[FROG] disc0 interface in FreeBSD 12.x
Stephen Worley
sworley at cumulusnetworks.com
Thu Oct 1 19:10:47 UTC 2020
yea i will bring the issue up in our community about why bother to keep the
config.
On Thu, Oct 1, 2020 at 3:03 PM mike tancsa <mike at sentex.net> wrote:
> On 10/1/2020 2:45 PM, Stephen Worley wrote:
> > Can you not just blackhole it? `ip route *****/* blackhole`
>
> Seems to work yes. One thing lost this way is I can no longer track
> traffic destined for the disc0 interface via snmp as the ip route
> x.x.x.x/x blackhole ties it to lo0 in the kernel. Not a big deal
> however. Frankly, it was just the way I had been doing it since
> probably ISDN :)
>
> >
> > As to why its allowed into the config... i'm not sure, it seems that
> > was intentionally allowed according to the patch.
>
> Seems like it would just be better to not allow it if its not supposed
> to work.
>
> Thanks,
>
> ---Mike
>
>
> >
> > On Thu, Oct 1, 2020 at 11:41 AM mike tancsa <mike at sentex.net
> > <mailto:mike at sentex.net>> wrote:
> >
> > What is the preferred syntax going forward ? I just want to tie down
> > larger prefixes to the discard interface so any packets sent to dead
> > space just get discarded. I dont want icmp messages sent back.
> >
> > ip route 10.0.0.0/8 <http://10.0.0.0/8> disc0 ?
> >
> > Also, if the old syntax is not going to work, perhaps not allow it in
> > the config ?
> >
> > ---Mike
> >
> > On 10/1/2020 11:31 AM, Stephen Worley wrote:
> > > this was disallowed starting
> > > with https://github.com/FRRouting/frr/pull/4302
> > >
> > > If you have a valid use case might be worth discussing with the
> > author
> > > over slack.
> > >
> > > On Thu, Oct 1, 2020 at 9:33 AM mike tancsa <mike at sentex.net
> > <mailto:mike at sentex.net>
> > > <mailto:mike at sentex.net <mailto:mike at sentex.net>>> wrote:
> > >
> > > Hi Donald, the 10.128.128.144 is the disc0 interface on my
> > production
> > > router running frr6 and it works as expected. I setup
> > another test box
> > > with frr6 and used the same disc0 ip config
> > >
> > >
> > > e.g. on frr6
> > >
> > > # ifconfig disc0
> > > disc0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0
> > mtu 65532
> > > inet 10.128.128.1 netmask 0xfffffffc
> > > groups: disc
> > > nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
> > >
> > > frr6# sh ip route connected
> > > Codes: K - kernel route, C - connected, S - static, R - RIP,
> > > O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
> > > T - Table, v - VNC, V - VNC-Direct, A - Babel, D -
> SHARP,
> > > F - PBR,
> > > > - selected route, * - FIB route
> > >
> > > C>* 10.128.128.0/30 <http://10.128.128.0/30>
> > <http://10.128.128.0/30> is directly
> > > connected, disc0, 00:00:19
> > >
> > > frr6# sh ip route 10.128.128.1
> > > Routing entry for 10.128.128.0/30 <http://10.128.128.0/30>
> > <http://10.128.128.0/30>
> > > Known via "connected", distance 0, metric 1, best
> > > Last update 00:00:42 ago
> > > * directly connected, disc0
> > >
> > > frr6# conf t
> > > frr6(config)# ip route 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8> 10.128.128.1
> > > frr6(config)# ^Z
> > > frr6# sh ip route 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8>
> > > Routing entry for 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8>
> > > Known via "static", distance 1, metric 0, best
> > > Last update 00:00:06 ago
> > > * 10.128.128.1, via disc0
> > >
> > > frr6#
> > >
> > >
> > > on frr7
> > >
> > > frr7# sh ip route connected
> > > Codes: K - kernel route, C - connected, S - static, R - RIP,
> > > O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
> > > T - Table, v - VNC, V - VNC-Direct, A - Babel, D -
> SHARP,
> > > F - PBR, f - OpenFabric,
> > > > - selected route, * - FIB route, q - queued route, r -
> > > rejected
> > > route
> > >
> > > C>* 10.128.128.0/30 <http://10.128.128.0/30>
> > <http://10.128.128.0/30> [0/1] is directly
> > > connected, disc0, 00:24:49
> > >
> > > frr7# sh ip route 10.128.128.1
> > > Routing entry for 10.128.128.0/30 <http://10.128.128.0/30>
> > <http://10.128.128.0/30>
> > > Known via "connected", distance 0, metric 1, best
> > > Last update 00:25:07 ago
> > > * directly connected, disc0
> > >
> > > frr7# conf t
> > > frr7(config)# ip route 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8> 10.128.128.1
> > > % Warning!! Local connected address is configured as Gateway
> > > IP(10.128.128.1)
> > >
> > > frr7# sh ip route 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8>
> > > % Network not in table
> > > frr7#
> > >
> > > ---Mike
> > >
> > >
> > >
> > > On 10/1/2020 8:00 AM, Donald Sharp wrote:
> > > > Can we see the output of `show ip route 10.128.128.144`
> > and `show ip
> > > > route connected`?
