Sonic.net

it seems to be a problem with the Sonic DNS. By default my laptop uses 192.168.0.1, which is the router from Sonic. After switching to the Google DNS (8.8.8.8) Facebook works again

Same problem here, on three different browsers, two operating systems, both wifi & wired. It started pretty suddenly around two weeks ago, and has remained problematic since then.

See also:
http://www.reddit.com/r/facebook/commen ... ve_lately/

mka wrote:it seems to be a problem with the Sonic DNS. By default my laptop uses 192.168.0.1, which is the router from Sonic. After switching to the Google DNS (8.8.8.8) Facebook works again

Thanks! I had not considered DNS issues.

When I lookup http://www.facebook.com with Sonic DNS and Google DNS I get the same CNAME (star.c10r.facebook.com) but two different IP blocks (186.60.216.7 and 31.13.73.*, the Google results appear to rotate within a /24).

I wonder if this is the root cause of the problem? People with other ISPs are reporting similar behavior - maybe there's a widespread DNS caching problem? Filed a support ticket to have this checked into.

mka wrote:it seems to be a problem with the Sonic DNS. By default my laptop uses 192.168.0.1, which is the router from Sonic. After switching to the Google DNS (8.8.8.8) Facebook works again

Just some random observations. Facebook prefers IPv6, if the visitor has it enabled. The Sonic. IPv4 DNS servers (with, or without RPZ enabled) fail DNS at http://test-ipv6.com (I get 9/10). For that last reason, and that Sonic. has no IPv6 DNS servers, I have coded the Google IPv6 DNS servers in my router.

My router doing the lookup:
C:\utils\dig>nslookup www.facebook.com
Server: 1000-0000-0000-0000-09d7-04ed-a420-2062.6rd.ip6.sonic.net
Address: 2602:24a:de40:7d90::1

Non-authoritative answer:
Name: star.c10r.facebook.com
Addresses: 2a03f022:6:face:b00c:0:2
185.60.216.7
Aliases: www.facebook.com

Sonic. RPZ DNS server doing the lookup:
C:\utils\dig>nslookup www.facebook.com 208.201.224.11
Server: ns1.sonic.net
Address: 208.201.224.11

Non-authoritative answer:
Name: star.c10r.facebook.com
Addresses: 2a03f022:6:face:b00c:0:2
185.60.216.7
Aliases: www.facebook.com

Sonic. non-RPZ DNS server doing the lookup:
C:\utils\dig>nslookup www.facebook.com 75.101.19.196
Server: optns1.sonic.net
Address: 75.101.19.196

Non-authoritative answer:
Name: star.c10r.facebook.com
Addresses: 2a03f022:6:face:b00c:0:2
185.60.216.7
Aliases: www.facebook.com

Has anyone found a workaround? I tried using /etc/hosts to remap www.facebook.com to an IP address reported by their official DNS servers, but it didn't help.

forest wrote:Has anyone found a workaround? I tried using /etc/hosts to remap http://www.facebook.com to an IP address reported by their official DNS servers, but it didn't help.

You might also want to flush the browser DNS cache, if it has one.

I'm using Google DNS now and the problem has vanished (for other people I'm in touch with as well, some of whom are not Sonic customers but using other DNS with similar problems). Sonic support's last update was

Everything seems to be fine. I get different results with different carriers but they all appear to be pulling from the same basic source.

It is strange that switching to google dns works out but I can't find any solid reason that is the case. I will do a bit more checking and update you with any info I get.

This doesn't sound like much is likely to change on the Sonic end, so I'll probably just stay with 8.8.8.8/8.8.4.4 going forward unless I hear that changes have occurred that fixed the problem. Whatever the problem actually is.

I think I must have made a mistake in my hurried first attempt at a workaround, because I just tried an /etc/hosts entry again, and it has been working nicely for the past hour.

What I noticed:

My browsers' network monitors showed that although facebook hits about 8 different domain names while loading the content for a page, www.facebook.com is indeed the one that is timing out.

Sonic's DNS is returning this:
www.facebook.com. 3023 IN CNAME star.c10r.facebook.com.
star.c10r.facebook.com. 36 IN A 185.60.216.7

Google's DNS is returning these:
www.facebook.com. 3557 IN CNAME star.c10r.facebook.com.
star.c10r.facebook.com. 3 IN A 31.13.73.{225,241,1,193}

Facebook's DNS is returning this:
star.c10r.facebook.com. 60 IN A 173.252.74.22

I tried an /etc/hosts entry using one of the addresses returned by Google's DNS, and tried it again with the address returned by Facebook's DNS. Both seem to solve the problem. Here's the one I'm currently using: It sure looks like Sonic's DNS servers are returning an incorrect (or stale) address for star.c10r.facebook.com. Why is that?

forest wrote: It sure looks like Sonic's DNS servers are returning an incorrect (or stale) address for star.c10r.facebook.com. Why is that?

We're returning whatever Facebook's servers told us to. The different addresses are most likely to support geographic load balancing. That said, there's lots of people complaining about these problems - not just on sonic connectivity.

kgc wrote:We're returning whatever Facebook's servers told us to.

Well, yes, I would think so. But why is that an address that doesn't work well, and currently differs from what facebook's servers tell me when I query them from within Sonic's network? Maybe it's worth flushing Sonic's DNS cache?

My real point is that *I* have seen these problems over the past couple of weeks on both my Comcast and AT&T connections too.

As for flushing DNS records, there's a low (900 seconds) TTL so it isn't going to make any difference.