From: Wallace Keith Sent: Friday, September 21, 2012 11:46 AM To: 'discussion@outages.org' Subject: Comcast blocking ftp? There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location. -Keith
On 21 Sep 2012, at 11:48, Wallace Keith wrote:
There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location.
Not Comcast cable in Monroeville, PA. Comcast business, perhaps? Michael
I'm able to upload and download to/from various FTP servers via comcast in Atlanta. On Fri, Sep 21, 2012 at 11:48 AM, Wallace Keith <kwallace@pcconnection.com> wrote:
From: Wallace Keith Sent: Friday, September 21, 2012 11:46 AM To: 'discussion@outages.org' Subject: Comcast blocking ftp?
There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location.
-Keith
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Same in Colorado. Blake Pfankuch Cisco, Microsoft, Adtran and VMware Certification Information available upon request. -----Original Message----- From: outages-bounces@outages.org [mailto:outages-bounces@outages.org] On Behalf Of Aubrey Wells Sent: Friday, September 21, 2012 9:58 AM To: Wallace Keith Cc: outages@outages.org Subject: Re: [outages] Comcast blocking ftp? I'm able to upload and download to/from various FTP servers via comcast in Atlanta. On Fri, Sep 21, 2012 at 11:48 AM, Wallace Keith <kwallace@pcconnection.com> wrote:
From: Wallace Keith Sent: Friday, September 21, 2012 11:46 AM To: 'discussion@outages.org' Subject: Comcast blocking ftp?
There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location.
-Keith
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On Fri, Sep 21, 2012 at 8:48 AM, Wallace Keith <kwallace@pcconnection.com> wrote:
There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location.
I'm on Comcast residential right now, and I can get to external FTP services just fine. Do you have some specifics I could try?
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 If this not outage related kindly move this thread to outages-discussion@ regards, /virendra -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://www.enigmail.net/ iF4EAREIAAYFAlBckVIACgkQ3HuimOHfh+FvogD+KKpRIRwXn45U7ORu8Gy4EswW TfgUy1HX817VEUazUG4A/20HJ55gyJ7+4vYblHZ8tMjyioROE6pg+qWl+4vQMy+i =ON8l -----END PGP SIGNATURE-----
Are you talking about outbound FTP (e.g. client on Comcast trying to FTP to a server on the Internet), or are you talking about inbound FTP (e.g. client on the Internet trying to FTP to a server hosted on a Comcast residential connection)? The direction matters. 1. Comcast does not filter outbound FTP requests (Comcast->Internet) 2. Comcast does not usually filter inbound FTP requests (Internet->Comcast), however if the customer is a residential customer this is not permitted per TOS). If the customer is commercial/business then no filtering is done. In the case of a residential customer hosting a server, if Comcast finds this, they usually deploy filtering at the cable modem level (by pushing out an updated cable modem config to the customer which is picked up via TFTP + rebooting the modem remotely). There is no way around this aside from talking to Comcast on the phone or moving the server to another port (which is not advisable on residential connections as Comcast would probably terminate service in this situation). I can confirm on residential connections that *normally* Comcast does permit inbound FTP traffic reaching the customer. Below is from tcpdump on my router (on Comcast), where the client is trying to connect to my Comcast IP on TCP port 21. As you can see, the SYN does arrive: 09:05:49.737352 IP 209.126.140.25.57088 > 67.180.84.87.21: Flags [S], seq 31607697, win 65535, options [mss 1460,nop,wscale 6,sackOK,TS val 3722921725 ecr 0], length 0 -- | Jeremy Chadwick jdc@koitsu.org | | UNIX Systems Administrator http://jdc.koitsu.org/ | | Mountain View, CA, US | | Making life hard for others since 1977. PGP 4BD6C0CB | On Fri, Sep 21, 2012 at 11:48:42AM -0400, Wallace Keith wrote:
From: Wallace Keith Sent: Friday, September 21, 2012 11:46 AM To: 'discussion@outages.org' Subject: Comcast blocking ftp?
There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location.
-Keith
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FTP clients working fine via IPv4 from Comcast residential in both Mountain View, CA and Salt Lake City, UT. Only passive mode tested. Testing from off-net to Comcast IPv4 port 21 in SLC shows the SYN made it, and RST was generated by my host. Perhaps if there is a block on servers, it's selective (heavy user, etc). They're not blocking me. On Sep 21, 2012, at 8:48, Wallace Keith <kwallace@pcconnection.com> wrote:
From: Wallace Keith Sent: Friday, September 21, 2012 11:46 AM To: 'discussion@outages.org' Subject: Comcast blocking ftp?
