<div dir="ltr">Can you not just blackhole it? `ip route *****/* blackhole`<br><br>As to why its allowed into the config... i'm not sure, it seems that was intentionally allowed according to the patch.</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Oct 1, 2020 at 11:41 AM mike tancsa <<a href="mailto:mike@sentex.net">mike@sentex.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">What is the preferred syntax going forward ? I just want to tie down<br>
larger prefixes to the discard interface so any packets sent to dead<br>
space just get discarded. I dont want icmp messages sent back.<br>
<br>
ip route <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> disc0 ?<br>
<br>
Also, if the old syntax is not going to work, perhaps not allow it in<br>
the config ?<br>
<br>
---Mike<br>
<br>
On 10/1/2020 11:31 AM, Stephen Worley wrote:<br>
> this was disallowed starting<br>
> with <a href="https://github.com/FRRouting/frr/pull/4302" rel="noreferrer" target="_blank">https://github.com/FRRouting/frr/pull/4302</a> <br>
><br>
> If you have a valid use case might be worth discussing with the author<br>
> over slack.<br>
><br>
> On Thu, Oct 1, 2020 at 9:33 AM mike tancsa <<a href="mailto:mike@sentex.net" target="_blank">mike@sentex.net</a><br>
> <mailto:<a href="mailto:mike@sentex.net" target="_blank">mike@sentex.net</a>>> wrote:<br>
><br>
> Hi Donald, the 10.128.128.144 is the disc0 interface on my production<br>
> router running frr6 and it works as expected. I setup another test box<br>
> with frr6 and used the same disc0 ip config<br>
><br>
><br>
> e.g. on frr6<br>
><br>
> # ifconfig disc0<br>
> disc0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 65532<br>
> inet 10.128.128.1 netmask 0xfffffffc<br>
> groups: disc<br>
> nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL><br>
><br>
> frr6# sh ip route connected<br>
> Codes: K - kernel route, C - connected, S - static, R - RIP,<br>
> O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,<br>
> T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,<br>
> F - PBR,<br>
> > - selected route, * - FIB route<br>
><br>
> C>* <a href="http://10.128.128.0/30" rel="noreferrer" target="_blank">10.128.128.0/30</a> <<a href="http://10.128.128.0/30" rel="noreferrer" target="_blank">http://10.128.128.0/30</a>> is directly<br>
> connected, disc0, 00:00:19<br>
><br>
> frr6# sh ip route 10.128.128.1<br>
> Routing entry for <a href="http://10.128.128.0/30" rel="noreferrer" target="_blank">10.128.128.0/30</a> <<a href="http://10.128.128.0/30" rel="noreferrer" target="_blank">http://10.128.128.0/30</a>><br>
> Known via "connected", distance 0, metric 1, best<br>
> Last update 00:00:42 ago<br>
> * directly connected, disc0<br>
><br>
> frr6# conf t<br>
> frr6(config)# ip route <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>> 10.128.128.1<br>
> frr6(config)# ^Z<br>
> frr6# sh ip route <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>><br>
> Routing entry for <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>><br>
> Known via "static", distance 1, metric 0, best<br>
> Last update 00:00:06 ago<br>
> * 10.128.128.1, via disc0<br>
><br>
> frr6#<br>
><br>
><br>
> on frr7<br>
><br>
> frr7# sh ip route connected<br>
> Codes: K - kernel route, C - connected, S - static, R - RIP,<br>
> O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,<br>
> T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,<br>
> F - PBR, f - OpenFabric,<br>
> > - selected route, * - FIB route, q - queued route, r -<br>
> rejected<br>
> route<br>
><br>
> C>* <a href="http://10.128.128.0/30" rel="noreferrer" target="_blank">10.128.128.0/30</a> <<a href="http://10.128.128.0/30" rel="noreferrer" target="_blank">http://10.128.128.0/30</a>> [0/1] is directly<br>
> connected, disc0, 00:24:49<br>
><br>
> frr7# sh ip route 10.128.128.1<br>
> Routing entry for <a href="http://10.128.128.0/30" rel="noreferrer" target="_blank">10.128.128.0/30</a> <<a href="http://10.128.128.0/30" rel="noreferrer" target="_blank">http://10.128.128.0/30</a>><br>
> Known via "connected", distance 0, metric 1, best<br>
> Last update 00:25:07 ago<br>
> * directly connected, disc0<br>
><br>
> frr7# conf t<br>
> frr7(config)# ip route <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>> 10.128.128.1<br>
> % Warning!! Local connected address is configured as Gateway<br>
> IP(10.128.128.1)<br>
><br>
