Mailing List Archive

I as well seem to be having issues resolving DNS on comcast.

On Mon, Jul 6, 2020 at 8:57 AM Dave Dechellis <dechellis@gmail.com> wrote:

> Hello,
>
> Last night we made some changes to our DNS-SEC environment at Tufts
> University and all changes seem to have propagated - but we're having
> issues resolving against Comcast's DNS servers.
>
> All DNS-SEC checking seems to be looking good post changes and other
> ISPs are resolving fine.
>
> Is there anyone from Comcast who might be able to validate behavior?
> I'm assuming it might take up to 1 day for TTL propagation.
>
> Thanks
> Dave
> David.DeChellis@tufts.edu
>

On Sun, Jul 05, 2020 at 09:30:27AM -0400,
Dave Dechellis <dechellis@gmail.com> wrote
a message of 15 lines which said:

> Last night we made some changes to our DNS-SEC environment at Tufts
> University and all changes seem to have propagated - but we're having
> issues resolving against Comcast's DNS servers.

RIPE Atlas probes on the Comcast AS do not show problems:

% blaeu-resolve --as 7922 --type MX --requested 100 --displayvalidation tufts.edu
[. (Authentic Data flag) 5 ppagent-prod-01.uit.tufts.edu. 5 ppagent-prod-02.uit.tufts.edu. 5 ppagent-prod-03.uit.tufts.edu. 5 ppagent-prod-04.uit.tufts.edu. 5 ppagent-prod-05.uit.tufts.edu. 5 ppagent-prod-06.uit.tufts.edu.] : 70 occurrences
[.5 ppagent-prod-01.uit.tufts.edu. 5 ppagent-prod-02.uit.tufts.edu. 5 ppagent-prod-03.uit.tufts.edu. 5 ppagent-prod-04.uit.tufts.edu. 5 ppagent-prod-05.uit.tufts.edu. 5 ppagent-prod-06.uit.tufts.edu.] : 28 occurrences
[ERROR: SERVFAIL] : 1 occurrences
Test #26172909 done at 2020-07-06T15:07:12Z

(The one SERVFAIL seems to be on a probe which does not use Comcast resolvers.)