know what to do with them.

    It's a silly little problem and I don't feel like I really need it 'solved' to move on with learning more about Junos - It's just been bugging me for a few days.

    Thanks!



    ------------------------------
    Quinn Bowman
    ------------------------------



  • 2.  RE: DHCP on vJunos-router lab not responding with Offers
    Best Answer

    Posted 13 days ago

    I think you are probably missing something like:

    set system services dhcp-local-server group blah interface ge-0/0/1.0

    I'm not sure what the system processes does, but I'm pretty sure it isn't setting up a dhcp server.

    Juniper's documentation is always a bit word heavy and information light, but you could look here - https://www.juniper.net/documentation/us/en/software/junos/dhcp/topics/topic-map/dhcp-server-configuration.html

    M




  • 3.  RE: DHCP on vJunos-router lab not responding with Offers

    Posted 12 days ago

    Oh that's strange....that line is absolutely in my actual config...I wonder if when the Forum automatically stripped out encrypted password line it took some more with it. Weird.
    Anyway, yea, thanks for linking that doc, that's the one I followed to try this 'minimal' configuration setup. No Dice.
    Somebody on another forum is suggesting that it's a licensing thing, since the vJunos-router build is based on the MX line, which requires a license for DHCP.
    Anyway, thanks for your time!



    ------------------------------
    Quinn Bowman
    ------------------------------