There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location.
-Keith
_______________________________________________ Outages mailing list Outages@outages.org https://puck.nether.net/mailman/listinfo/outages
This sounds like a "comcast sucks, my ftp isnt working, maybe comcast is blocking it" On Fri, Sep 21, 2012 at 12:16 PM, Kevin Blackham <blackham@gmail.com> wrote:
FTP clients working fine via IPv4 from Comcast residential in both Mountain View, CA and Salt Lake City, UT. Only passive mode tested.
Testing from off-net to Comcast IPv4 port 21 in SLC shows the SYN made it, and RST was generated by my host.
Perhaps if there is a block on servers, it's selective (heavy user, etc). They're not blocking me.
On Sep 21, 2012, at 8:48, Wallace Keith <kwallace@pcconnection.com> wrote:
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*From:* Wallace Keith *Sent:* Friday, September 21, 2012 11:46 AM *To:* 'discussion@outages.org' *Subject:* Comcast blocking ftp?****
** **
There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location.* ***
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-Keith****
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Thanks for all the replies, didn't mean to cry wolf. I don't have Comcast at my location so I cannot test. We'll have to look elsewhere for the cause. From: outages-bounces@outages.org [mailto:outages-bounces@outages.org] On Behalf Of Wallace Keith Sent: Friday, September 21, 2012 11:49 AM To: outages@outages.org Subject: [outages] Comcast blocking ftp? From: Wallace Keith Sent: Friday, September 21, 2012 11:46 AM To: 'discussion@outages.org' Subject: Comcast blocking ftp? There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location. -Keith
Here is a list of ports we do block on both residential and commercial services over DOCSIS services: http://customer.comcast.com/help-and-support/internet/list-of-blocked-ports/ http://businesshelp.comcast.com/help-and-support/internet/ports-blocked-by-b... We do not block FTP. Thanks -- Chris Griffiths Comcast Cable Communications, Inc. National Engineering and Technical Operations On Sep 21, 2012, at 1:54 PM, Wallace Keith <kwallace@pcconnection.com<mailto:kwallace@pcconnection.com>> wrote: Thanks for all the replies, didn’t mean to cry wolf. I don’t have Comcast at my location so I cannot test. We’ll have to look elsewhere for the cause. From: outages-bounces@outages.org<mailto:outages-bounces@outages.org> [mailto:outages-bounces@outages.org<mailto:bounces@outages.org>] On Behalf Of Wallace Keith Sent: Friday, September 21, 2012 11:49 AM To: outages@outages.org<mailto:outages@outages.org> Subject: [outages] Comcast blocking ftp? From: Wallace Keith Sent: Friday, September 21, 2012 11:46 AM To: 'discussion@outages.org<mailto:discussion@outages.org>' Subject: Comcast blocking ftp? There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location. -Keith _______________________________________________ Outages mailing list Outages@outages.org<mailto:Outages@outages.org> https://puck.nether.net/mailman/listinfo/outages
Apologies for the double post. My mail client went bonkers. Thanks -- Chris Griffiths Comcast Cable Communications, Inc. National Engineering and Technical Operations On Sep 24, 2012, at 2:57 PM, "Griffiths, Chris" <Chris_Griffiths@Cable.Comcast.com<mailto:Chris_Griffiths@Cable.Comcast.com>> wrote: Here is a list of ports we do block on both residential and commercial services over DOCSIS services: http://customer.comcast.com/help-and-support/internet/list-of-blocked-ports/ http://businesshelp.comcast.com/help-and-support/internet/ports-blocked-by-b... We do not block FTP. Thanks -- Chris Griffiths Comcast Cable Communications, Inc. National Engineering and Technical Operations On Sep 21, 2012, at 1:54 PM, Wallace Keith <kwallace@pcconnection.com<mailto:kwallace@pcconnection.com>> wrote: Thanks for all the replies, didn’t mean to cry wolf. I don’t have Comcast at my location so I cannot test. We’ll have to look elsewhere for the cause. From: outages-bounces@outages.org<mailto:outages-bounces@outages.org> [mailto:outages-bounces@outages.org<mailto:bounces@outages.org>] On Behalf Of Wallace Keith Sent: Friday, September 21, 2012 11:49 AM To: outages@outages.org<mailto:outages@outages.org> Subject: [outages] Comcast blocking ftp? From: Wallace Keith Sent: Friday, September 21, 2012 11:46 AM To: 'discussion@outages.org<mailto:discussion@outages.org>' Subject: Comcast blocking ftp? There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location. -Keith _______________________________________________ Outages mailing list Outages@outages.org<mailto:Outages@outages.org> https://puck.nether.net/mailman/listinfo/outages _______________________________________________ Outages mailing list Outages@outages.org<mailto:Outages@outages.org> https://puck.nether.net/mailman/listinfo/outages
I can honestly say that all the ports blocked on that list have a legitimate reason. Kudos to Comcast for actually caring. On Mon, Sep 24, 2012 at 3:07 PM, Griffiths, Chris < Chris_Griffiths@cable.comcast.com> wrote:
Apologies for the double post. My mail client went bonkers.
