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"Cannot Connect to Server" Issue

Contributor

"Cannot Connect to Server" Issue

While I was on the website, http://forum.m1911.org, I thought the website went down.  After contacting the owner, apparently the website is fine.

 

I was able to connect through my cellular internet devices, but not through my Comcast internet, which has an Arris cable modem,  and then through an Apple Airport wireless router.  I've restarted both the modem and router a few times with no success.

Further research shows various people and services have come across this problem with no clear solution to me.

 

In some of my research, somebody mentioned DNS servers.  I'm not terribly internet/network savvy.  If changing a "DNS" address is required, I don't know how to do that, should that be the solution.  My two listed DNS servers are 75.75.75.75 and 75.75.76.76.

 

Yes, I've already tried disabling firewall settings and antivirus settings.  This website used to work for me for years.  As I said, it does work using my cellular internet methods.  Thanks in advance and I'll come back and post should any clear remedy works.

New Poster

Re: "Cannot Connect to Server" Issue

http://forum.m1911.org/ is reachable for me.
 
What Operating system are you using? I would like to see if flushing your DNS cache or changing the DNS servers would help at all.
Contributor

Re: "Cannot Connect to Server" Issue

I'm using the latest operating systems on iPhone, iPad, Mac (OS 10.10), and a smart Sharp television.  All cannot connect through my wifi at home.  The iPad and iPhone work going through my cellular provider, but not through Comcast & wifi.  It was working a couple of days ago while I was on that actual website, then went down as I was on it!

 

I wouldn't know how to flush a DNS cache.


WurdNerd wrote:
http://forum.m1911.org/ is reachable for me.
 
What Operating system are you using? I would like to see if flushing your DNS cache or changing the DNS servers would help at all.

 

New Poster

Re: "Cannot Connect to Server" Issue

Alright, what kind of Router do you have in your home?

Contributor

Re: "Cannot Connect to Server" Issue

I'm using an Apple AirPort Extreme.

 

I see in my AirPort Extreme where I can change the DNS servers, but what numbers/addresses would I try?  These seem to automatically get filled in my Comcast.

New Poster

Re: "Cannot Connect to Server" Issue

Okay, please follow the instructions on this link here: http://www.macinstruct.com/node/447

You will want to set the DNS to 8.8.8.8 and 8.8.4.4 on your router, then try again.

Contributor

Re: "Cannot Connect to Server" Issue


WurdNerd wrote:

Okay, please follow the instructions on this link here: http://www.macinstruct.com/node/447

You will want to set the DNS to 8.8.8.8 and 8.8.4.4 on your router, then try again.


I changed the DNS addresses (thanks for showing me) and I'm still unable to connect to that website.  The router restarted, I turned wifi off on my computer temporarily, and I quit and restarted Safari, without successSmiley Sad

New Poster

Re: "Cannot Connect to Server" Issue

What's the exact web address you're typing in?

Contributor

Re: "Cannot Connect to Server" Issue


WurdNerd wrote:

What's the exact web address you're typing in?


forum.m1911.org or http://forum.m1911.org

What I haven't tried yet is bypassing the wifi AirPort Extreme router.  I may try that in the next hour...

Expert

Re: "Cannot Connect to Server" Issue

Perhaps a trace route to it may reveal a clue ? I can browse to the site here in northern NJ. Here is a trace from my end as a sample;

 

Tracing route to forum.m1911.org [199.79.199.45]
over a maximum of 30 hops:

 

