<html><head></head><body><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;">Hello,</div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><br></div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;">I am testing ecs support using unbound 1.6.4 and I face the same problem that another user reported back in May 6, 2015.</div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><br></div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;">I have a CNAME record that is managed by my own authoritative that has edns support and with expected scope prefix-length (/16 as in my example [1]) and that record points to another CNAME which is managed by AWS DNS which responded with scope prefix-length /0. unbound cached the response with scope prefix-length /0 rather than /16 and subsequent lookups for the same record with different client-subnet got served from that cache. This is a bit surprising as it is counter-intuitive to not use the max prefix-length from the whole chain for caching responses.</div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><br></div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;">Is there a plan for unbound to start to implement using max prefix-length from whole chain for cache lookup?</div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><br></div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;">Also, when unbound caches each of the lookup for records in the chain? does it have separate cache entries for each lookup or only one entry for the RRsets for the whole chain?<br></div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><br></div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><br></div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;">[1]</div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><br></div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;">$ dig @127.0.0.1 egress01.insnw.net +subnet=52.65.177.7<br><br>; <<>> DiG 9.11.0-P3 <<>> @127.0.0.1 egress01.insnw.net +subnet=52.65.177.7<br>; (1 server found)<br>;; global options: +cmd<br>;; Got answer:<br>;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44886<br>;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 4, ADDITIONAL: 1<br><br>;; OPT PSEUDOSECTION:<br>; EDNS: version: 0, flags:; udp: 4096<br>; CLIENT-SUBNET: 52.65.177.7/32/0<br>;; QUESTION SECTION:<br>;egress01.insnw.net. IN A<br><br>;; ANSWER SECTION:<br>egress01.insnw.net. 300 IN CNAME ofetch01-syd02.svc.insnw.net.<br>ofetch01-syd02.svc.insnw.net. 600 IN CNAME nlb-72fb7d7a9fecee0d.elb.ap-southeast-2.amazonaws.com.<br>nlb-72fb7d7a9fecee0d.elb.ap-southeast-2.amazonaws.com. 60 IN A 13.54.22.31<br>nlb-72fb7d7a9fecee0d.elb.ap-southeast-2.amazonaws.com. 60 IN A 52.64.79.11<br><br>;; AUTHORITY SECTION:<br>elb.ap-southeast-2.amazonaws.com. 172800 IN NS ns-1110.awsdns-10.org.<br>elb.ap-southeast-2.amazonaws.com. 172800 IN NS ns-13.awsdns-01.com.<br>elb.ap-southeast-2.amazonaws.com. 172800 IN NS ns-1571.awsdns-04.co.uk.<br>elb.ap-southeast-2.amazonaws.com. 172800 IN NS ns-527.awsdns-01.net.<br><br>;; Query time: 1462 msec<br>;; SERVER: 127.0.0.1#53(127.0.0.1)<br>;; WHEN: Wed Feb 14 23:23:02 UTC 2018<br>;; MSG SIZE rcvd: 324<br><br>$ dig @127.0.0.1 egress01.insnw.net +subnet=52.57.28.138<br><br>; <<>> DiG 9.11.0-P3 <<>> @127.0.0.1 egress01.insnw.net +subnet=52.57.28.138<br>; (1 server found)<br>;; global options: +cmd<br>;; Got answer:<br>;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 10223<br>;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 4, ADDITIONAL: 1<br><br>;; OPT PSEUDOSECTION:<br>; EDNS: version: 0, flags:; udp: 4096<br>;; QUESTION SECTION:<br>;egress01.insnw.net. IN A<br><br>;; ANSWER SECTION:<br>egress01.insnw.net. 277 IN CNAME ofetch01-syd02.svc.insnw.net.