So I have two ssh servers I connect to regularly that do not use the standard port 22, so I use the "-p" flag to connect to them. This works flawlessly EVERYWHERE except on my girlfriend's work network. When I am on that network (same laptop), I can ssh into servers which use port 22, but not the other servers on this alternate port.Is there any way OTHER than ssh'ing into a machine I can access and then ssh'ing again from there to my destination (which, by the way, does work)? I want to make a direct connection for speed and security reasons.
VERY new to linux, erm but I have an issue that needs solving!I recently moved to university, where their network blocks sftp port 22, this means that I cannot connect to my FTP server which is running a version of linux.Now I've got this ftp server connected to a seedbox and it was created using the following walk through..Code:I have written this guide for a friend, but I though it would be useful for others as well.
There are several guides floating around, but I found that most always cock up in some way. This one is tried and tested to work on Debian Etch (on an OVH rps, but should apply to most servers).If there is a new stable release of rtorrent/libtorrent then I will update this guide to show you how to update it (without reinstalling the whole server).
At the bottom there are also instructions to install ftp access & some network monitoring software.Basically, I would really like someone to be able to construct the commands on how to change the listen port for sftp connection on linux or add another port to the list that Linux would use so that I could put in through putty.
I have a mail server on which I would like to block port 25 on my eth0 for everyone except our external spam filter. the problem is that I want our users to be able to connect via port 10025 which is forwarded to port 25, which then is blocked...
So I set up an Ubuntu 10.04 server with apache2 installed, but for some reason I can't get to it from my browser. the iptables have all changed directories in 10.04 so I can't find the iptables. Apparmor wasn't the problem. The network hard ware is not the problem.There is something inside of 10.04 that is blocking port 80. I can ping it all day using the ip address but when I ping it useing http://ipaddress it can't find the host
I can't seem to establish a conncction to my site (that I'm hosting in the same computer as the gFTP client- running Lucid Lynx desktop as a server). My site is 'out there', with a domain etc. and also I work on it with localhost. I wanted to use ftp as Joomla has a 'ftp layer' for files permissions etc. But it keeps saying that I can't connect, or the connection 'was reset by a peer' whatever that means. For 'hostname' I use site.com (site is my site's name) and even tried the whole thing like http://www.site.com (I clicke on 'connect to remote, and enter that in the url). or just put it where 'host' goes (when I'm not using localhost) For user name and pass, I just enter what I usually put to access the administrator's back panel in joomla, but maybe I am supposed to use what I use to log on to ubuntu when I start my computer? note sure. Anyway I used a telnet command in the terminal and found that port 21 was blocked. MY isp says they don't block any ports so I don't know. I was able to do this last year so I don't know what is so hard about this lol In the router, I have 'ftp 21 to 21 and ip address 192.168.1.100 (ip is the same for http which is working as I have my site up) now it seems to be open as I used a command at the terminal (found from google). It's open but my ftp still can't connect to my server either localhost or to my site. there is no firewall blocking it and I think my router is set right.
Last night I installed all the updates that were available for CentOS. Today, I discovered that all connections to port 25 (Sendmail) are being blocked except connections coming from localhost.
I tried disabling the firewall to see if anything would change but it is still blocked.
If it is not the firewall doing the blocking, what else might it be?
Recently I discovered that we were accidentally running a POP server (port 110), when we only should have been running the encrypted version thereof (port 995). This wouldn't have been a problem if the port was blocked in the first place.Isn't the default iptables setup on CentOS to block unspecified ports? Specifically, this line from /etc/sysconfig/iptables
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
Right? Well, this doesn't seem to be working for me. I added some rules to allow additional ports and commented out a couple (crucially port 110), but for some reason, port 110 is open.Here is /etc/sysconfig/iptables and the output of iptables -L below that:
# cat /etc/sysconfig/iptables # Firewall configuration written by system-config-securitylevel # Manual customization of this file is not recommended. *filter :INPUT ACCEPT [0:0]
[code]....
Why isn't "-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited" doing what I think it should be doing?
I have tried setting apache up on port 8000, because my ISP blocks port 80.
When I try to listen on just port 8000, I can never connect, internally or externally. When I try to listen on both 8000 and 80, my internal computers will drop the 8000 from the url and connect on 80, and external computers try to do the same thing, but can't get through on port 80.
I know my router is set up correctly, I have 80, 8000, and 8888 all being forwarded, I have confirmed with [URL] that 80 is blocked, but 8000 and 8888 are open. I am able to connect to gnump3d through port 8888 internally and externally, but not apache2 on port 8000.
netstat -tnap confirms that apache is running and listening on ports 80 and 8000 to all users.
I have a vps server running certain services which can be accessed via a web browser (e.g webmin control panel), but I have recently been unable to access these services from my home machine using Firefox 5.0, running ubuntu 11.04.
