Score:0

Ubuntu

accessing remote server by ssh ( but ssh port is filtered)

nnmmss

4/8/23, 9:28 PM

I have a few remote ubuntu servers which I don't have a physical access to them. I want to ssh , all of them are saying that the state is filtered on port 22. I have just their Ip address, by using ssh command, I SSH to them, but it is not possible because their port 22 is filtered. how can I access the servers , or reset the filtered port to open it? or any idea

101

0 + 0

ssh

openssh

nnmmss

4/9/23, 1:26 PM

@user68186: They are not real servers. they are programmable cpu boards, which are installed somewhere and only by shh are accessible. unless we have to uninstall them to have physical access.

nnmmss

4/9/23, 2:23 PM

@user68186: I have their Ip address, so I can make a ssh connection toward them

Bodo

4/9/23, 2:50 PM

Please [edit] your question to add information, don't use comments for this purpose. What exactly means "the state is filtered on port 22". Please describe your network and tell us where port 22 gets filtered. Please copy&paste the command(s) you are using and the exact error message. Can you reach the servers when you are at a different location or connected to a different network?

raj

4/9/23, 2:53 PM

What is exactly filtering the port 22? This is probably some firewall on the way between you and the servers. You need to identify where the firewall is and allow port 22 on it.

Thomas Ward

4/9/23, 4:14 PM

There's a firewall in place SOMEWHERE blocking the port 22 access or controlling what can SSH to them. If they're not on the systems themselves, there's a firewall somewhere in front of them. UNFORTUNATELY, without more details about the setup (AWS, etc.) we can't really help debug anything, and if you don't already have remote access to the console, etc. on these boxes then we can't really do anything without access to the machines.

nnmmss

4/9/23, 4:55 PM

@ThomasWard: we installed the Cpu Board on another network which is not related to the original one. again it says that SSH port is filtered. is it possible that ssh is allowd from specific Ip address or MAC address? so the other Ip address couldn't SSH to the Board?

Thomas Ward

4/9/23, 5:07 PM

@nnmmss as I stated, if it's on 'another network' and the networks aren't interconnected via a firewall, etc. to handle proper NAT with proper permission rules, then it could be IP address filtering or MAC filtering or firewall on the endpoint boards, or any number of a thousand reasons. There's just not enough information here to give you a full answer as to what the problem is or how to fix it.

Score:0

Ubuntu

MoRK

1/11/24, 9:58 PM

Seems like your firewall is blocking it, try the following:

sudo ufw status
sudo ufw allow ssh

verify:

sudo ufw app list

or if you have custom port setup for ssh, anything other than ssh's default port which is 22, replace 57325 with yours:

sudo ufw allow 57325/tcp

you could disable totally disable the firewall which is not secure:

sudo ufw disable

+ 0

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: accessing remote server by ssh ( but ssh port is filtered)

TH: การเข้าถึงเซิร์ฟเวอร์ระยะไกลด้วย ssh (แต่พอร์ต ssh ถูกกรอง)

RO: accesarea serverului la distanță prin ssh (dar portul ssh este filtrat)

RU: доступ к удаленному серверу по ssh (но порт ssh фильтруется)

VI: truy cập máy chủ từ xa bằng ssh (nhưng cổng ssh bị lọc)

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.