[Cerowrt-devel] Problems with DNSsec on Comcast, with Cero 3.10.38-1/DNSmasq 4-26-2014

Dave Taht dave.taht at gmail.com
Mon Apr 28 13:03:35 EDT 2014

On Mon, Apr 28, 2014 at 9:55 AM, Jim Gettys <jg at freedesktop.org> wrote:

> ​​Comcast recently lit up IPv6 native dual stack in the Boston area.
> The http://test-ipv6.com/ web site complains about DNS problems unless
> dnssec is disabled; if it is, I get various timeouts.
 Test with IPv4 DNS record
> ok (4.196s)
> Test with IPv6 DNS record
> ok (0.115s) using ipv6
> Test with Dual Stack DNS record
> timeout (11.882s)

I  don't  know what this test does. try a local query over ipv6?

Test for Dual Stack DNS and large packet
> timeout (11.817s)
> Test IPv4 without DNS
> ok (0.214s) using ipv4
> Test IPv6 without DNS
> ok (0.204s) using ipv6
> Test IPv6 large packet
> ok (0.120s) using ipv6
> Test if your ISP's DNS server uses IPv6
> slow (8.752s)
> Find IPv4 Service Provider
> timeout (11.968s)
> Find IPv6 Service Provider
> ok (0.126s) using ipv6 ASN 7922
> Test for buggy DNS
> undefined (5.003s)
> DNS server addresses look reasonable for Comcast.
> DNS 1:
> DNS 2:

To try to isolate  things a little  bit, you can turn off fetching ipv4 dns

option peerdns  '0'

in the wan (ge00) stanza  of /etc/config/network

and let the wan6 stanza fetch them.

A packet capture of it working vs not working would be good.

tcpdump  -i ge00 -w cap1.cap port 53

Also  capture on the local interface.

DNS 1: 2001:558:feed::1
> DNS 2: 2001:558:feed::2
> Today, the problem seems consistent with turning dnssec on and off on the
> router.  If enabled, I have problems; if disabled, I get a clean bill of
> health out of test-ipv6.com.
>                                              - Jim
> _______________________________________________
> Cerowrt-devel mailing list
> Cerowrt-devel at lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/cerowrt-devel

Dave Täht

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