> frr7# sh ip route <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>><br>
> % Network not in table<br>
> frr7#<br>
><br>
> ---Mike<br>
><br>
><br>
><br>
> On 10/1/2020 8:00 AM, Donald Sharp wrote:<br>
> > Can we see the output of `show ip route 10.128.128.144` and `show ip<br>
> > route connected`?<br>
> ><br>
> > donald<br>
> ><br>
> > On Wed, Sep 30, 2020 at 3:03 PM mike tancsa <<a href="mailto:mike@sentex.net" target="_blank">mike@sentex.net</a><br>
> <mailto:<a href="mailto:mike@sentex.net" target="_blank">mike@sentex.net</a>>> wrote:<br>
> >> Up to version 6.x of frr, I have been able to tie down larger<br>
> prefixes<br>
> >> with a static routing pointing to the discard interface on FreeBSD.<br>
> >><br>
> >> eg. the static route entry<br>
> >><br>
> >> ip route <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>> 10.128.128.144<br>
> >><br>
> >> # sh ip route <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>><br>
> >> Routing entry for <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>><br>
> >> Known via "static", distance 1, metric 0, best<br>
> >> Last update 09w0d01h ago<br>
> >> * 10.128.128.144, via disc0<br>
> >><br>
> >> where disc0 is<br>
> >><br>
> >> # ifconfig disc0<br>
> >> disc0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 65532<br>
> >> inet 10.128.128.144 netmask 0xfffffffc<br>
> >> inet6 fe80::1%disc0 prefixlen 64 scopeid 0x8<br>
> >> inet6 2001:db8::1 prefixlen 64<br>
> >> groups: disc<br>
> >> nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL><br>
> >><br>
> >><br>
> >> however, on frr7.4 this no longer works,<br>
> >><br>
> >> On my test box<br>
> >><br>
> >> % ifconfig disc0<br>
> >> disc0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 65532<br>
> >> inet 10.128.128.1 netmask 0xfffffffc<br>
> >> inet6 fe80::1%disc0 prefixlen 64 scopeid 0x6<br>
> >> groups: disc<br>
> >> nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL><br>
> >><br>
> >><br>
> >><br>
> >> i3# conf t<br>
> >> i3(config)# ip route <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>> 10.128.128.1<br>
> >> % Warning!! Local connected address is configured as Gateway<br>
> >> IP(10.128.128.1)<br>
> >> i3(config)#<br>
> >><br>
> >> i3# sh ip route <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>><br>
> >> % Network not in table<br>
> >> i3#<br>
> >><br>
> >> If I user disc0, it seems to work, but I get warnings on start up<br>
> >><br>
> >> i3(config)# ip route <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>> disc0<br>
> >><br>
> >> i3# wr<br>
> >> Note: this version of vtysh never writes vtysh.conf<br>
> >> Building Configuration...<br>
> >> Configuration saved to /usr/local/etc/frr/zebra.conf<br>
> >> Configuration saved to /usr/local/etc/frr/bgpd.conf<br>
> >> Configuration saved to /usr/local/etc/frr/staticd.conf<br>
> >> i3# sh ip route <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>><br>
> >> Routing entry for <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>><br>
> >> Known via "static", distance 1, metric 0, best<br>
> >> Last update 00:00:07 ago<br>
> >> * directly connected, disc0, weight 1<br>
> >><br>
> >> i3#<br>
> >><br>
> >> 2020/09/30 14:57:53 STATIC: Static Route using disc0 interface not<br>
> >> installed because the interface does not exist in specified vrf<br>
> >> 2020/09/30 14:57:53 STATIC: Static Route using disc0 interface not<br>
> >> installed because the interface does not exist in specified vrf<br>
> >><br>
> >> the kernel routing table does seem to have it installed<br>
> >><br>
> >><br>
> >> # netstat -nra | grep 10.0.0<br>
> >> <a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">10.0.0.0/8</a> <<a href="http://10.0.0.0/8" rel="noreferrer" target="_blank">http://10.0.0.0/8</a>> disc0 U1 <br>
> 0 65532 disc0<br>
> >> #<br>
> >><br>
> >> What is the "proper" way to do this on frr7x ?<br>
> >><br>
> >> Thanks<br>
> >><br>
> >> ---Mike<br>
> >><br>
> >><br>
> >><br>
> >><br>
> >> _______________________________________________<br>
> >> frog mailing list<br>
> >> <a href="mailto:frog@lists.frrouting.org" target="_blank">frog@lists.frrouting.org</a> <mailto:<a href="mailto:frog@lists.frrouting.org" target="_blank">frog@lists.frrouting.org</a>><br>
> >> <a href="https://lists.frrouting.org/listinfo/frog" rel="noreferrer" target="_blank">https://lists.frrouting.org/listinfo/frog</a><br>
><br>
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><br>
</blockquote></div>