Debugging lease problems with Sun DHCP Servers

While debugging some PXE boot problems a few weeks back, I needed to see who DHCP leases were being issued to. Since the box was running Solaris 9, I was able to take advantage of the Sun DHCP server’s “-d” (debug) and “-v” (verbose) options:

$ /usr/lib/inet/in.dhcpd -d -v -i ge0 -b manual

42a07602:  Daemon Version: 3.5
42a07602:  Maximum relay hops: 4
42a07602:  Run mode is: DHCP Server Mode.
42a07602:  Datastore resource: SUNWfiles
42a07602:  Location: /var/dhcp
42a07602:  DHCP offer TTL: 10
42a07602:  BOOTP compatibility enabled.
42a07602:  ICMP validation timeout: 1000 milliseconds, Attempts: 1.
42a07602:  Maximum concurrent clients: 1024
42a07602:  Maximum threads: 256
42a07602:  Read 4 entries from DHCP macro database on Fri Jun  3 11:23:46 2005
42a07602:  Monitor (0003/ge0) started...
42a07602:  Thread Id: 0003 - Monitoring Interface: ge0 *****
42a07602:  MTU: 1500    Type: SOCKET
42a07602:  Broadcast: 10.10.10.255
42a07602:  Netmask: 255.255.255.0
42a07602:  Address: 10.10.10.122
42a07632:  Datagram received on network device: ge0(limited broadcast)
42a07632: (Error 0) No more IP addresses on 10.10.10.0 network
42a07637:  Datagram received on network device: ge0(limited broadcast)
42a07637: (Error 0) No more IP addresses on 10.10.10.0 network
42a0763f:  Datagram received on network device: ge0(limited broadcast)
42a0763f: (Error 0) No more IP addresses on 10.10.10.0 network
42a0764f:  Datagram received on network device: ge0(limited broadcast)
42a0764f: (Error 0) No more IP addresses on 10.10.10.0 network
42a07663:  Datagram received on network device: ge0(limited broadcast)
42a07664:  Sending datagram to broadcast address.
42a07664:  (Added offer: 10.10.10.112
42a0766b:  Datagram received on network device: ge0(limited broadcast)
42a0766b:  Client: 01000D609C8889 maps to IP: 10.10.10.112
42a0766b:  Sending datagram to broadcast address.
42a0766e:  Datagram received on network device: ge0(limited broadcast)
42a0766e:  Unicasting datagram to 10.10.10.112 address.
42a0766e:  Adding ARP entry: 10.10.10.112 == 000D609C8889
42a0766e:  Updated offer: 10.10.10.112
42a0766e:  Datagram received on network device: ge0(limited broadcast)
42a0766e:  Reserved offer: 10.10.10.112
42a0766e:  Database write unnecessary for DHCP client: 01000D609C8889, 10.10.10.112
42a0766e:  Client: 01000D609C8889 maps to IP: 10.10.10.112
42a0766e:  Unicasting datagram to 10.10.10.112 address.
42a0766e:  Adding ARP entry: 10.10.10.112 == 000D609C8889

The debug option will place the DHCP server into the foreground, causing the server to print a slew of information to the terminal screen. The debug options helped me solve my problem, and assisted with identifying several devices that shouldn’t be using DHCP.

1 thought on “Debugging lease problems with Sun DHCP Servers”

  1. Hi
    I am trying to jumpstart a client, SUNBLADE 2500 with solaris. Do you know how to modify the TTL 1 on a rarp packet, so it could traverse a router and reach the jumpstart server which is in another subnet. Obviously I cannot use another SUN workstation as bootp server.

    Thank you

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