<br>ofetch01-syd02.svc.insnw.net. 577 IN CNAME nlb-72fb7d7a9fecee0d.elb.ap-southeast-2.amazonaws.com.<br>nlb-72fb7d7a9fecee0d.elb.ap-southeast-2.amazonaws.com. 37 IN A 13.54.22.31<br>nlb-72fb7d7a9fecee0d.elb.ap-southeast-2.amazonaws.com. 37 IN A 52.64.79.11<br><br>;; AUTHORITY SECTION:<br>elb.ap-southeast-2.amazonaws.com. 172777 IN NS ns-1110.awsdns-10.org.<br>elb.ap-southeast-2.amazonaws.com. 172777 IN NS ns-13.awsdns-01.com.<br>elb.ap-southeast-2.amazonaws.com. 172777 IN NS ns-1571.awsdns-04.co.uk.<br>elb.ap-southeast-2.amazonaws.com. 172777 IN NS ns-527.awsdns-01.net.<br><br>;; Query time: 0 msec<br>;; SERVER: 127.0.0.1#53(127.0.0.1)<br>;; WHEN: Wed Feb 14 23:23:25 UTC 2018<br>;; MSG SIZE rcvd: 312<br><br>$ dig @ns1.insnw.net egress01.insnw.net +subnet=52.57.28.138<br><br>; <<>> DiG 9.11.0-P3 <<>> @ns1.insnw.net egress01.insnw.net +subnet=52.57.28.138<br>; (1 server found)<br>;; global options: +cmd<br>;; Got answer:<br>;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11138<br>;; flags: qr aa rd; QUERY: 1, ANSWER: 2, AUTHORITY: 2, ADDITIONAL: 3<br>;; WARNING: recursion requested but not available<br><br>;; OPT PSEUDOSECTION:<br>; EDNS: version: 0, flags:; udp: 4096<br>; COOKIE: 45e8e0a01ad26d47ab5fd11c5a84c51ee9a8998944593e1d (good)<br>; CLIENT-SUBNET: 52.57.28.138/32/16<br>;; QUESTION SECTION:<br>;egress01.insnw.net. IN A<br><br>;; ANSWER SECTION:<br>egress01.insnw.net. 300 IN CNAME ofetch01-fra02.svc.insnw.net.<br>ofetch01-fra02.svc.insnw.net. 600 IN A 35.156.66.126<br><br>;; AUTHORITY SECTION:<br>insnw.net. 86400 IN NS ns2.insnw.net.<br>insnw.net. 86400 IN NS ns1.insnw.net.<br><br>;; ADDITIONAL SECTION:<br>ns1.insnw.net. 86400 IN A 192.33.29.21<br>ns2.insnw.net. 86400 IN A 192.33.29.22<br><br>;; Query time: 0 msec<br>;; SERVER: 192.33.29.21#53(192.33.29.21)<br>;; WHEN: Wed Feb 14 23:24:14 UTC 2018<br>;; MSG SIZE rcvd: 204<br><br>$ dig @ns-1110.awsdns-10.org. nlb-72fb7d7a9fecee0d.elb.ap-southeast-2.amazonaws.com. +subnet=52.65.177.7<br><br>; <<>> DiG 9.11.0-P3 <<>> @ns-1110.awsdns-10.org. nlb-72fb7d7a9fecee0d.elb.ap-southeast-2.amazonaws.com. +subnet=52.65.177.7<br>; (2 servers found)<br>;; global options: +cmd<br>;; Got answer:<br>;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36514<br>;; flags: qr aa rd; QUERY: 1, ANSWER: 2, AUTHORITY: 4, ADDITIONAL: 1<br>;; WARNING: recursion requested but not available<br><br>;; OPT PSEUDOSECTION:<br>; EDNS: version: 0, flags:; udp: 4096<br>; CLIENT-SUBNET: 52.65.177.7/32/0<br>;; QUESTION SECTION:<br>;nlb-72fb7d7a9fecee0d.elb.ap-southeast-2.amazonaws.com. IN A<br><br>;; ANSWER SECTION:<br>nlb-72fb7d7a9fecee0d.elb.ap-southeast-2.amazonaws.com. 60 IN A 13.54.22.31<br>nlb-72fb7d7a9fecee0d.elb.ap-southeast-2.amazonaws.com. 60 IN A 52.64.79.11<br><br>;; AUTHORITY SECTION:<br>elb.ap-southeast-2.amazonaws.com. 172800 IN NS ns-1110.awsdns-10.org.<br>elb.ap-southeast-2.amazonaws.com. 172800 IN NS ns-13.awsdns-01.com.<br>elb.ap-southeast-2.amazonaws.com. 172800 IN NS ns-1571.awsdns-04.co.uk.<br>elb.ap-southeast-2.amazonaws.com. 172800 IN NS ns-527.awsdns-01.net.<br><br>;; Query time: 161 msec<br>;; SERVER: 2600:9000:5304:5600::1#53(2600:9000:5304:5600::1)<br>;; WHEN: Wed Feb 14 23:24:48 UTC 2018<br>;; MSG SIZE rcvd: 262<br></div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><br></div></div></body></html>