SBCGlobal possibly blocking


All of a sudden around noon of 5/31/18, DNS using stopped working (took too long to respond).

I try to access and it doesn’t load.

It has been working fine for the last 60 days.

All I can guess is my ISP Comcast is blocking because they can’t see what I am doing through it or something.

Please let me know if it is a major issue, or just a small issue with me.

Thank you.

If you would like a traceroute sent, who do I email it to? I am not going to post it publicly on this forum.


I have a traceroute from a Comcast-hosted machine, and I’m not seeing any connectivity failures:

% mtr -nrwc 10
Start: Fri Jun  1 00:25:10 2018
HOST: node          Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|--    0.0%    10    0.5   0.5   0.3   0.7   0.0
  2.|--  0.0%    10    9.3   9.1   8.1  10.8   0.6
  3.|--  0.0%    10   16.2  10.8   8.4  16.2   2.8
  4.|--  0.0%    10   11.3  10.5   9.3  11.8   0.6
  5.|--    0.0%    10   12.7  13.1  11.7  14.6   0.7
  6.|--    0.0%    10   11.6  12.2  10.5  15.3   1.4
  7.|--  0.0%    10   12.4  12.8  11.4  15.9   1.2
  8.|--        0.0%    10   10.5  11.1   9.7  14.9   1.4

pings also work for me:

% ping -c 4
PING ( 56(84) bytes of data.
64 bytes from icmp_seq=1 ttl=57 time=12.0 ms
64 bytes from icmp_seq=2 ttl=57 time=16.5 ms
64 bytes from icmp_seq=3 ttl=57 time=10.0 ms
64 bytes from icmp_seq=4 ttl=57 time=11.4 ms

--- ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3001ms
rtt min/avg/max/mdev = 10.090/12.541/16.511/2.404 ms

I think it’s a limited problem, sorry. Can you retry with a different machine on your network?

I would say it could be related to the incident we had earlier today, but that only affected UDP traffic, so that wouldn’t explain why isn’t working.


I don’t think so since Comcast is one of the tell largest ISPs (ir the largest? I don’t know) in the US there would have been more complaints from Comcast users.

Maybe some minor outage or routing issues on the Comcast network or one if their peers.


Run a

tcptraceroute 443

if you are on Linux. (also available for MAC)
This wil show you where the request times out.

We can’t help with a naked screenshot.
A tracerute would help as well. Remove the first two or three HOPs if you are concerned about
the IP addresses or POP names.


I am getting only * * * for each hop.


No change today. Should I contact my ISP?


For each? at which point?


For all 60 hops.


So, the first one as well? Then you better check your network configuration or system firewall.


I have a Windows, a Mac, and an Android (It loads fine on data), none can access

And I realize now, I am running on SBCGlobal, not Comcast. All I can assume is SBCglobal is blocking traffic to It was legit working for 2 months, and it just stopped last week.


Isnt SBC AT&T? There were issues there IIRC - Cannot connect to on AT&T

But, could it be a local issue? Router?!

Can you describe your network setup/topology?


Does the first hip show three * or not? You didn’t answer my question :wink:

If so, please paste the output of

ipconfig /all
route print

Or from your Mac
ip a (or ifconfig)
route -n

It’s hard to say what’s going on there without a trace. We don’t have PMs here unfortunately, even leaders can’t send them.


Yes @sandro
2005, SBC Communications acquired AT&T, then changed its own name to AT&T Inc. Today when you see the address “,” you might be seeing an email address suffix, or a reference to the websites for AT&T or Yahoo!


That was my understanding too and if they share infrastructure, this might be simply the AT&T issue.

However, the AT&T issue is/was AFAIK not a routing one but their modems hijacked the address. I am blurry on the details here though :slight_smile:

One thing that makes me wonder if it isnt a local problem is the fact the trace doesnt show anything at all - not even the first hop(s). On the other hand, given the OP mentioned it started only recently this would rather indicate an external change in configuration/routing, unless of course he swapped his network hardware recently (or some firmware was updated).


Isn’t posting my ifconfig a security vulnerability?

And route -n gives me the commands on mac.

$ route -n
usage: route [-dnqtv] command [[modifiers] args]


Eh. Here you go.

lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
    inet netmask 0xff000000 
    inet6 ::1 prefixlen 128 
    inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 
    nd6 options=201<PERFORMNUD,DAD>
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0<> mtu 1280
XHC20: flags=0<> mtu 0
    ether 78:31:c1:c1:77:2a 
    inet6 fe80::8ed:31ef:dee5:86a4%en0 prefixlen 64 secured scopeid 0x5 
    inet netmask 0xffffff00 broadcast
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect
    status: active
    ether 0a:31:c1:c1:77:2a 
    media: autoselect
    status: inactive
    ether 02:79:00:b4:b6:08 
    inet6 fe80::79:ff:feb4:b608%awdl0 prefixlen 64 scopeid 0x7 
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect
    status: active
    ether 72:00:01:ed:fe:e0 
    media: autoselect <full-duplex>
    status: inactive
    ether 72:00:01:ed:fe:e1 
    media: autoselect <full-duplex>
    status: inactive
    ether 72:00:01:ed:fe:e0 
        id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0
        maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200
        root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0
        ipfilter disabled flags 0x2
    member: en1 flags=3<LEARNING,DISCOVER>
            ifmaxaddr 0 port 8 priority 0 path cost 0
    member: en2 flags=3<LEARNING,DISCOVER>
            ifmaxaddr 0 port 9 priority 0 path cost 0
    nd6 options=201<PERFORMNUD,DAD>
    media: <unknown type>
    status: inactive
utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 2000
    inet6 fe80::9e1f:36b9:4cdd:528%utun0 prefixlen 64 scopeid 0xb 
    nd6 options=201<PERFORMNUD,DAD>


Please tell me if this is not secure.


Neither is your network setup/topology.


OK. And sorry I didn’t clarify. Every single hop was 3 *.

And the router setup is just a simple router connected to my machines.


What kind of router and where is it plugged in?