lairdjn's profile

Contributor

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46 Messages

Tuesday, March 9th, 2021 4:00 PM

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DNS doesn't resolve certain sites today

I have an Xfinity gateway, so its DNS servers are whatever they are (75.75.75.75 and 75.75.76.76).  I can't change them.

 

Today I noticed that the URL to my bank doesn't resolve, i.e. I get a DNS error.  Pretty much everything else does.  Go figure.

 

When I log on to my job's corporate VPN (thus bypassing the Comcast DNS servers), the host resolves just fine, so the host is up, the domain hasn't expired, etc. etc.  From the standpoint of my network, the bank's hostname is unresolvable.

 

What options do I have to fix this problem if it doesn't magically go away soon?  Is this a "reboot and everything will be fine mysteriously" situation? 🙂

Problem Solver

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1.5K Messages

4 years ago

Aside from swapping out equipment to 3rd party (and saving the rental fee), there's nothing on your end that can fix a DNS issue.  Like you say, you're locked to 75/76 using their equipment.

 

I have current installs in two states under Xfinity and Spectrum (formerly Charter).  I found the default DNS comcast servers to be really wonky on both of them.  Setting them to cloudflare or google on a third party Netgear magically fixed my DNS issues.  "dig query" to cloudflare/google and even oddballs like afraid.org  is faster too, which is odd because in theory, your direct upstream DNS should be faster.

 

About all you can do, is look at the cable connection stats/power/snr to see if your DNS issue is really just a network stall issue, but that's probably not it if you can get to everything else while it's going on. 

 

Perhaps they have cache issues, dnsbl list lookup delay (advanced security?), or some other bottleneck, but crippling the ability to use something else is a deal breaker on equipment for me.

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