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#1 2021-03-26 18:53:01

omernaveedxyz
Member
Registered: 2020-12-31
Posts: 30

[Solved] Unable to ping domain names, but ping ip works fine

I am running NetworkManager through systemd. Everything works fine on my browser, no noticeable issues. But when I try to run any commands through the terminal (youtube-dl, stack build, etc), I get timeouts and errors. I tried to ping archlinux.org, but the command gets stuck at

PING archlinux.org(archlinux.org (2a01:4f9:c010:6b1f::1)) 56 data bytes

and goes no further. When I try to ping the ip though, it works perfectly. I'm not sure what could be causing this.

networkManager is managing my `/etc/resolve.conf`

# Generated by NetworkManager
search hsd1.il.comcast.net
nameserver 75.75.75.75
nameserver 75.75.76.76
nameserver 2001:558:feed::1
# NOTE: the libc resolver may not support more than 3 nameservers.
# The nameservers listed below may not be recognized.
nameserver 2001:558:feed::2

The issue is that some commands work fine (npm install, pacman -S) but others do not. Pacman -S has an issue where I will get 404 errors for many packages until eventually they install successfully. youtube-dl hangs the same way as ping and stack build gives me the following error:

Preparing to install GHC (tinfo6) to an isolated location.
This will not interfere with any system-level installation.
Preparing to download ghc-tinfo6-8.10.3 ...
Download expectation failure: HttpExceptionRequest Request {
  host                 = "downloads.haskell.org"
  port                 = 443
  secure               = True
  requestHeaders       = [("User-Agent","The Haskell Stack")]
  path                 = "/~ghc/8.10.3/ghc-8.10.3-x86_64-fedora27-linux.tar.xz"
  queryString          = ""
  method               = "GET"
  proxy                = Nothing
  rawBody              = False
  redirectCount        = 10
  responseTimeout      = ResponseTimeoutDefault
  requestVersion       = HTTP/1.1
  proxySecureMode      = ProxySecureWithConnect
}
 ConnectionTimeout

[bold]Update[/bold]
Seems to be an issue with Comcast blocking IPv6 sad. Best solution is to chane dns nameservers to one of the open one's listed below and set IPv4 preference in `/etc/gai.conf`

Last edited by omernaveedxyz (2021-03-27 19:48:01)

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#2 2021-03-26 20:49:50

seth
Member
Registered: 2012-09-03
Posts: 19,799

Re: [Solved] Unable to ping domain names, but ping ip works fine

Looks like the domain is resolved IPv6 - can you ping IPv6 or only IPv4?

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#3 2021-03-26 22:54:42

omernaveedxyz
Member
Registered: 2020-12-31
Posts: 30

Re: [Solved] Unable to ping domain names, but ping ip works fine

seth wrote:

Looks like the domain is resolved IPv6 - can you ping IPv6 or only IPv4?

Seems to be an issue with pinging IPv6. Added IPv4 preference to `/etc/gai.conf` (works fine) but would like a proper solution.

precedence ::ffff:0:0/96 100

Last edited by omernaveedxyz (2021-03-26 22:55:04)

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#4 2021-03-27 06:37:10

seth
Member
Registered: 2012-09-03
Posts: 19,799

Re: [Solved] Unable to ping domain names, but ping ip works fine

What would be a "proper solution"?
Do you expect to have an IPv6 route?

dig @75.75.75.75 archlinux.org

gets me an empty A record and no AAAA record

dig @75.75.75.76 archlinux.org

just times out.

Here's a bunch of public DNS servers that don't suck and are all not Comcast…

OpenDNS
208.67.222.222
208.67.220.220

Cloudflare:
1.1.1.1
1.0.0.1

Google:
8.8.8.8
8.8.4.4

Quad9:
9.9.9.9

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#5 2021-03-27 06:44:56

progandy
Member
Registered: 2012-05-17
Posts: 4,235

Re: [Solved] Unable to ping domain names, but ping ip works fine

seth wrote:
dig @75.75.75.75 archlinux.org

gets me an empty A record and no AAAA record

dig responds to me with "status: REFUSED". Comcast doesn't want others to use it.

seth wrote:
dig @75.75.75.76 archlinux.org

just times out.

The third octet should be 76 as well.

Last edited by progandy (2021-03-27 06:46:26)


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#6 2021-03-27 07:01:39

seth
Member
Registered: 2012-09-03
Posts: 19,799

Re: [Solved] Unable to ping domain names, but ping ip works fine

D'ooh! (Comcast bias blindness, we start by the assumtion that they suck ;-)
Same for .76.76, though this time .75.75 timed out three times before responding again.

@omernaveedxyz
You'll have to dig yourself or just try a public DNS - and elaborate on what you assume a "proper solution" would be.

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#7 2021-03-27 08:05:27

omernaveedxyz
Member
Registered: 2020-12-31
Posts: 30

Re: [Solved] Unable to ping domain names, but ping ip works fine

seth wrote:

D'ooh! (Comcast bias blindness, we start by the assumtion that they suck ;-)
Same for .76.76, though this time .75.75 timed out three times before responding again.

@omernaveedxyz
You'll have to dig yourself or just try a public DNS - and elaborate on what you assume a "proper solution" would be.

Sorry for being general, I meant that I don't believe I should be enabling IPv4 precedence through /etc/gai.conf. I just recently did a clean install and this problem has started occurring. I have switched the comcast dns to cloudflare, but I still get a timeout when I attempt to ping archlinux.org or google.com. I have never had this issue before so I am unfamiliar with the whole topic of dns and resolv.conf in general.

Last edited by omernaveedxyz (2021-03-27 08:08:33)

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#8 2021-03-27 08:11:22

seth
Member
Registered: 2012-09-03
Posts: 19,799

Re: [Solved] Unable to ping domain names, but ping ip works fine

Can you "ping -6 2001:4860:4860::8888"?

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#9 2021-03-27 08:12:59

omernaveedxyz
Member
Registered: 2020-12-31
Posts: 30

Re: [Solved] Unable to ping domain names, but ping ip works fine

seth wrote:

Can you "ping -6 2001:4860:4860::8888"?

No luck.

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#10 2021-03-27 08:21:01

seth
Member
Registered: 2012-09-03
Posts: 19,799

Re: [Solved] Unable to ping domain names, but ping ip works fine

It just means that you don't have IPv6 and your IPS probably doesn't provide it.

To set custom DNS servers in NM see
https://wiki.archlinux.org/index.php/Ne … NS_servers

To disable IPv6 on the system see https://wiki.archlinux.org/index.php/IPv6#Disable_IPv6 and in particular https://wiki.archlinux.org/index.php/IP … kManager_3

And ensure the "search hsd1.il.comcast.net" line doesn't show up anymore.

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