<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">Coin phrase ... IRR (dedup)<br><br><div dir="ltr"><div><span style="background-color: rgba(255, 255, 255, 0);">-- </span></div><div><span style="background-color: rgba(255, 255, 255, 0);"> J. Hellenthal</span></div><div><span style="background-color: rgba(255, 255, 255, 0);"><br></span></div><span style="background-color: rgba(255, 255, 255, 0);">The fact that there's a highway to Hell but only a stairway to Heaven says a lot about anticipated traffic volume.</span></div><div dir="ltr"><br><blockquote type="cite">On Nov 29, 2021, at 07:17, Job Snijders via NANOG <nanog@nanog.org> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><div dir="auto">Hi Anurag,</div><div dir="auto"><br></div><div dir="auto">Circular dependencies definitely are a thing to keep in mind when designing IRR and RPKI pipelines!</div><div dir="auto"><br></div><div dir="auto">In the case of IRR: It is quite rare to query the RIR IRR services directly. Instead, the common practise is that utilities such as bgpq3, peval, and bgpq4 query “IRRd” (<a href="https://IRRd.net">https://IRRd.net</a>) instances at for example <a href="http://whois.radb.net">whois.radb.net</a> and <a href="http://rr.ntt.net">rr.ntt.net</a>. You can verify this with tcpdump. These IRRd instances serve as intermediate caches, and will continue to serve old cached data in case the origin is down. This phenomenon in the global IRR deployment avoids a lot of potential for circular dependencies.</div><div dir="auto"><br></div><div dir="auto">Also, some organisations use threshold checks before deploying new IRR-based filters to reduce risk of “misfiring”.</div><div dir="auto"><br></div><div dir="auto"><br></div><div dir="auto">The RPKI case is slightly different: the timers are far more aggressive compared to IRR, and until “Publish in Parent” (RFC 8181) becomes common place, there are more publication points, thus more potential for operators to paint themselves into a corner.</div><div dir="auto"><br></div><div dir="auto">Certainly, in the case of RPKI, all Publication Point (PP) operators need to take special care to not host CAs which have the PP’s INRs listed as subordinate resources inside the PP.</div><div dir="auto"><br></div><div dir="auto">See RFC 7115 Section 5 for more information: “Operators should be aware that there is a trade-off in placement of an RPKI repository in address space for which the repository’s content is authoritative. On one hand, an operator will wish to maximize control over the repository. On the other hand, if there are reachability problems to the address space, changes in the repository to correct them may not be easily access by others”</div><div dir="auto"><br></div><div dir="auto">Ryan Sleevi once told me: "yes, it strikes me that you should prevent self-compromise from being able to perpetually own yourself, by limiting an attacker’s ability to persist beyond remediation."<br></div><div dir="auto"><br></div><div dir="auto">A possible duct tape approach is outlined at <a href="https://bgpfilterguide.nlnog.net/guides/slurm_ta/">https://bgpfilterguide.nlnog.net/guides/slurm_ta/</a></div><div dir="auto">However, I can’t really recommend the SLURM file approach. Instead, RPKI repository operators are probably best off hosting their repository *outside* their own address space.</div><div dir="auto"><br></div><div dir="auto">Just like with Authoritative DNS servers, make sure you also can serve your records via a competitor! :-)</div><div dir="auto"><br></div><div dir="auto">For example, if ARIN moved one of their three publication point clusters into address space managed by any of the other four RIRs, some risk would be reduced.</div><div dir="auto"><br></div><div dir="auto">Kind regards,</div><div dir="auto"><br></div><div dir="auto">Job</div><div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, 29 Nov 2021 at 13:37, Anurag Bhatia <<a href="mailto:me@anuragbhatia.com">me@anuragbhatia.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)"><div dir="ltr">Hello everyone, <div><br></div><div>While discussing IRR on some groups recently, I was thinking if there can be (and if there is) cycling dependency in filtering where IRR (run by whoever APNIC, RIPE, RADB etc) uses some upstream and accepts only routes with existing & valid route object. </div><div><br></div><div><br></div><div><br></div><div>So hypothetical case (can apply to any IRR): </div><div><br></div><div><ol><li style="margin-left:15px">APNIC registry source is <a href="http://whois.apnic.net/" target="_blank">whois.apnic.net</a> and points to 202.12.28.136 / 2001:dc0:1:0:4777::136. The aggregate of both these has a valid route object at the APNIC registry itself. <br><br></li><li style="margin-left:15px">Their upstreams say AS X, Y and Z have tooling in place to generate and push filters by checking all popular IRRs. All is well till this point. <br><br></li><li style="margin-left:15px">Say APNIC has some server/service issue for a few mins and X Y and Z are updating their filters at the same time. They cannot contact <a href="http://whois.apnic.net/" target="_blank">whois.apnic.net</a> and hence miss generating filters for all APNIC IRR hosted prefixes. <br><br></li><li style="margin-left:15px">X, Y and Z drop APNIC prefixes including those of IRR & the loop goes on from this point onwards. </li></ol><div><br></div></div><div>So my question is: Can that actually happen? </div><div>If not, do X, Y and Z and possible all upstreams till default-free zone treat these prefixes in a special manner to avoid such loop in resolution? </div><div><br></div><div><br></div><div><br></div><div><br></div><div>Thanks! </div></div><div dir="ltr"><div><br></div>-- <br><div dir="ltr" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div><span style="font-family:arial,helvetica,sans-serif">Anurag Bhatia</span><br></div><div></div><div><font face="arial, helvetica, sans-serif" style="font-family:arial,helvetica,sans-serif;color:rgb(0,0,0)"><a href="https://anuragbhatia.com" target="_blank" style="font-family:arial,helvetica,sans-serif">anuragbhatia.com</a></font></div></div></div></div></div></div></div>
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