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@sentex.net <mailto:mike@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@sentex.net <mailto:mike@sentex.net> > <mailto:mike@sentex.net <mailto:mike@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@sentex.net <mailto:mike@sentex.net> > <mailto:mike@sentex.net <mailto:mike@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@lists.frrouting.org <mailto:frog@lists.frrouting.org> <mailto:frog@lists.frrouting.org <mailto:frog@lists.frrouting.org>> > >> https://lists.frrouting.org/listinfo/frog > > _______________________________________________ > frog mailing list > frog@lists.frrouting.org <mailto:frog@lists.frrouting.org> <mailto:frog@lists.frrouting.org <mailto:frog@lists.frrouting.org>> > https://lists.frrouting.org/listinfo/frog >