I don' t understand how packets are thrown between interfaces with IP forwarding off. Maybe nevertheless there is 0.0.0.0 binding.
вт, 5 сент. 2023 г. в 15:10, CpServiceSPb <cpservice...@gmail.com>: > As you added the functionality, can you send this version ? > I will test as well on my own. > > > вт, 5 сент. 2023 г. в 13:54, Miroslav Lichvar <mlich...@redhat.com>: > >> On Thu, Aug 31, 2023 at 12:06:35AM +0300, CpServiceSPb wrote: >> > I may be wrong but as I understand that binding to an address is almost >> the >> > same as binding to an interface. >> >> I think those are two different things. In chrony there is the >> binddevice directive for binding to a device. It can be used only once >> for the same reasons as bindaddress. >> >> > Maybe I am wrong, again. >> > And it is meaning that an appropriate opened socket will receive packers >> > only from the corresponding interface, of course if IP forwarding, >> source >> > nat and so on is not set up. >> >> I ran a test. I started the server with 'bindaddress 192.168.50.2' and >> checked tcpdump output on the other interface, which has network >> 192.168.70.0/24 and no other routes. >> >> 10:46:41.686783 IP 192.168.70.1.53545 > 192.168.50.2.ntp: NTPv4, Client, >> length 48 >> 10:46:41.686863 IP 192.168.50.2.ntp > 192.168.70.1.53545: NTPv4, Server, >> length 48 >> >> It is happily responding to clients sending to the bound address, even >> if it's a different interface. IP forwarding is disabled. There is no >> NAT. The rp_filter setting doesn't seem to affect this. I think it's >> supposed to check only the source address. >> >> > So, it can be checked practically. >> > Is it true or false. >> > When you will add such functionality, I will build a new version of >> chrony >> > and will turn off nat, ip forwarding and will launch tcpdump and will >> see >> > what happens on the lan interface when some client from dmz sends a >> request >> > to dmz interface. >> > That is, will any packets come to the lan interface or not. >> >> You can verify that with single bindaddress. >> >> If you really need multiple addresses, you can start multiple servers >> instances as explained here: >> >> https://chrony-project.org/faq.html#_can_ntp_server_be_separated_from_ntp_client >> >> -- >> Miroslav Lichvar >> >> >> -- >> To unsubscribe email chrony-dev-requ...@chrony.tuxfamily.org with >> "unsubscribe" in the subject. >> For help email chrony-dev-requ...@chrony.tuxfamily.org with "help" in >> the subject. >> Trouble? Email listmas...@chrony.tuxfamily.org. >> >>