> > > >
> > > > donald
> > > >
> > > > On Wed, Sep 30, 2020 at 3:03 PM mike tancsa
> > <mike at sentex.net <mailto:mike at sentex.net>
> > > <mailto:mike at sentex.net <mailto:mike at sentex.net>>> wrote:
> > > >> Up to version 6.x of frr, I have been able to tie down
> larger
> > > prefixes
> > > >> with a static routing pointing to the discard interface
> > on FreeBSD.
> > > >>
> > > >> eg. the static route entry
> > > >>
> > > >> ip route 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8> 10.128.128.144
> > > >>
> > > >> # sh ip route 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8>
> > > >> Routing entry for 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8>
> > > >> Known via "static", distance 1, metric 0, best
> > > >> Last update 09w0d01h ago
> > > >> * 10.128.128.144, via disc0
> > > >>
> > > >> where disc0 is
> > > >>
> > > >> # ifconfig disc0
> > > >> disc0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0
> > mtu 65532
> > > >> inet 10.128.128.144 netmask 0xfffffffc
> > > >> inet6 fe80::1%disc0 prefixlen 64 scopeid 0x8
> > > >> inet6 2001:db8::1 prefixlen 64
> > > >> groups: disc
> > > >> nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
> > > >>
> > > >>
> > > >> however, on frr7.4 this no longer works,
> > > >>
> > > >> On my test box
> > > >>
> > > >> % ifconfig disc0
> > > >> disc0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0
> > mtu 65532
> > > >> inet 10.128.128.1 netmask 0xfffffffc
> > > >> inet6 fe80::1%disc0 prefixlen 64 scopeid 0x6
> > > >> groups: disc
> > > >> nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
> > > >>
> > > >>
> > > >>
> > > >> i3# conf t
> > > >> i3(config)# ip route 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8> 10.128.128.1
> > > >> % Warning!! Local connected address is configured as Gateway
> > > >> IP(10.128.128.1)
> > > >> i3(config)#
> > > >>
> > > >> i3# sh ip route 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8>
> > > >> % Network not in table
> > > >> i3#
> > > >>
> > > >> If I user disc0, it seems to work, but I get warnings on
> > start up
> > > >>
> > > >> i3(config)# ip route 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8> disc0
> > > >>
> > > >> i3# wr
> > > >> Note: this version of vtysh never writes vtysh.conf
> > > >> Building Configuration...
> > > >> Configuration saved to /usr/local/etc/frr/zebra.conf
> > > >> Configuration saved to /usr/local/etc/frr/bgpd.conf
> > > >> Configuration saved to /usr/local/etc/frr/staticd.conf
> > > >> i3# sh ip route 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8>
> > > >> Routing entry for 10.0.0.0/8 <http://10.0.0.0/8>
> > <http://10.0.0.0/8>
> > > >> Known via "static", distance 1, metric 0, best
> > > >> Last update 00:00:07 ago
> > > >> * directly connected, disc0, weight 1
> > > >>
> > > >> i3#
> > > >>
> > > >> 2020/09/30 14:57:53 STATIC: Static Route using disc0
> > interface not
> > > >> installed because the interface does not exist in
> > specified vrf
> > > >> 2020/09/30 14:57:53 STATIC: Static Route using disc0
> > interface not
> > > >> installed because the interface does not exist in
> > specified vrf
> > > >>
> > > >> the kernel routing table does seem to have it installed
> > > >>
> > > >>
> > > >> # netstat -nra | grep 10.0.0
> > > >> 10.0.0.0/8 <http://10.0.0.0/8> <http://10.0.0.0/8>
> > disc0 U1
> > > 0 65532 disc0
> > > >> #
> > > >>
> > > >> What is the "proper" way to do this on frr7x ?
> > > >>
> > > >> Thanks
> > > >>
> > > >> ---Mike
> > > >>
> > > >>
> > > >>
> > > >>
> > > >> _______________________________________________
> > > >> frog mailing list
> > > >> frog at lists.frrouting.org
> > <mailto:frog at lists.frrouting.org> <mailto:frog at lists.frrouting.org
> > <mailto:frog at lists.frrouting.org>>
> > > >> https://lists.frrouting.org/listinfo/frog
> > >
> > > _______________________________________________
> > > frog mailing list
> > > frog at lists.frrouting.org <mailto:frog at lists.frrouting.org>
> > <mailto:frog at lists.frrouting.org <mailto:frog at lists.frrouting.org>>
> > > https://lists.frrouting.org/listinfo/frog
> > >
> >
>
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