Seasoned Contributor

TWC DNS servers don't use IPv6 for transport leading to issues.

I'm starting a new thread regarding an old question.  As we can see below if a nameserver only has an IPv6 address the TWC resolvers can't use it.  It would be nice if TWC would at least acknowldege this issue.

 

$ dig @209.18.47.61 -t AAAA ipv6.l.google.com

; <<>> DiG 9.9.5-3ubuntu0.8-Ubuntu <<>> @209.18.47.61 -t AAAA ipv6.l.google.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1103
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; ANSWER SECTION:
ipv6.l.google.com.    300    IN    AAAA    2607:f8b0:4002:c07::64

 

$ dig @209.18.47.61 -t AAAA ds.v6ns.test-ipv6.com

; <<>> DiG 9.9.5-3ubuntu0.8-Ubuntu <<>> @209.18.47.61 -t AAAA ds.v6ns.test-ipv6.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 1875
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

 

$ dig -t AAAA ds.v6ns.test-ipv6.com

; <<>> DiG 9.9.5-3ubuntu0.8-Ubuntu <<>> -t AAAA ds.v6ns.test-ipv6.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46974
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;ds.v6ns.test-ipv6.com.        IN    AAAA

;; ANSWER SECTION:
ds.v6ns.test-ipv6.com.    360    IN    AAAA    2001:470:1:18::119


;; AUTHORITY SECTION:
v6ns.test-ipv6.com.    15    IN    NS    v6ns1.test-ipv6.com.

 

$ dig -t any v6ns1.test-ipv6.com.
; <<>> DiG 9.9.5-3ubuntu0.8-Ubuntu <<>> -t any v6ns1.test-ipv6.com.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21778
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 5

;; ANSWER SECTION:
v6ns1.test-ipv6.com.    198    IN    AAAA    2001:470:1:18::119
11 REPLIES
Expert

Re: TWC DNS servers don't use IPv6 for transport leading to issues.

This is peer to peer support, Send bug reports to TWC via the DSL reports TWC link

IPv4 and IPv6 dns is handled seperately via different routes to different TWC RDC's. 

 All traffic hits the area's RDC , IPv4 is resolved there, IPv6 is sent further down the pipeline to a single datacenter in Witchita.  it's 3-6 hops and 10-15000 ms later ( and if your devices time out after 3000 ms it fails)

 

compare tracert's...

Supposedly that will be changed within a year pending Charter purchase/takeover.

.

209.18.47.61/62 can't handle IPv6... 

 TWC knows there's an issue. It also affects EMTA traffic which is handled by a 3rd, seperate datacenter.

 

Seasoned Contributor

Re: TWC DNS servers don't use IPv6 for transport leading to issues.


MsRaye wrote: IPv6 is sent further down the pipeline to a single datacenter in Witchita.  3-6 hops and 10-50 ms later

 


Again you're making unhelpful comments that are not germane.  You also continue to repeat the false statement that IPv6 resolution takes significantly longer than IPv4.  13msec is not  longer than 61msec and 10-50 msec is within the variability of any DNS cache with the possible exception of Google.

 

; <<>> DiG 9.9.5-3ubuntu0.8-Ubuntu <<>> @209.18.47.61 -t A ipv4.l.google.com

;; QUESTION SECTION:
;ipv4.l.google.com.		IN	A

;; ANSWER SECTION:
ipv4.l.google.com.	300	IN	A	173.194.219.100

;; Query time: 61 msec
;; SERVER: 209.18.47.61#53(209.18.47.61)
;; WHEN: Wed Apr 13 13:20:45 EDT 2016
;; MSG SIZE  rcvd: 142


; <<>> DiG 9.9.5-3ubuntu0.8-Ubuntu <<>> @209.18.47.61 -t AAAA ipv6.l.google.com

;ipv6.l.google.com.		IN	AAAA

;; ANSWER SECTION:
ipv6.l.google.com.	300	IN	AAAA	2607:f8b0:4002:c08::66

;; Query time: 13 msec
;; SERVER: 209.18.47.61#53(209.18.47.61)
;; WHEN: Wed Apr 13 13:20:45 EDT 2016
;; MSG SIZE  rcvd: 74

 

Expert

Re: TWC DNS servers don't use IPv6 for transport leading to issues.

Sorry but everything east of the Mississippi is slower Only TX has equivalent speeds since both are resolved out of Witchita... Where are you? Yes it's important... Main issue is that this is a CMTS and routing issue, TWC can't program 2 of them to work the same, they should really stick to cable tv as their IP infrastructure is horrible.

 They won't admit it here, look on other forums.

