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Plusnet blocking udp to port 80

shepthedog
Newbie
Posts: 4
Registered: 09-09-2015

Plusnet blocking udp to port 80

Do pusnet block incoming udp on port 80 from outside of plusnets network.
I am having problems getting a list of computers to access remotely on a home based server. http ones are ok, but udp assigned ones do not show up unless they are also using plusnet as an isp.
Members area firewall has been turned off and router rebooted
This is not a PORT forwarding issue on my router or server.
Any suggestions ?
Thanks
12 REPLIES
Superuser
Superuser
Posts: 11,880
Thanks: 3,243
Fixes: 22
Registered: 22-08-2007

Re: Plusnet blocking udp to port 80

Hi shepthedog,
A warm welcome to the forums.  Whilst I do not have an answer to your question, may I clarify your scenario?
At 'home' you have a server on which you are running a service on port 80 to which you want 'external' machines to connect to.
Either by port forwarding or putting that machine into the DMZ any machine can connect to the server on port 80 using http, regardless of the ISP
Any machine connected on / to the PlusNET network can also connect using udp
All machines outwith the PlusNET network cannot connect using udp with any non-PlusNET ISP.
Do you have a list of the other ISPs please?  It would be interesting to see if there is a virtual ISP involved for which PlusNET is the privider, for example John Lewis.
shepthedog
Newbie
Posts: 4
Registered: 09-09-2015

Re: Plusnet blocking udp to port 80

Answers in Quote  Thanks
One that can connect and I know uses plusnets network is One2Call
,
Ones that cannot include BT both Home and Business Broadband, TalkTalk and Virgin Media. They can connect on these networks if they are configured to use UDP port 8008
Thanks
Si
dick:quote
Community Veteran
Posts: 5,109
Thanks: 465
Fixes: 17
Registered: 10-06-2010

Re: Plusnet blocking udp to port 80

I just tried an online port checker. UDP packets to ports 8008 and also 53 were logged by the firewall when testing those ports. Nothing was logged when testing UDP port 80, as if the UDP packets did not reach my router. So it does look like they're being blocked somewhere.
Doing traceroutes from external hosts, to UDP port 80 on Plusnet hosts, might show where they're being blocked.
Community Gaffer
Community Gaffer
Posts: 13,282
Thanks: 1,051
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Registered: 04-04-2007

Re: Plusnet blocking udp to port 80

Quote from: ejs
Doing traceroutes from external hosts, to UDP port 80 on Plusnet hosts, might show where they're being blocked.

This would certainly help.
I don't have access to an off-network Linux device at the moment, but if anybody does then I'd be interested to see the output from:
$ traceroute -U -p 80 <plusnet customer's IP address>

Edit: edited to include -U switch.

Bob Pullen
Plusnet Product Team
If I've been helpful then please give thanks ⤵

Community Veteran
Posts: 1,136
Thanks: 2
Registered: 30-07-2007

Re: Plusnet blocking udp to port 80

adw@avatastic:~$ traceroute -U -p 80 84.92.xx.xx
traceroute to 84.92.xx.xx (84.92.xx.xx), 30 hops max, 60 byte packets
1  213-138-103-3.no-reverse-dns-set.uk0.bigv.io (213.138.103.3)  3.175 ms  3.133 ms  3.061 ms
2  te3-4.cr2.man.bytemark.co.uk (91.223.58.64)  0.573 ms  0.736 ms  0.815 ms
3  te0-0-2-0.cr1.lon.bytemark.co.uk (91.223.58.34)  7.288 ms  7.485 ms  7.507 ms
4  * * *
5  * * *
6  * * *
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25  * * *
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29  * * *
30  * * *

edited
F9 member since 4 Sep 1999
F9 ADSL customer since 27 Aug 2004
DLM manages your line the same way DRM manages your rights.
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Community Gaffer
Community Gaffer
Posts: 13,282
Thanks: 1,051
Fixes: 86
Registered: 04-04-2007

Re: Plusnet blocking udp to port 80

Hmmm, that's not indicative of any blocking Huh

Bob Pullen
Plusnet Product Team
If I've been helpful then please give thanks ⤵

Community Veteran
Posts: 5,109
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Registered: 10-06-2010

Re: Plusnet blocking udp to port 80

That route is going via bytemark and lonap to Plusnet. Most external traffic to/from Plusnet seems to go through bt.net these days. The port checking website I used was http://www.base64online.com/ . I don't have any external hosts to do traceroutes from either.
Community Veteran
Posts: 1,136
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Registered: 30-07-2007

