snar
commented
3 years ago On Fri, Mar 19, 2021 at 01:50:42PM -0700, Louis He wrote:
Hello, route-filter 38.35.64.0/18 prefix-length-range /19-/24; I think it should be 38.35.64.0/18 upto /24 Not sure why BGPQ make that prefix-length-range /19-/24
Because there are no route-object for 38.35.64.0/18:
whois -h whois.ra.net 38.35.64.0/18 route: 38.0.0.0/8 descr: Cogent origin: AS174
and 38.0.0.0/8 is not included in a list because as174 is not a member of AS-ROOTNETWORKS.
Details:
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if you run bgpq3 without -r, -R and -A you will find that there are route-objects for 38.35.64.0/19, 38.35.64.0/24 to 38.35.95.0/24, 38.35.96.0/19 and 38.35.96.0/24 to 38.35.127.0/24:
route-filter 38.35.64.0/19 exact; route-filter 38.35.64.0/24 exact; [...] route-filter 38.35.95.0/24 exact; route-filter 38.35.96.0/19 exact; route-filter 38.35.96.0/24 exact; [...] route-filter 38.35.127.0/24 exact;
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these prefixes can be aggregated (-A) into two exactly matching sets:
route-filter 38.35.64.0/18 prefix-length-range /19-/19; route-filter 38.35.64.0/18 prefix-length-range /24-/24;
(two /19 forms first aggregate and 64 /24 second one).
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when adding -r 8 -R 24 (generate more-specifics for existing routes), these two lines collapse into one
route-filter 38.35.64.0/18 prefix-length-range /19-/24;
because all the more-specific /20../23 routes are autogenerated as a result of -r and -R options. However, less-specific route 38.35.64.0/18 is NOT autogenerated and thus is not allowed by filter.
@.***:~/bgpq3# ./bgpq3 -AJEl ibgp-as32708-import-ipv4/from-as32708 -r 8 -R 24 AS-ROOTNETWORKS policy-options { policy-statement ibgp-as32708-import-ipv4 { term from-as32708 { replace: from { route-filter 23.191.192.0/24 exact; route-filter 23.247.5.0/24 exact; route-filter 23.247.9.0/24 exact; route-filter 23.247.44.0/24 exact; route-filter 23.247.48.0/24 exact; route-filter 23.247.56.0/24 exact; route-filter 23.247.62.0/24 exact; route-filter 23.247.103.0/24 exact; route-filter 23.247.111.0/24 exact; route-filter 38.18.152.0/21 upto /24; route-filter 38.21.16.0/20 upto /24; route-filter 38.35.64.0/18 prefix-length-range /19-/24; route-filter 38.106.9.0/24 exact; route-filter 38.145.224.0/19 upto /24; route-filter 38.240.128.0/21 upto /24; route-filter 45.65.44.0/22 upto /24; route-filter 85.92.100.0/22 upto /24; route-filter 102.140.80.0/20 upto /24; route-filter 103.91.56.0/22 upto /24; route-filter 103.108.188.0/23 upto /24; route-filter 103.115.204.0/23 upto /24; route-filter 103.143.86.0/23 upto /24; route-filter 103.211.0.0/22 upto /24; route-filter 103.213.244.0/22 upto /24; route-filter 104.148.0.0/24 exact; route-filter 104.148.10.0/24 exact; route-filter 104.148.46.0/24 exact; route-filter 123.253.104.0/22 upto /24; route-filter 123.253.108.0/24 exact; route-filter 154.27.128.0/19 upto /24; route-filter 156.0.76.0/22 upto /24; route-filter 181.214.226.0/23 upto /24; route-filter 181.214.232.0/22 upto /24; route-filter 181.215.245.0/24 exact; route-filter 191.96.35.0/24 exact; route-filter 191.96.72.0/23 upto /24; route-filter 191.96.78.0/24 exact; route-filter 191.96.92.0/24 exact; route-filter 191.96.114.0/24 exact; route-filter 191.101.204.0/22 upto /24; } } } }
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louishot
Hello, route-filter 38.35.64.0/18 prefix-length-range /19-/24; I think it should be 38.35.64.0/18 upto /24 Not sure why BGPQ make that prefix-length-range /19-/24