Example:
I can access the server on port 80 fine, eg: [URL]
However I cannot access my webmin control panel on: [URL]
The pages takes ages to load and then times out. Same with transmission-daemon on: [URL]
Everything is set up fine on my server, the ports are open in firewall etc. and I can access these pages fine from my work computer.
This has only started happening in the last day or two and had been working fine up till then. I have not messed around at all with the firewall on my home machine. I have tried other browsers besides Firefox with same result.
I have a fresh installation of CentOS 5 I'm using for a server, and I'm having issues with port configuration. I have iptables running, and it started with no /etc/sysconfig/iptables file. I added a few basic rules (port 53, port 10000 for webmin), saved the file, and restarted the service. I tried connecting to webmin, scanned ports, and traffic was blocked. I set iptables to allow all traffic and restarted the service, and it still showed basically every port as being blocked. It seems port 80 and port 22 work for some reason, even when I tell iptables to block all ports.
I'm not sure what's going on here. Iptables is reading the /etc/sysconfig/iptables file, and if I use lynx localhost:someport it responds as it should according to the file. However, if I try connecting by IP, it's like there's some other firewall or something running that does whatever it's configured to do.....
Strange issue here when trying to verify firewall on Server 8.04. No ftp service running at all on server, but both nmap and netcat report port 21 as being open, even though it isn't.I am 100% sure that port 21 is not actually accessible and iptables rules are fine. Trying to connect to the port fails, yet nmap and netcat seem to report a "false positive"?Have also checked on a number of other servers I'm running, and this "false positive" seems to apply to all of them.
I installed Ubuntu 9.10 and tomcat 6 java servlet container. I am trying to run the tomcat server on port 80, so I edited tomcat's configuration file (server.xml) and changed the default port from "8080" to "80". I launched tomcat server, went to my browser and entered:[url], but it says can not find server/location. Then I edit the server.xml and revert back to port "8080" and then enter: [url] and everything works fine. So my guess is some other service is taking up port 80, but I would think not, since I just installed Ubuntu and made sure apache isn't installed or running.
So I went to "System" --> "Administration", then choose "Network Tools". I then executed Netstat and did not see anything taking up port 80, but I do see port 8080 taken (assuming it is the tomcat server). Then I also did a Port Scan and entered my IP number. Again, I don't see port 80 taken, but do see 8080 being used.
I had a winxp laptop computer behind home wireless and was running tomcat 6 server fine with it, but it over-heated and died recently. So I got a used laptop and just installed Ubuntu 9.10. I have not changed my wireless router settings. It is the same as before. So I have ruled out my home's hardware/network equipment.
So here now I sit, wondering what is up?
For security reasons, is port 80 initially blocked by Ubuntu for some reason? Is there something I have to do beforehand to free up port 80?
I have a Centos 5.5 system with 2* 250 gig sata physical drives, sda and sdb. Each drive has a linux raid boot partition and a Linux raid LVM partition. Both pairs of partitions are set up with raid 1 mirroring. I want to add more data capacity - and I propose to add a second pair of physical drives - this time 1.5 terabyte drives presumably sdc and sdd. I assume I can just plug in the new hardware - reboot the system and set up the new partitions, raid arrays and LVMs on the live system. My first question:
1) Is there any danger - that adding these drives to arbitrary sata ports on the motherboard will cause the re-enumeration of the "sdx" series in such a way that the system will get confused about where to find the existing raid components and/or the boot or root file-systems? If anyone can point me to a tutorial on how the enumeration of the "sdx" sequence works and how the system finds the raid arrays and root file-system at boot time
2) I intend to use the majority of the new raid array as an LVM "Data Volume" to isolate "data" from "system" files for backup and maintenance purposes. Is there any merit in creating "alternate" boot partitions and "alternate" root file-systems on the new drives so that the system can be backed up there periodically? The intent here is to boot from the newer partition in the event of a corruption or other failure of the current boot or root file-system. If this is a good idea - how would the system know where to find the root file-system if the original one gets corrupted. i.e. At boot time - how does the system know what root file-system to use and where to find it?
3) If I create new LVM /raid partitions on the new drives - should the new LVM be part of the same "volgroup" - or would it be better to make it a separate "volgroup"? What are the issues to consider in making that decision?
