kwesterb...@gmail.com (Kenneth Westerback), 2014.06.23 (Mon) 18:53 (CEST): > On 23 June 2014 06:24, Avi Cohen <av...@rad.com> wrote: > > In my application (it is a router in the access) I'm initially running > > dhclient daemon without any interface specified for dhcp. > > Then - on user request - we add interfaces to dhclient.conf on run-time > > > > I have 3 questions - that I'll appreciate if you can answer > > You can read dhclient(8) and dhclient.conf(5) man pages for details. > But to summarize ... > > (You seem to ask 4 questions, so which one will you not appreciate an > answer to? :-)) > > > > > 1. Is it possible to append interfaces to an existing dhclient.conf > > ? > > or just to add a new (for example) dhclient.conf-eth1? [BTW - where to > > locate this file ?] > > You can append as many 'interface' statements as you like in the > dhclient.conf file. If you want to run with a separate config file for > a particular instance of dhclient you can use the '-c' option to > specify the non-default file. > > > > > 2. When the daemon will start the dhcp-request for this new > > interface > > ? > > When you start it. Every interface's dhclient must be started > separately. If you start a dhclient without specifying the interface > it attempts to find an interface in the 'egress' group. If there is > one and only one such interface then dhclient will use it. For other > interfaces you must start other instances of dhclient, usually by > creating a /etc/hostname.<if> file for that interface. The > /etc/hostname.<if> file will be used at system startup or you can 'sh > /etc/netstart <if>' as root. > > > 3. Our application need to be informed whenever a new IP-address > > (dhcp) > > is assigned for the interface. How to do it ? by polling the > > dhclient.leases > > ? is there a notification from dhclient to our application that we can use > > ? > > The best way to do that is with a program that monitors the routing > socket, where you can see all address changes.
hint: route(8) monitor Bye, Marcus > Alternatively you can monitor the leases file or use the '-L' option > to write out the offered and effective lease information if you want > complete information on what is being received and used. Some people > use the entr port (/usr/ports/sysutils/entr, http://entrproject.org/) > to monitor the file(s). > > > > > 4. 4 - if I start the dhclient daemon without interface specified - I > > see that it sends dhcp-request for all my exiting interfaces ? why ? how to > > disable this behavior and to send request for only > > > > Specified interfaces ? (but without specifying it in the command line- but > > via dhclient.conf ? > > Now you make me doubt you are running OpenBSD. Our dhclient does not > send dhcp-request for all interfaces -- it sends dhcp-requests out one > and only one interface. At least for the last 10 years or more. > > You must specify the interface via the command line, or have the > /etc/netstart command build the command line for you from a > hostname.<if> file. > > .... Ken > > > Regards, > > Avi > > !DSPAM:53a85bed101242941456129!
