Re: can't add a /24 blackhole route with a /32 loopback

Here is the ifconfig for loopbacks:

```
 ifconfig lo1
lo1: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
	options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
	inet6 fe80::1%lo1 prefixlen 64 scopeid 0x9
	inet6 XXXX:XXXX:1:1::1 prefixlen 128
	inet 1.1.1.1 netmask 0xffffffff
	groups: lo
	nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
root@core0:~ # ifconfig lo0
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
	options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
	inet6 ::1 prefixlen 128
	inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3
	groups: lo
	nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>

```

Hope this helps,


Benoît

------- Original Message -------
On Wednesday, June 14th, 2023 at 11:42, Alexander Chernikov <melifaro@FreeBSD.org> wrote:


> > On 14 Jun 2023, at 10:06, Benoit Chesneau benoitc@enki-multimedia.eu wrote:
> > 
> > I forgot oto add the error message , sorry.
> > 
> > When I try to set the theblackhole flag I get the following error:
> > 
> > `route: writing to routing socket: Operation not supported change net 1.1.1.0 fib 0: Operation not supported`
> 
> Interesting. Could you also share full ifconfig output or at least ifconfig for each of the loopbacks?
> If the output contains something you’re not comfortable sharing in the ML, you could consider sending it directly to my email.
> 
> > ------- Original Message -------
> > On Wednesday, June 14th, 2023 at 10:38, Benoit Chesneau benoitc@enki-multimedia.eu wrote:
> > 
> > > Hi,
> > > 
> > > Thanks for your answer. I'm using Freebsd 13.2 latest version:
> > > 
> > > $ uname -srm
> > > FreeBSD 13.2-RELEASE amd64
> > > 
> > > I edited the filtred result of the table since it has a full view:
> > > 
> > > netstat -4rnW |grep -e "1.1.1"
> > > 1.1.1.0/24 127.0.0.1 USB 14 16384 lo0
> > > 1.1.1.1 link#9 UHS 26 16384 lo1
> > > 1.1.1.2 10.3.1.1 UGH1 15 9000 vlan2212
> > > 1.1.1.2 10.3.1.1 UGHS 16 1500 vlan2212
> > > 1.1.1.2 10.3.1.1 UGHS 25 9000 vlan2212
> > > 
> > > Also I forgot to mention that the ethernet driver is MLX4EN(4):
> > > 
> > > mlx4_core0@pci0:8:0:0: class=0x028000 rev=0x00 hdr=0x00 vendor=0x15b3 device=0x1007 subvendor=0x103c subdevice=0x22f3
> > > vendor = 'Mellanox Technologies'
> > > device = 'MT27520 Family [ConnectX-3 Pro]'
> > > class = network
> > > Corrected = Advisory Non-Fatal Error
> > > 
> > > Hope it helps,
> > > 
> > > Benoît
> > > ------- Original Message -------
> > > On Wednesday, June 14th, 2023 at 10:29, Alexander Chernikov melifaro@FreeBSD.org wrote:
> > > 
> > > > > On 14 Jun 2023, at 07:05, Benoit Chesneau benoitc@enki-multimedia.eu wrote:
> > > > > 
> > > > > Hi,
> > > > > 
> > > > > When I setup a loopback to a /32 , I can add a /24 as a blackhole route anymore. I can only create a /24 attached to this looopback. Ie.
> > > > 
> > > > Could you add a bit more context?
> > > > What is the FreeBSD version (uname -srm)?
> > > > What does 'route add 1.1.1.0/24 -blackhole’ show?
> > > > Could you also share netstat -4rnW and ifconfig output (maybe privately)?
> > > > 
> > > > > when `lo1` is set to `1.1.1.1/32` I cant create a blackhole route to `1.1.1.0/24` using the command : `route add 1.1.1.0/24 -blackhole` . Is there any reason for it? The idea is to be able to advertise the prefix `1.1.1.0/24` via BGP (bird) and use 1.1.1.1/32` as a loopback distributed to other nodes using OSPF. I can probably make the loopback a /24 used by bird but what would be the other way to do it?
> > > > > 
> > > > > Benoît