booting rtems over the network?

Jack Cawkwell J.Cawkwell at
Sat Jun 15 10:23:02 UTC 2002


Thanks for the suggestion, but I am not sure where the
DHCP configuration file is? I have a /etc/xinetd.d/bootps
file which sets up the bootpd, and a /etc/bootptab which
maps MAC addresses to IP address and boot images.

I thought 1500 was pretty standard as a packet size, but
maybe not for a low level communication like this.

Does anyone have similar debugging output for a working
bootpd, this is my /etc/xinetd.d/bootps contents:

service bootps
        server          = /usr/sbin/bootpd
        server_args     = -d 6
        id              = bootp-dgram
        socket_type     = dgram
        protocol        = udp
        user            = root
        wait            = yes

and /etc/bootptab:


Cheers, Jack
cjohns at writes:
>Jack Cawkwell wrote:
>> Thanks for that Ian, ifconfig tells me that the MTU is 1500.
>> so I guess that is not the problem?
>> >>
>> >>Searching for server (DHCP)...
>> >>ALERT: got a fragmented packet reconfigure your server
>> >>
>> >>at the server:
>> >>
>> >>bootpd[30134]: bootptab mtime: Sun Jun  9 11:56:48 2002
>> >>bootpd[30134]: request from Ethernet address 00:D0:09:F1:E3:C1
>> >>bootpd[30134]: found (pablo)
>> >>bootpd[30134]: bootfile="/tftpboot/picodemo8.nbi"
>> >>bootpd[30134]: vendor magic field is
>> >>bootpd[30134]: request message length=548
>> >>bootpd[30134]: request has DHCP msglen=1500
>> >>bootpd[30134]: extended reply, length=1500, options=1264
>                                    ^^^^^^^^^
>This seems rather large for DHCP. I suggest you check your DHCP
>configuration file and see if you can make the message smaller.
>> >>
>> >>ALERT: got a fragmented packet reconfigure your server
>> >>
>A 1500 byte message will be fragmented as the MAC and networking layers
>take some of the MTU space.
> Chris Johns, cjohns at

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