Hello list, please CC me in replies to this mail, since I am no subscriber to this list.
For safety reasons, we enclose user input to shell commands in quotes. Until today, the resulting command for ifconfig(8) looked like this: > ifconfig ue0 inet "192.168.2.176 netmask 255.255.255.0" As we figured out, this means that ifconfig sometimes doesn't set the netmask as we expect it to do: > root@csbuild:~ # ifconfig ue0 > ue0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 > options=80001<RXCSUM,LINKSTATE> > ether b8:27:eb:fd:58:69 > inet 192.168.2.176 netmask 0xffff0000 broadcast 192.168.255.255 > media: Ethernet autoselect (100baseTX <full-duplex>) > status: active > nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL> > root@csbuild:~ # ifconfig ue0 inet "192.168.2.176 netmask 255.0.0.0" > root@csbuild:~ # echo $? > 0 > root@csbuild:~ # ifconfig ue0 > ue0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 > options=80001<RXCSUM,LINKSTATE> > ether b8:27:eb:fd:58:69 > inet 192.168.2.176 netmask 0xffffff00 broadcast 192.168.2.255 > media: Ethernet autoselect (100baseTX <full-duplex>) > status: active > nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL> > root@csbuild:~ # As you can see, ifconfig sets the netmask to 255.255.255.0, ignoring the netmask we provided. If provided with a 10.* address, ifconfig sets the netmask to 255.0.0.0, no matter what actual netmask we entered. Also, it doesn't exit with a status indicating error, which made it a little harder to debug this issue. The following works as expected: > root@csbuild:~ # ifconfig ue0 > ue0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 > options=80001<RXCSUM,LINKSTATE> > ether b8:27:eb:fd:58:69 > inet 192.168.2.176 netmask 0xffffff00 broadcast 192.168.2.255 > media: Ethernet autoselect (100baseTX <full-duplex>) > status: active > nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL> > root@csbuild:~ # ifconfig ue0 inet "192.168.2.176" netmask "255.0.0.0" > root@csbuild:~ # ifconfig ue0 > ue0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 > options=80001<RXCSUM,LINKSTATE> > ether b8:27:eb:fd:58:69 > inet 192.168.2.176 netmask 0xff000000 broadcast 192.255.255.255 > media: Ethernet autoselect (100baseTX <full-duplex>) > status: active > nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL> > root@csbuild:~ # What exactly does ifconfig do? It seems to me that it reads the IP address from the quoted string but truncates the netmask. Is this a bug in ifconfig or intended behavior? Best wishes Jeremy _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
