Observer

Unable to Port Forward uncommon ports

I've been trying to port forward ports (like 6398, for a custom program I wrote, and 9987, for a voice chat server for friends and myself, but despite opening every port on my router to the server machine and having firewall rules on that machine set for those specific ports, only common ports, like 53, 80 and 443 are accessible for incoming traffic. I spoke with a T3 tech on the phone today, and he couldn't figure out exactly why this wasn't working. My previous thoughts were that Spectrum was blocking ports, but he assured me that it's not something they can do, even at the T3 level. So, he told me to crowdsource the solution and post here. If anyone has had experience with this issue, could you please help out?

Thanks

 

EDIT:

Thought I'd include the hardware I'm using, in case that becomes relevant, and because they aren't Spectrum issue.

Modem: Netgear CM-1000

Router: Netgear Nighthawk X6 - (ALL PORTS FORWARDED)

Server: Windows Server 2012 - (Relevant Ports Forwarded, 80 and 443 accessible from outside, 21, 6398, and 9987 are among those that are not)

9 REPLIES
Sharer

Re: Unable to Port Forward uncommon ports

Just to rule it out, are you testing from inside or outside your network? If from inside, you may be running into the NAT Loopback issue (or hairpinning).
Observer

Re: Unable to Port Forward uncommon ports

I am testing from outside, using portchecktool.com and a Linux VPS running nmap

@RAIST5150

Sharer

Re: Unable to Port Forward uncommon ports

Have you been able to confirm within the router's GUI that the rules are indeed active?

For example, in my Asus router, there is a tab for port forwarding under system logs. That shows me the ports and IP's it is actively forwarding to--whether it is manually set rules or done through UPnP.
Observer

Re: Unable to Port Forward uncommon ports

Yes, the rules are active.

Newcomer

Re: Unable to Port Forward uncommon ports

Have you made any progress on this issue yet?    I am dealing with the same issue, trying to open a port for a tcp listener.  With the listener running and all of the rules set, I check it with the online tools like you mentioned and it always shows closed.

  I am using the,  Sagemcom RAC2V1S...  which happens to be the only one i can find in the provided list of routers that in the manual does not have a section for port forwarding.   I am more confused now knowing that you have the same problem with a completely different router.  Id appreciate any more info you have come across... Thanks.

Observer

Re: Unable to Port Forward uncommon ports

I thought that the problem was with the router/modem combo they provided with me, but after switching, it appears to be something with their service. I unfortunately haven't made any progress. I've tried everything, I got on the line with a lower level support representative, who suggested trying Port Triggering. I think she misunderstood what I was trying to do, but even that didn't work, and I'm really just considering switching to business because from what I've seen, their business support team is far more dedicated to fixing your problems. For a static IP and a guarantee that no ports are blocked, at a price of only $15 more a month than similar residential levels, I might just take it.

Observer

Re: Unable to Port Forward uncommon ports

Aside from that, @S1CAR1US, you can reach me @codegremlin#7674 on Discord if you'd like to follow up. I don't get any email notifications from this, so I only check when I think to.

Contributor

Re: Unable to Port Forward uncommon ports

@GlennT2814

I know for certain that Spectrum doesn't block port 21, as I can access my FTP server from an external connection without issues.

To test your "high" ports, I just pointed a browser at my system trying both the ones you mention, 6398 and 9987.  Both incoming connections were refused by my firewall, which shows they got through my CM and that Spectrum is not blocking any of those ports.  At least not on the part of their network that allocates my IP.

Oct 29 13:48:06 Nethserver kernel: Shorewall:net2fwSmiley Very HappyROP:IN=eno1 OUT= MAC=00:25:90:a6:75:d0:00:01:5c:6d:52:46:08:00 src=66.249.84.11 DST=23.243.yyy.zzz LEN=60 TOS=0x00 PREC=0x00 TTL=107 ID=43234 PROTO=TCP SPT=56583 DPT=6398 WINDOW=60720 RES=0x00 SYN URGP=0 MARK=0x10000

Oct 29 13:48:22 Nethserver kernel: Shorewall:net2fwSmiley Very HappyROP:IN=eno1 OUT= MAC=00:25:90:a6:75:d0:00:01:5c:6d:52:46:08:00 src=66.249.84.18 DST=23.243.yyy.zzz LEN=60 TOS=0x00 PREC=0x00 TTL=107 ID=26769 PROTO=TCP SPT=52500 DPT=9987 WINDOW=60720 RES=0x00 SYN URGP=0 MARK=0x10000

Cheers.

 

 

Proven Sharer

Re: Unable to Port Forward uncommon ports

Also remember that Spectrum's Terms of Residential Service do not allow home internet subscribers to operate a data server with outside network access by anyone else.  External server access by others is OK if you have a business account, so you are moving in the right direction.