Re: Plusnet blocking udp to port 80

From a different host.
andy@mc:~$ traceroute -U -p 80 84.92.x.x
traceroute to 84.92.x.x (84.92.x.x), 30 hops max, 60 byte packets
1  10.0.0.1 (10.0.0.1)  0.385 ms  0.364 ms  0.357 ms
2  * * *
3  * * *
4  stn3-edge-02.inet.qwest.net (65.122.30.1)  1.530 ms 8-1-21.ear3.Washington1.Level3.net (4.79.22.93)  1.276 ms  1.505 ms
5  dcp-brdr-03.inet.qwest.net (205.171.251.106)  2.439 ms * *
6  * 166-49-169-109.eu.bt.net (166.49.169.109)  2.538 ms  2.536 ms
7  ae-44-44.ebr2.London1.Level3.net (4.69.137.77)  74.223 ms  74.212 ms t2c3-xe-11-0-0-0.uk-lof.eu.bt.net (166.49.208.52)  82.913 ms
8  213.137.183.39 (213.137.183.39)  87.361 ms ae-56-221.csw2.London1.Level3.net (4.69.153.130)  74.186 ms 213.137.183.33 (213.137.183.33)  81.662 ms
9  ae-227-3603.edge3.London1.Level3.net (4.69.166.154)  74.445 ms core3-te0-17-0-0.faraday.ukcore.bt.net (62.6.201.166)  82.200 ms ae-227-3603.edge3.London1.Level3.net (4.69.166.154)  74.182 ms
10  acc2-10GigE-0-4-0-10.l-far.21cn-ipp.bt.net (109.159.249.134)  82.482 ms BT-NET.edge3.London1.Level3.net (195.50.124.70)  74.479 ms acc2-10GigE-0-3-0-2.l-far.21cn-ipp.bt.net (109.159.249.172)  87.378 ms
11  166-49-168-114.eu.bt.net (166.49.168.114)  88.057 ms  88.012 ms *
12  core1-te0-5-0-4.ilford.ukcore.bt.net (194.74.77.173)  91.078 ms  89.777 ms www.londonlink.com (194.72.7.41)  77.972 ms
13  core4-te-0-0-0-2.faraday.ukcore.bt.net (213.121.193.57)  81.687 ms * *
14  acc2-10GigE-0-3-0-0.l-far.21cn-ipp.bt.net (109.159.249.168)  81.660 ms * acc2-te0-0-0-1.l-far.21cn-ipp.bt.net (109.159.249.190)  77.069 ms
15  * * *
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
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22  * * *
23  * * *
24  * * *
25  * * *
26  * * *
27  * * *
28  * * *
29  * * *
30  * * *

edited
F9 member since 4 Sep 1999
F9 ADSL customer since 27 Aug 2004
DLM manages your line the same way DRM manages your rights.
Look at all the pretty graphs! (now with uptime logging!)
Community Veteran
Posts: 5,109
Thanks: 465
Fixes: 17
Registered: 10-06-2010

Re: Plusnet blocking udp to port 80

We need to fix the traceroute invocation. It should be:
traceroute -U -p 80

Otherwise traceroute is incrementing the port number with each probe it makes.
Community Veteran
Posts: 1,136
Thanks: 2
Registered: 30-07-2007

Re: Plusnet blocking udp to port 80

Traces edited. That looks conclusive to me...
F9 member since 4 Sep 1999
F9 ADSL customer since 27 Aug 2004
DLM manages your line the same way DRM manages your rights.
Look at all the pretty graphs! (now with uptime logging!)
Community Veteran
Posts: 1,841
Thanks: 103
Fixes: 6
Registered: 21-01-2013

Re: Plusnet blocking udp to port 80

I've forwarded port 80 tcp and udp to my pc and tested with the port forward port checker:
It shows port 80 tcp to be open -- confirms my port forward rule is working.
It shows my port 80 UDP to be "Not Open" -- suggests it's being blocked externally.
Community Gaffer
Community Gaffer
Posts: 13,282
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Registered: 04-04-2007

Re: Plusnet blocking udp to port 80

Quote from: ejs
We need to fix the traceroute invocation. It should be:
traceroute -U -p 80

Otherwise traceroute is incrementing the port number with each probe it makes.

Good point.
Quote from: avatastic
Traces edited. That looks conclusive to me...

It does, I'll see if I can get somebody to take a look...
Edit: ref 87983

Bob Pullen
Plusnet Product Team
If I've been helpful then please give thanks ⤵