Hi Phil This does matter because the DHCP server has to answer back to the source address of the packets received and in case you have a firewall between the NET and the DHCP server the firewall could be configured to deny packets from the net.ipB interface and only allow packets from net.IPA.
Finally I have done some tests on the DHCP relay on an M7i (so a real Juniper router) and the behaviour is the same as with Cisco. So the Case that I opened on the JTAC was lastly taken in account as a real bug. I am waiting for a new release now. Yes indeed the problem in the majority of the cases is not very painful but in some cases you can get stuck! Kind regards Alain -----Message d'origine----- De : Phil Mayers [mailto:[email protected]] Envoyé : lundi 9 mars 2009 13:03 À : Briant,A,Alain,JPECS R Cc : [email protected] Objet : Re: [j-nsp] JUNOS BootP-relay Behaviour [email protected] wrote: > When I configure DHCP relay like this on an EX switch: > > "set forwarding-options helpers bootp interface XX server @IPDHCPserver" > > The outgoing relayed paquets are received on the DHCP server with a > source address of the outgoing interface of the EX switch (the Net > IP.B address) > > __________ > _______ { } > Net IP.A | | Net IP.B { } > DHCP client |----------| EX SW |----------{ NET }--| DHCP > server > |_______| { } > {__________} > > > > On a C router and other brands the behaviour is different and the > address used is the one from the incoming interface (the Net IP.A > address) We see this too, but why does it matter? DHCP servers are required to inspect the "giaddr" field in the BOOTP/DHCP header, not the source of the IP packet. _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
