I totally failed to see the relevance of the dhclient here. Option in DHCP have nothing to do with options in hardware specific network card configuration.
Options (255 possible) in dhcp are like either specify in their number or in many cases with their name to make it easy for human, lke 1 -> Subnet 3 -> router 6 -> DNS servers 15 -> domain name 44 -> WINS/NBNS NetBIOS name servers 46 -> Wins/NBT 51 -> Lease time etc. The RFC 2132 is a good source for the full list if you want https://tools.ietf.org/html/rfc2132 But this had nothing to do with options in hardware network cards configuration like half duplex, full duplex, auto negotiation, speed, mtu, etc. I think you may be confusing the OP here by suggesting this. I think if you read the RFC you will see the MTU refereed there is the option code 24 and is not what you think it is. 4.6. Path MTU Aging Timeout Option This option specifies the timeout (in seconds) to use when aging Path MTU values discovered by the mechanism defined in RFC 1191 [12]. The timeout is specified as a 32-bit unsigned integer. Or may be the 4.7 or 5.1 or 5.2, but in all cases it is assuming the MTU discovery actually is enable and work. Nothing to do with the size of the packets. Yes is you have MTU discover enable on your network it will try to find the right size maximum supported, but if you do not have it enable, then you can't fix it via that option and you need to go back and enforce it via the hostname.if Hope this clarify it better. Daniel On 10/3/14 9:35 AM, trondd wrote: > The man page for dhclient.conf shows the ability to ignore options sent by > the dhcp server. If hostname.* doesn't do it, that might be necessary. > > Tim. > > On Fri, Oct 3, 2014 at 4:10 AM, Daniel Ouellet <dan...@presscom.net> wrote: > >> On 10/2/14 11:39 PM, Daniel Ouellet wrote: >>> May be a bit more for you as well under man hostname.if >>> >>> in the description it said this. "Any lines not matching these packed >>> formats are passed directly to ifconfig(8)." >>> >>> and this section. >>> >>> options >>> Miscellaneous options to set on the interface, e.g., "media >>> 100baseTX mediaopt full-duplex". Valid options for a particular >>> interface type can be found in ifconfig(8). When used, the netmask and >>> broadcast_addr options must also be present. >>> >>> Based on this information look to me that you should be able to pass the >>> option you want and it would pass it to ifconfig on your behalf so you >>> should be able to preset your MTU as you see fit there for the network >>> card you specifically want. >>> >>> Anyway the best way would be to try and see what you get. >>> >>> Hopefully this provide you what you need. >>> >>> Daniel >>> >>> >>> >>> On 10/2/14 11:27 PM, Daniel Ouellet wrote: >>>> Unless I do not read the man page properly the information is available >>>> there. >>>> >>>> >>>> NAME >>>> ifconfig -- configure network interface parameters >>>> SYNOPSIS >>>> ifconfig [-AaC] [interface] [address_family] [address >> [dest_address]] >>>> [parameters] >>>> >>>> ... >>>> and lower you have: >>>> ... >>>> The following parameters may be set with ifconfig: >>>> ... >>>> mtu value >>>> Set the MTU for this device to the given value. Cloned routes >>>> inherit this value as a default. For Ethernet devices which support >>>> setting the MTU, a value greater than 1500 enables jumbo frames. The >>>> hardmtu output from hwfeatures shows the maximum supported MTU. >>>> ... >>>> >>>> So if you read the man page you should have the information you need. >>>> >>>> Hope this help >>>> >>>> Daniel
