[dns-operations] Charter/Spectrum resolver trouble

[Seth Mattinen]

On 4/8/21 8:48 PM, Seth Mattinen wrote:
> On 4/8/21 10:07 AM, Seth Mattinen wrote:
>> Is there someone from Charter/Spectrum who is responsible for 
>> resolvers 71.10.216.1 and 71.10.216.2 on here? I have a customer 
>> that's getting SERVFAIL responses from those DNS servers for zones 
>> they host. All the usual public DNS and other provider's DNS servers 
>> are fine.
>>
> 
> Figured out the issue; there appears to be a routing loop in AS6939 to 
> prefix 68.114.45.0/24. Sending traffic out over a different transit AS 
> resolves it for now.


One last clarification; after digging by HE the problem is/was Charter 
advertising 68.114.45.0/24 and then looping traffic back to HE for 
unknown reasons. HE worked around this by filtering the announcement for 
68.114.45.0/24 at that point.