I want to do a simple port redirect, i.e. whatever comes trough whatever interface on port AAAA will get redirected to port BBBBI thought that iptables -t nat -I PREROUTING --source 0/0 --destination 0/0 -p tcp --dport AAAA -j REDIRECT --to-ports BBBBhowever it doesn't work, e.g. nc -v -w2 -z localhost AAAA gives:
nc: connect to localhost port AAAA (tcp) failed: Connection refused while nc -v -w2 -z localhost BBBB
I have a mail server i need it to send message via port 587 not port 25, i make some changes to my postfix server which i use and it is already successed making a telnet to 587 port like it :
sudo ssh -L 750:192.168.123.103:873 username@192.168.123.103It does exactly what it's supposed to do, but how do i edit / remove this rule?Is there some config file where i can alter the forwarding? How does it get stored?Im using Ubuntu 10.10Server Edition (allthough i recon it would be pretty much the same across all versions
I'm not that great with mailservers, and just been thrown a curveball with a MS Exchange environment for which there is apparently no solution... yeah, right. But is there a workaround?
The problem is that the site mail (SMTP) needs to be sent via port 26 instead of the commonly used 25. Port 25 is mapped to a mailfilter, which apparently causes havoc with some of the mail, and the techs that have been on site trying to coax the Exchange server to co-operate have said that the only way would be to get rid of the filter.
The problem is that there are number of apps that are unable to have the outgoing port changed and so keep sending mail out on port 25.
I look after the Unix/Linux side of things at work, and I was wondering if there was an easy way to set up a Ubuntu box to receive mail on port 25 and just forward it to the MS box on port 26? So, in other words (and I hope this makes sense): monitor port 25, and forward whatever comes in on port 25 to the server on port 26. Simple portforwarding, or is it? What steps do I need to take?
everything works fine. I can log in, and local port forwarding is done. Otherwise when I use the command:
ssh user@ssh_server -R 5500:localhost:5500 -p 22
I get an error "remote port forwarding failed for listen port 5500". However when I try remote port forwarding in WinXP by use of putty there is no problem...
I can't seem to remotely SSH or VNC into my machine. If I'm on the LAN and try accessing via LAN IP, it works fine. If i go in through a remote address (my dyndns) or even my home IP, I can't connect (yes, all of the ports are forwarded, I've triple checked this multiple times). Interestingly enough, port 80 works just fine. It would seem as though some sort of firewall is blocking me. I've done this plenty of times before with various machines, and this has me quite perplexed.
I dont know how, but somehow all the ports on my comp appear to be blocked except for 24, for ssh and 5900 unknown. I can connect to the network, but as far as I can tell, I'm powerless to do anything. No webpages load, I'm typing this on my phone.
I tried to install the packages for atmel at76 in order to get my usb wifi dongle work, the Kpackagemanager told me that "some modifcation are necessary to acomplish the task" on followings packages:
linux-generic linux image-generic linux firmware.
When selecting okay the following error message appear :
"The following packages block the update: linux-generic linux-image-generic linux-firmware"
I am trying to use Bittornado with iptables via Firestarter. Previously, I had no problems, but now I have started using Firestarter, traffic is blocked. AIUI, after selecting the .torrent file, the client (me) connects to the tracker. In Firestarter, I see that my IP is trying to connect to various ports, all of which are blocked.I assumed the problem was that because Firestarter has a restrictive outbound traffic policy, that I needed to add Bittornado to it. So in Bittornado, I selected the acceptable ports as 10000-10010 (randomized), and then in Firestarter for the outbound policy I allowed those same ports.The inbound traffic policy has no rules. All traffic is permitted and I have a direct connection to the Internet (no NAT). I do not understand why, if I have selected the permissible outbound ports in Firestarter, and also selected those same ports in Bittornado, why connections between my IP and the tracker are blocked?
I'm trying to connect to the www.freeopenvpn.com vpn service from my ubuntu 10.04 netbook edition. Installed the parts based on the instruction of the website, then the connection successful (lock icon on the connection area) but.....
the traffic does not go through, ping rejects with some "buffer error", network monitor does not show any data flow on the lan card. after the connection. Was trying it from commandline, and from gui as well. Same result. Can't even navigate to the service start page.
I do not have firewall, using the linksys built in firewall in my router. The same (dual boot) machine and router let the same vpn work under win XP, so the hardware is fine.
I suspect that it is a routing problem. (using dhcp from the modem-router)
Found that the vpn module installed the virtual tun0 interface and set up the routing table automatically.
I am still trying to run my Write It Now4 under Wine. The first time I couldn't figure out how to do it and then I changed the permissions to give myself Execute permission.This allowed me to install it under wine.When I went to open it, I was given the message again that it was blocked by Ubuntu. How do I unblock it. I have the rights to use this program but the people upstairs seem to know better. this is why I am trying to leave Windows. I don't like my computer telling me that I cannot do something I know I am allowed to do because someone somewhere decided it was not good for me.
I've setup the Uncomplicated Firewall (UFW) on Ubuntu 10.04 LTS and blocked an IP address. UFW status shows that the firewall is active and the IP in question is denied. The issue is that I'm seeing the blocked IP address in my Apache logs.