 

 Your tracert times are irrelevant...  they went to Google.com  not the TWC DNS rdc's which are probably in different states . TWC has changed all geolocation data to the same fictisious place and they are no longer accurate in whois... An Ipv4 tracert shows most of the local mneomics

 

 

 

 

Seasoned Contributor

Re: TWC DNS servers don't use IPv6 for transport leading to issues.


@MsRaye wrote:

Sorry but everything east of the Mississippi is slower

 

 


Again you're making unhelpful comments that are not germane.  It's been explained to you that TWC uses anycast. I live in New York state which is reasonably far east of the Mississippi and my instance of 209.18.47.61 is in Syracuse NY.

 

But as I said your comments are not germane to my original post which is about getting a SERVFAIL response from the TWC resolver when querying an IPv6 only nameserver.

Expert

Re: TWC DNS servers don't use IPv6 for transport leading to issues.

If your router does not have seperate dns v4 and dns v6 IP address capability you are correct. The  Syracuse RDC does not resolve IPv6, i believe it still passes it off to Witchita . It's a horribly slow path at times and can take 5-30 seconds and yes there have been complaints about the lag and it timing out which may be related to your actual complaint. .

 Again, complain to TWC over at the DSL site, The anycast makes it impossible to troubleshoot any issues by us forum users, Tier1, 2 and probably Tier3 , and twc went and hid all the geolocation as well. This is a Tier 4 issue and they aren't here They got rattled when I published their public contact info, lol. ...

 

Seasoned Contributor

Re: TWC DNS servers don't use IPv6 for transport leading to issues.


@MsRaye wrote:

 Your tracert times are irrelevant...  they went to Google.com  not the TWC DNS rdc's which are probably in different states


If you could read the output of dig (which is not traceroute) you would know your comment is completely wrong.

 

This summary of the dig command means a query for the IPv6 (AAAA record) address of ipv6.l.google.com was sent to 209.18.47.61. We use the ip address of dns-cac-lb-01-rr.com and the CNAME value for ipv6.google.com to avoid extra lookups.

@; <<>> DiG 9.9.5-3ubuntu0.8-Ubuntu <<>> @209.18.47.61 -t AAAA ipv6.l.google.com

 

This line means it took 13 msec to complete the query.

;; Query time: 13 msec

 

This line means the query was sent to 209.18.47.61 port 53 i.e. dns-cac-lb-01.rr.com

;; SERVER: 209.18.47.61#53(209.18.47.61)

 

These lines mean the server responded with the IPv6 address of ipv6.l.google.com as 2607:f8b0:4002:c08::66 (which reverses to yx-in-x66.1e100.net)

;; ANSWER SECTION:

ipv6.l.google.com. 300 IN AAAA 2607:f8b0:4002:c08::66

Expert

Re: TWC DNS servers don't use IPv6 for transport leading to issues.

OK, is this on your 6141  or the 6183?

This was not the case back in December, It really looks like part of whatever TWC did to the CMTS boxes at the head ends which resulted in them turning off IPv6 in 6183's because there was "a 6183 issue"

 Look in the 6141's log and see if it's getting commands settings from IPv6 addy's. If not, TWC hasn't "fixed" that one yet.

 You and I are also on different RDC's, Mines in Columbus, Yours is in Syracuse. There's a huge push here to improve internet for the RNC by all providers.

 

Some of the US has gotten altered CMTS FW regarding the Time server . Mine here is administered by IPv6 and other parts of the country by IPv4. This change here in NEO occurred about 2 weeks ago.

 SO TWC is tweaking CMTS settings one at a time, not globally.

Seasoned Contributor

Re: TWC DNS servers don't use IPv6 for transport leading to issues.


@MsRaye wrote:

OK, is this on your 6141  or the 6183?

This was not the case back in December, It really looks like part of whatever TWC did to the CMTS boxes


I've asked you not to post in threads I've started because your comments are persistently wrong.

 

You don't understand the problem. It doesn't have anything to do with my CM (which is Netgear), my CMTS or if I have IPv6.

 

If National Grid turned off the power to the TWC facilities in Buffalo would you say it was because of a CMTS update?

 

As long as

   @Dig @209.18.47.61 -t AAAA ds.v6ns.test-ipv6.com

returns

  status: SERVFAIL

instead of

  status: NOERROR

TWC has an internal configuration issue.

Not applicable

Re: TWC DNS servers don't use IPv6 for transport leading to issues.

MsRaye,

 

You don't know what you are talking about.  If you can not post valid information... Please don't post.

I'm a system administrator and run both an IPv4 and IPv6 DNS servers.  They are two Sun Microsystems UNIX machines (one running as the Master DNS server and the other as the Secondary DNS server) and adding IPv6 to the already run IPv4 DNS service took less than five minutes and restarting the service.  No reboot required.

 

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