1 1 ms 1 ms 1 ms 192.168.1.1
2 44 ms 28 ms 14 ms 76.117.136.1
3 24 ms 12 ms 9 ms 68.85.116.233
4 22 ms 11 ms 10 ms ae-1-0-sur01.union.nj.panjde.comcast.net [68.85.
35.18]
5 12 ms 12 ms 12 ms ae-10-0-ar03.plainfield.nj.panjde.comcast.net [6
8.85.62.1]
6 15 ms 15 ms 15 ms he-3-10-0-0-cr01.newyork.ny.ibone.comcast.net [6
8.86.93.225]
7 20 ms 19 ms 19 ms be-10002-cr01.ashburn.va.ibone.comcast.net [68.8
6.86.233]
8 18 ms 19 ms 18 ms he-0-10-0-0-pe07.ashburn.va.ibone.comcast.net [6
8.86.83.66]
9 20 ms 21 ms 18 ms as20115-1-c.ashburn.va.ibone.comcast.net [75.149
.231.210]
10 * * * Request timed out.
11 * * * Request timed out.
12 * * * Request timed out.
13 * * * Request timed out.
14 * * * Request timed out.
15 * * * Request timed out.
16 31 ms 29 ms 29 ms 66-189-1-158.static.oxfr.ma.charter.com [66.189.
1.158]
17 29 ms 28 ms 28 ms lci-gw12-e0a.lightband.net [216.129.147.162]
18 31 ms 30 ms 36 ms gnat.lightband.com [216.129.148.2]
19 30 ms 30 ms 29 ms forum.m1911.org [199.79.199.45]

 

Trace complete.

 

Mine completes to the destination server.



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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New Poster

Re: "Cannot Connect to Server" Issue

Do you have a windows computer in your home?

Contributor

Re: "Cannot Connect to Server" Issue

I don't have a Windows computer, at the moment.  My wife will come home with one, but not until several hours from now.

I don't know how to do a "trace route".

When I bypass the AirPort, I'll hardwire connect directly into my Sharp smart TV, however.

 

PARTIAL SUCCESS!  My Sharp TV, directly connected to the ARRIS cable modem connects right to the website!

Somehow, that would indicate the Apple AirPort extreme/Safari/Mac computer, iPad, & iPhone is blocking the website, even though the iPhone & iPad are unblocked when going through cellular.

 

I understand if any of you decide to drop out at this point as it doesn't seem to be a Comcast issue, anymore.  I don't know if the AirPort has some means of resetting other than unplugging it, however.

Expert

Re: "Cannot Connect to Server" Issue

[Edit]

 

Withdrawn. No longer relevant.



I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
Contributor

Re: "Cannot Connect to Server" Issue

Update.  I reset and reinstalled the Apple AirPort Extreme router and that website still can't be found.

I give up for now.  I can still access that website via cellular so that's good enough.  Thank you everybody.

Contributor

Re: "Cannot Connect to Server" Issue

Update:  I found a possible answer on Apple's forums.  The "why" is over-my-head.  Shutting down my cable modem, Airport Express wireless router, and, for good measure, my extender and computer for ~12 hours fixed the issue.

 

A person on the Apple forum believed the hosting website's service blocked my IP address.  By shutting down for a certain time period solved the issue.  By shutting down for a time, a new IP address is then generated upon restart and I can now get to my problem website.  How long to shut down?  There were suggestions from 2 hours to 2 days.  I tried ~12 hours as I just shut everything down for the night.  Any degree of resetting and restarting did not help.  The system had to be shut down, mainly cable modem and router.  I don't know if the extender and computer had to be shut down, too, or not.

 

It's lengthy, but here's the quote from the Apple.com forums:

 

For those of you who are having this problem, I thought that I would chime in explain what is going on here. First, and foremost, I'm a network engineer who has seen this issue countless times and, surprisingly, the problem is not what a lot of people think it is (although it may seem like it is the case). I'll try to explain this in laymans terms.

 

First, the issue isn't necessarily the AEBS, although it is apart of the problem. What is actually happening here is that you are being blocked by the site, not the other way around. Specifically, your IP address is being "banned" by the site in question (in some cases, temporarily, in others, more permanently). Issues like these are hard to diagnose because most people troubleshoot the issue by unplugging their router, plugging their computer straight into the modem, and then realizing that the issue is gone. Likewise, many people take their routers (in this case, AEBS) to Apple, plug it in, and it starts to work as well. So, let's break this into two parts and address the problem first and why it is happening.

