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Standard User jefferson
(newbie) Wed 07-May-14 13:17:07
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"Self healing" - How does it work at the network level


[link to this post]
 
Does anyone know how the self-healing "feature" works at a network level? I know it cannot be easily disabled but I need to bypass it somehow. My WAN connection is fine (can ping, resolve DNS, ssh out etc) but the stupid router insists there is a problem and is redirecting all outbound tcp/80 connections to its "self healing" pages...

$ curl -v google.com
* Rebuilt URL to: google.com/
* Adding handle: conn: 0xcd5860
* Adding handle: send: 0
* Adding handle: recv: 0
* Curl_addHandleToPipeline: length: 1
* - Conn 0 (0xcd5860) send_pipe: 1, recv_pipe: 0
* About to connect() to google.com port 80 (#0)
* Trying 173.194.34.71...
* Connected to google.com (173.194.34.71) port 80 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.32.0
> Host: google.com
> Accept: */*
>
< HTTP/1.1 302 temporary redirect
< Location: http://192.168.1.1/sky_self_heal.html

* no chunk, no close, no size. Assume close to signal end
<
Content-Type: text/html

* Closing connection 0


Proof that the connection is ok, https works a charm...

$ curl -v https://google.com
* Rebuilt URL to: https://google.com/
* Adding handle: conn: 0x14dc860
* Adding handle: send: 0
* Adding handle: recv: 0
* Curl_addHandleToPipeline: length: 1
* - Conn 0 (0x14dc860) send_pipe: 1, recv_pipe: 0
* About to connect() to google.com port 443 (#0)
* Trying 173.194.34.69...
* Connected to google.com (173.194.34.69) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* CAfile: /etc/pki/tls/certs/ca-bundle.crt
CApath: none
* SSL connection using TLS_RSA_WITH_RC4_128_SHA
* Server certificate:
* subject: CN=*.google.com,O=Google Inc,L=Mountain View,ST=California,C=US
* start date: Apr 23 12:16:09 2014 GMT
* expire date: Jul 22 00:00:00 2014 GMT
* common name: *.google.com
* issuer: CN=Google Internet Authority G2,O=Google Inc,C=US
> GET / HTTP/1.1
> User-Agent: curl/7.32.0
> Host: google.com
> Accept: */*
>
< HTTP/1.1 302 Found
< Cache-Control: private
< Content-Type: text/html; charset=UTF-8
< Location: https://www.google.co.uk/?gfe_rd=cr&ei=6iJqU5vBBY3R8...
< Content-Length: 262
< Date: Wed, 07 May 2014 12:11:22 GMT
* Server GFE/2.0 is not blacklisted
< Server: GFE/2.0
< Alternate-Protocol: 443:quic
<
<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>302 Moved</TITLE></HEAD><BODY>
<H1>302 Moved</H1>
The document has moved
<A HREF="https://www.google.co.uk/?gfe_rd=cr&amp;ei=6iJqU5vBBY3R8gf4h4DQBQ">here</A>.
</BODY></HTML>
* Connection #0 to host google.com left intact


Ive tried rebooting the router but no improvement. Tempted to just dig a spare router out but dont really want to deal with having to hack all the settings out of the sky one. Its been working fine since joining sky a few months ago.

Jeffers
Standard User Oliver341
(eat-sleep-adslguide) Wed 07-May-14 14:01:00
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Re: "Self healing" - How does it work at the network level


[re: jefferson] [link to this post]
 
Have you tried a factory reset?

Oliver.
Standard User hypertony
(experienced) Wed 07-May-14 14:19:03
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Re: "Self healing" - How does it work at the network level


[re: jefferson] [link to this post]
 
Do you have admin access to the Sky router? If so there should be a setting to disable it.

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Standard User Oliver341
(eat-sleep-adslguide) Wed 07-May-14 15:31:40
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Re: "Self healing" - How does it work at the network level


[re: hypertony] [link to this post]
 
In reply to a post by hypertony:
Do you have admin access to the Sky router? If so there should be a setting to disable it.

There isn't. But I suspect a factory reset would correct the issue.

Oliver.
Standard User jefferson
(newbie) Wed 07-May-14 17:48:06
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Re: "Self healing" - How does it work at the network level


[re: Oliver341] [link to this post]
 
Another reboot seems to have cured it, for now at least.

Does anyone know how it actually works? I'm a little concerned that the router is doing some kind of port-based redirects for outbound traffic. I understand it could be useful for some but there should at least be an option to disable it.
Standard User Oliver341
(eat-sleep-adslguide) Wed 07-May-14 18:23:07
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Re: "Self healing" - How does it work at the network level


[re: jefferson] [link to this post]
 
In my experience, when the line drops, the router spoofs all DNS queries to a local IP address which is then answered by the router and in turn displays the self heal pages. When the connection comes back up, the DNS queries are answered as normal.

I don't think it's any more intrusive than that.

Oliver.
Standard User jefferson
(newbie) Wed 07-May-14 18:29:54
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Re: "Self healing" - How does it work at the network level


[re: Oliver341] [link to this post]
 
In reply to a post by Oliver341:
In my experience, when the line drops, the router spoofs all DNS queries to a local IP address which is then answered by the router and in turn displays the self heal pages. When the connection comes back up, the DNS queries are answered as normal.

I don't think it's any more intrusive than that.


I dont think it is DNS based:

$ curl -v google.com
* Rebuilt URL to: google.com/
* Adding handle: conn: 0xcd5860
* Adding handle: send: 0
* Adding handle: recv: 0
* Curl_addHandleToPipeline: length: 1
* - Conn 0 (0xcd5860) send_pipe: 1, recv_pipe: 0
* About to connect() to google.com port 80 (#0)
* Trying 173.194.34.71...
* Connected to google.com (173.194.34.71) port 80 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.32.0
> Host: google.com
> Accept: */*
>
< HTTP/1.1 302 temporary redirect
< Location: http://192.168.1.1/sky_self_heal.html
* no chunk, no close, no size. Assume close to signal end
<
Content-Type: text/html

* Closing connection 0
Standard User Oliver341
(eat-sleep-adslguide) Wed 07-May-14 18:37:30
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Re: "Self healing" - How does it work at the network level


[re: jefferson] [link to this post]
 
That result must be cached. It's impossible to look up a DNS entry without an internet connection.

Oliver.
Standard User jefferson
(newbie) Thu 08-May-14 16:34:35
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Re: "Self healing" - How does it work at the network level


[re: Oliver341] [link to this post]
 
In reply to a post by Oliver341:
That result must be cached. It's impossible to look up a DNS entry without an internet connection.


Thats the whole problem - the internet connection was up.
Standard User Oliver341
(eat-sleep-adslguide) Thu 08-May-14 16:59:59
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Re: "Self healing" - How does it work at the network level


[re: jefferson] [link to this post]
 
In reply to a post by jefferson:
Thats the whole problem - the internet connection was up.

There must be two modes of self heal operation then, a DNS spoof when the IP address is unknown and unable to be obtained, and a port 80 intercept and redirect when the IP address is known.

As you rightly say, this should only ever happen when the internet connection is lost. Personally I've never seen this unless the connection is down, so I'd still recommend a factory reset, especially if it re-occurs.

Oliver.
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