"Supersede" gives me what I want. It just felt weird those entries ended up on resolv.conf when I had not requested them.
Thanks and sorry for the noise. 2011/8/27 IC1igo Ortiz de Urbina <[email protected]>: > Hi all users and developers > > I simply noticed what I would call a weird behaviour on my 32 bit 4.9 > GENERIC#671 box's dhclient, which I hope is not the expected behavior. > While reading RFC2131, I didnt find any sentence stating or implying > that is the desired behavior, as in a "server MUST...". > > Say I run a local instance of named on my machine. I dont want dhcp to > overwrite my resolv.conf, so I add the classical prepend > dns-name-servers to my dhclient.conf. > > I capture the traffic while asking for an IP address (no prior leases) > and I can see how DHCP packets do not request DNS servers. However, > which I am afraid happens more often than not, my crappy Comtrend > domestic router ignores the request and simply decides to always > answer including my ISPs DNS servers. I could check this with > Wireshark also. The result is resolv.conf has 3 nameserver entries, > instead of the only one I want to prepend. > > I also tried not prepending my localhost named entry, just in case > that would trigger something weird in the code and eventually > nameservers got appended. No luck. > > dhclient.conf(5) states the following: > > "The protocol also allows the client to reject offers > B B from servers if they don't contain information the client needs, or if > B B the information provided is not satisfactory." > > So, shouldnt dhclients just keep track of what they requested and just > accept that specific set of properties, instead of all it was sent by > the router? I am not talking about whether RFCs or the implementation > is correct or not. I am no authority of course. It simply seems > reasonable to me to implement it as I just mentioned. I understand > clients can ask for parameters that would lead to an invalid network > configurations. Still, Unix doesnt let you shoot yourself in the foot > for a good reason? Am I missing the obvious? > > Any comment would be highly appreciated. > > Thanks for your time and have a nice day > > -- IC1igo Ortiz de Urbina Cazenave http://www.twitter.com/ioc32