Thanks -- Chris Griffiths Comcast Cable Communications, Inc. National Engineering and Technical Operations
On Sep 24, 2012, at 2:57 PM, "Griffiths, Chris" < Chris_Griffiths@Cable.Comcast.com> wrote:
Here is a list of ports we do block on both residential and commercial services over DOCSIS services:
http://customer.comcast.com/help-and-support/internet/list-of-blocked-ports/
http://businesshelp.comcast.com/help-and-support/internet/ports-blocked-by-b...
We do not block FTP.
Thanks -- Chris Griffiths Comcast Cable Communications, Inc. National Engineering and Technical Operations
On Sep 21, 2012, at 1:54 PM, Wallace Keith <kwallace@pcconnection.com> wrote:
Thanks for all the replies, didn’t mean to cry wolf. I don’t have Comcast at my location so I cannot test.**** We’ll have to look elsewhere for the cause.****
*From:* outages-bounces@outages.org [mailto:outages-bounces@outages.org] *On Behalf Of *Wallace Keith *Sent:* Friday, September 21, 2012 11:49 AM *To:* outages@outages.org *Subject:* [outages] Comcast blocking ftp?**** ** **
*From:* Wallace Keith *Sent:* Friday, September 21, 2012 11:46 AM *To:* 'discussion@outages.org' *Subject:* Comcast blocking ftp?**** ** ** There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location.* *** ** ** -Keith**** ** ** ** ** _______________________________________________ Outages mailing list Outages@outages.org https://puck.nether.net/mailman/listinfo/outages
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Here is a list of ports we do block on both residential and commercial services over DOCSIS services: http://customer.comcast.com/help-and-support/internet/list-of-blocked-ports/ http://businesshelp.comcast.com/help-and-support/internet/ports-blocked-by-b... We do not block FTP. Thanks -- Chris Griffiths Comcast Cable Communications, Inc. National Engineering and Technical Operations On Sep 21, 2012, at 1:54 PM, Wallace Keith <kwallace@pcconnection.com<mailto:kwallace@pcconnection.com>> wrote: Thanks for all the replies, didn’t mean to cry wolf. I don’t have Comcast at my location so I cannot test. We’ll have to look elsewhere for the cause. From: outages-bounces@outages.org<mailto:outages-bounces@outages.org> [mailto:outages-bounces@outages.org<mailto:bounces@outages.org>] On Behalf Of Wallace Keith Sent: Friday, September 21, 2012 11:49 AM To: outages@outages.org<mailto:outages@outages.org> Subject: [outages] Comcast blocking ftp? From: Wallace Keith Sent: Friday, September 21, 2012 11:46 AM To: 'discussion@outages.org<mailto:discussion@outages.org>' Subject: Comcast blocking ftp? There is an ongoing discussion in the citizens weather observer community that ftp might be being blocked by Comcast? Can anyone confirm this is really the case? Allegedly started at 6:30am today. Sorry I cannot provide technical examples. I do not have Comcast at my current location. -Keith _______________________________________________ Outages mailing list Outages@outages.org<mailto:Outages@outages.org> https://puck.nether.net/mailman/listinfo/outages
participants (11)
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Aubrey Wells -
Blake Pfankuch -
Brian Henson -
chris -
Griffiths, Chris -
Jeremy Chadwick -
Kevin Blackham -
Michael Acosta -
Michael H Lambert -
virendra rode -
Wallace Keith