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

omernaveedxyz · 2021-03-26 18:53:01

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 . 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)

seth · 2021-03-26 20:49:50

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

omernaveedxyz · 2021-03-26 22:54:42

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)

seth · 2021-03-27 06:37:10

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

progandy · 2021-03-27 06:44:56

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)

seth · 2021-03-27 07:01:39

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.

omernaveedxyz · 2021-03-27 08:05:27

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)

seth · 2021-03-27 08:11:22

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

omernaveedxyz · 2021-03-27 08:12:59

seth wrote:

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

No luck.

seth · 2021-03-27 08:21:01

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.

Arch Linux

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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