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Blocked Ports
ClimbGuy
Newbie

On residential accounts does Verizon Fios block any incoming or outgoing ports?

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1 Solution

Correct answers
Re: Blocked Ports
nathan21
Enthusiast - Level 1

READ HERE / UPDATE / ANSWER TO INVESTIGATION.

Bottom-line-up-front: THERE IS NO AUTOMATIC INBOUND PORT BLOCKING on Verizon's network (unless applied by one's own router,,, or possibly special rule). 

...Ugg,, I wish I could take my previous post down,, not to avoid the embarrasment, but more importantly not to confuse the rest of the world.

I just a had a huge heaping slice of humble pie... So, what was the ultimate problem?!

.. The ports in fact were/are NOT blocked.. there were simply not replying because nothing was LISTENING in order to allow/deny/drop traffic. SO,, because nothing was listening except for port 53 (listening both on my computer and router), there was NO OTHER port listening & responding (either open or closed),, so it appeared from the various tools that I was using that my ports were "Blocked", when in fact there simply was nothing on those ports.... I feel dumb. Smiley Frustrated

In the end, we confirmed (as it was already understood), that there is apparently NO port blocking / filtering going on beyond one's own router (from the ONT upstream).  So, my apologies to the community for the bad assumptions in my previous post. 

View solution in original post

Re: Blocked Ports
jonjones1
Legend
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Re: Blocked Ports
ClimbGuy
Newbie

thanks for the link, the postings there are several years old, is it true that the only port VZ blocks is outbound port 25?

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Re: Blocked Ports
jonjones1
Legend

@ClimbGuy wrote:

thanks for the link, the postings there are several years old, is it true that the only port VZ blocks is outbound port 25?


Alas I don't know. I don't use port forwarding.

When a forum user uses the search field it is possible to actually find the fix to the situation. Sort of like a mini google for fios Smiley Very Happy

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Re: Blocked Ports
CRobGauth
Super User
Super User

Do you have a specific port you are concerned about?

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Re: Blocked Ports
smith6612
Super User
Super User

Correct. Only Port 25 outbound. Everything else is wide open.

Re: Blocked Ports
tashi0
Enthusiast - Level 1

There are so many posts about blocked ports and port forwarding. This is my experience.

At the end of 2017, incoming requests for SMB and FTP just stopped working. At the suggestion of Verizon technical support, a factory reset was performed and they sent a replacement actiotec router. Everything was identically configured to the same settings when everything worked. All was checked on the computer/LAN receiving the incoming requests worked fine. External ping worked fine. External port scan showed the ports closed.

Verizon connected me to Actiontec technical support. After their verifying all settings, still nothing worked.

DMZ did not work either, ports still closed.

I purchased the latest quantum router and configured port forward. Also tried using the DMZ setting. Still, port forwarding did not work nor did a port scan show ports open.

One must conclude that Verizon is doing something to block incoming inquiries on all but a few ports that the router keeps open by default. It is possible that Verizon is doing something locally (Pittsburgh PA), and ¿possibly something in the C.O.?.

If someone has another explaination, please post.

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Re: Blocked Ports
nathan21
Enthusiast - Level 1

I have found that that are apparently blocking all inbound ports (minus 53 / DNS[sometimes]) as well as the commenter above, and this is being blocked by atleast the ONT modem (fiber-to-ethernet) level (beyond my router). This includes ALL port, standard and higher / non-standard. Man Surprised I directly connected without a router to test / see / confirm this.

I tried convincing the tech that it has nothing to do with the router, and that it is an overtly BLOCKed port issue, not a port-forward issue. I explained to him that I am DIRECTLY connected to the ONT (no router in between), and able to clearly test that all ports (minus 53) inbound are overtly BLOCKed (not even filtered / "time-out" non-response).

He send me to the Actiontech (Verizon router maker) department, which wasted another 20 mins, as even he eventually agreed this is not a router (forwarding) issue, this is a blocking issue.

[For the record, I did test using other comuters (same blocking results), however i also test going through a desktop VPN (PIA), which allowed MANY more open ports inboud (80, 443, 53, etc), as I tunneded around the ONT.

So, at about ~1.5 hours, we all realized that something at the ISP-access level was overtly blocking ALL ports, and they are going to send a tech out here tomorrow. 

(I hope this is not the new norm post Net-neutrality as this is a recent problem to me, although I would assume it should be unrelated)

Will update with findings after thier work....

Re: Blocked Ports
smith6612
Super User
Super User

One thing to verify is whether the computer's IP Address matches what is seen from a site such as http://whatismyip.com/ and https://whatismyip.com/ (HTTP vs. HTTPS can make a difference if there is CG-NAT or proxying in the mix).

Keep in mind that ports will show as closed/stealth even if there is no firewall present, if there is not an application listening for traffic sent to those ports.

Re: Blocked Ports
nathan21
Enthusiast - Level 1

READ HERE / UPDATE / ANSWER TO INVESTIGATION.

Bottom-line-up-front: THERE IS NO AUTOMATIC INBOUND PORT BLOCKING on Verizon's network (unless applied by one's own router,,, or possibly special rule). 

...Ugg,, I wish I could take my previous post down,, not to avoid the embarrasment, but more importantly not to confuse the rest of the world.

I just a had a huge heaping slice of humble pie... So, what was the ultimate problem?!

.. The ports in fact were/are NOT blocked.. there were simply not replying because nothing was LISTENING in order to allow/deny/drop traffic. SO,, because nothing was listening except for port 53 (listening both on my computer and router), there was NO OTHER port listening & responding (either open or closed),, so it appeared from the various tools that I was using that my ports were "Blocked", when in fact there simply was nothing on those ports.... I feel dumb. Smiley Frustrated

In the end, we confirmed (as it was already understood), that there is apparently NO port blocking / filtering going on beyond one's own router (from the ONT upstream).  So, my apologies to the community for the bad assumptions in my previous post.