 

The Problem:

As stated above, the issue is happening because of your IP address being banned by the site you are trying to visit. The reason why you are being banned is a combination of a couple of things on both the sites' side and your side, creating a "perfect storm" if you will. From the sites side of the house, around 2008, many linux-based servers started receiving updates that included security products that would detect rapid or repeated connection attempts (products such as fail2ban and csf). When these security products detect rapid connection attempts or repeated failures, they either temporarily or permanently ban the IP address in question. By the end of 2009, many popular web hosting services and control panel companies included these products as well (control panel companies such as CPanel). The problem is that many people do not know that these products are installed on their servers, let alone that they are running (larger entities do, but the smaller shops and individual site owners rarely do). From the user side of the house, around 2008, many browsers started to include HTML5 capabilities through optional software (such as Google Gears). By 2009, most browsers in some way, shape, or form, started to support HTML5 with its ability to do intelligent caching and DB storage in the browser itself. And, this is where we have the problem. Modern day browsers, in an attempt to make our browsing experience better, tend to open multiple connections to servers so that we can browse the site. For sites that have multimedia, photos, tons of links, etc, (such as blogs, video or photo sharing sites, etc) this results in your browser opening hundreds of connections at once. The problem with this is that if the server you are accessing has systems such as csf installed and you attempt to open a ton of threads to the page, the result is that the software mistakenly thinks that you are a security problem and bans your IP address from accessing the site. For most software (such as CSF), the ban is temporary, but increases in time the more you are banned. For other software, the ban could be permanent.

 

Why Changing Routers or Plugging in Directly Works:

The reason why changing routers, plugging in your computer directly to your modem, or even taking in your router back to Apple works is because the minute you do any of those things, your IP address changes. This is because most ISPs link the IP address that you are given to your MAC address. Once the MAC address changes (you changing routers, plugging in directly, etc), your ISP will give you a new IP address. When you plug back in your original router, your ISP will return the IP address that you previously had (in most cases. Sometimes, it will give you a completely new address again).

 

Why this issue is more common with the AEBS than other routers:

In general, this issue is more common with the AEBS (along with cheaper routers) is because the AEBS (along with cheaper routers) generally do not contain QoS (quality of service) controls. Now, for those of you who are technical, you may note that QoS's purpose isn't about preventing you from being banned. And, that is true. For those of you who are not technical, QoS is a process by which your internet bandwidth is regulated by your router so that higher priority items (such as a VoIP phone or a video game) can have more bandwidth available to them when multiple devices are trying to access the Internet at the same time. The reasons why routers with QoS do not experience this issue as often (if ever) is because one of the things that they do is rate and thread limiting. Because your throughput rate and threads are distributed more evenly (rather than a free for all), chances are you will not experience the issue since products like csf work by detecting uneven or rapid connections.

 

Conclusion:

So, in conclusion, 99% of the time, you are being blocked on the other end. To solve the issue, you generally will have to contact the site owner to have your IP address unblocked. If you are using AEBS, the best thing to do would be to disconnect your AEBS from your internet connection for 24 hours and then plug it back in (most ISPs will assign you a new IP if you are offline for 24 hours or more). Also, try to limit the number of tabs that you open to the same site. If you are being blocked by your own site (and, your site uses CPanel, which it likely does), go into your CPanel settings (WHM settings) (from another connection, of course), go to CSF, remove the ban on your IP address, and add it to the exclusion list.

Expert

Re: "Cannot Connect to Server" Issue


L-2 wrote:

Update:  I found a possible answer on Apple's forums.  The "why" is over-my-head.  Shutting down my cable modem, Airport Express wireless router, and, for good measure, my extender and computer for ~12 hours fixed the issue.

 


Good to hear. Basically you were lucky that your WAN / public IP got re-assigned. Comcast's DHCP IP address's are sort of known as being *sticky* dynamic and are tied to the MAC address of the device that is connected directly to the LAN port of the cable modem which means that they can change but are typically re-assigned even after an extended period of time that the modem is off-line. Your old IP must have been needed somewhere else and got withdrawn back in to the IP pool. I've had the same WAN / public IP for more than two years even after having the modem un-plugged for a month on vacation.
FYI. You could have gotten an instant change of public IP address by cloning a different MAC address in to your router's MAC address cloning feature. Keep this in mind for the future. :-)

 

 



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We ask that you post publicly so people with similar questions may benefit from the conversation.
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