Networking :: Number Of TCP Concessions With Telnet?
Dec 11, 2010I have a doubt. If i write for instance the command "telnet myserver.mysite" and I manage to connect to the server, how many TCP connections are established?
View 2 RepliesI have a doubt. If i write for instance the command "telnet myserver.mysite" and I manage to connect to the server, how many TCP connections are established?
View 2 RepliesIf I only want to let a user be able to login via telnet a max number of times equal to 2 how would I go about doing this?I have found this little tid bit:per_source = 2but that only allows 2 connections from the same source (i.e. network) and that would not work. For some reason our telnet sessions are not dying off after a user has shutdown their PC and then the next time they login it adds another telnet session.
1. user1 31300 /dev/pts/409
2. user1 27539 /dev/pts/539
3. user1 18042 /dev/pts/316
[code]....
I am trying to find the difference between the above two services. Both are under xinetd and can someone please explain the difference between them (is one more secure than the other one?)
View 1 Replies View RelatedI have some APC UPS devices that I'm trying to log in to. They are currently configured to use telnet -- as a safety precaution, they can only be accessed from our 'bounce' machine. So because I want to do this from a script, I'm doing it like this ssh decoherence@bouncemachine telnet stupidAPCdevice
This works fine on all the other devices I'm trying this on (Cisco gear, mostly) but the APC won't take any input. I get the login prompt but when I type in my username, ssh echoes it but the APC doesn't appear to ever receive it. It just hangs there at the username prompt. I'm guessing that its telnet implementation is a bit weird (seriously, all the management stuff on APC gear really sucks but anyway
Anyway, I'm just wondering if there are any simple flags I can pass to telnet to make it cooperate. The man page talks about a 'mode' command that lets you fiddle with LINEMODE which sounds like it might be promising but I don't know how to set that in the command line as opposed to interactively.
how to use telnet command
View 3 Replies View Relatedinstall telnet in fedora 14 then how to configure telnet?
View 13 Replies View RelatedI have Ubuntu 9.10 hooked up to my router through a wired NIC, and a couple of windows machines that are connected to the router through wireless cards.I want to telnet or ssh into the ubuntu box using putty on one of the windows machines. I have attempted to do this using the ubuntu ip address and the name of the box, and neither approaches have worked.
View 1 Replies View RelatedI would like to write a small configuration utility that will act as a daemon on the telnet port and SSH port that will only allow access to, and modification of, specific information in a structure imposed by the utility. How do I set this utility up so that when a user opens a telnet connection (or ssh) to the device, they are actually connected to the utility?
View 3 Replies View Relatedmy company there is 1 RHEL5 server and around 50 systems connected to it( running windows ). I want to know who is pinging or telneting to the server how can I find this information on the server OR where should I look for this information in the linux.
if I want to explore on this topic (i.e. who is trying to connect to server, from where user accessing server, whats his/her ip, whats his/her os etc. ) where should I look for it on the net ??
I am trying to use telnet from linux to connect to the port specified by me and trying to handle control C. But once Ctrl C is pressed the output on the client side stops showing. The server sends data but client doesnt print the same.
View 2 Replies View Relatedi want to open specific port using iptables i.e 3159 Whenever i tried to telnet it generates the following error
Code:
# telnet 172.16.4.100 3195
Trying 172.16.4.100...
telnet: connect to address 172.16.4.100: No route to host
telnet: Unable to connect to remote host: No route to host
but when I stopped iptables
Code:
# service iptables stop
Its working fine
i added the ports in iptables i.e.
Code:
#iptables -A INPUT -p tcp --dport 3195 -j ACCEPT
for safe side I also added telnet port
Code:
# iptables -A INPUT -p tcp --dport 23 -j ACCEPT
but result was same.... In short telnet works without iptables but with iptables it generates the error mentioned above
Hey even I'm not able to telnet to IPv6 address on port 23
View 2 Replies View RelatedWhen I execute a command (ping or telnet or ssh) on ip 192.168.0.20 it is ok.
If I execute the same command on
ip 192.168.0.020, it looks for
ip 192.168.0.18 instead of
ip 192.168.0.20
And it's the same for others ip if I put a 0 ahead last byte.
When I ping a destination IP address, it responds. However, when I try to telnet or ftp or sftp to the same IP address, it does not connect.
I do not know the physical location of the machine.
I'm running Telnet Server, VFTP, and VNC on a Fedora 14 box. The box's internal IP is 192.168.1.222 This machine is configured to live in the DMZ, The firewall is up on both the router and this box. I can remote in from home using our external IP. I can FTP. I can Telnet. All using our external IP. When i'm in the office, i can remote in using our external IP. I can FTP. I can Telnet. Again, all with the external IP. If i attempt to telnet 192.168.1.222 i get a connection refused. i can ping the 192.168 address
nmap tells me that all 1000 ports on 192.168.1.222 are closed
nmap tells me that my expected ports are open on the external IP.
.... This is a relatively new conundrum as it "used to work", and only appears not to since our last reboot (power outage). I know i have to be missing something simple here, but i differ to the experts.
I have a sendmail daemon running on Linux, I can telnet @ port 25 from local shell, however if I telnet from a remote system @ port 25, it doesn't work. There is no firewall in between.
View 3 Replies View RelatedWrong prefix, its Ubuntu not Lubuntu. Three devices:
Laptop 1:
---Can ssh to any device.
---Accepts any internal ssh.
Desktop 1:
---Can ssh to any device.
---Accepts any internal ssh.
Desktop 2:
---Can ssh to any device.
---Can ssh to itself through localhost or 192.168.1.130.
---Any ssh(and telnet) aimed at this device times out.
All three devices recently had openssh-server installed yet only one seems deviant. I've been trying to ssh into desktop 2 to no avail, yes the machine is reachable, yes sshd is running, yes ufw is disabled, and no there is no external firewall that I know of. Anything else I can try? The router for the LAN being dd-wrt.
I implemented postfix as mail gateway but i need to block the ability to send
mails via telnet
How can i achive this?
I have a customer who is complaining that they can connect to prt y on IP x with telnet. They are seeing the following:
telnet x.x.x.x y
Trying x.x.x.x...
Connected to x.x.x.x.
Escape character is '^]'.
after some time the connection of course times out. Connection closed by foreign host. There is no telnet service running on this port so they cannot do anything, but they are complaining tht the fact that telnet "connects" is a security risk. I am having difficulty explaining why they are able to connect with telnet. I know it has to do with the socket layer API in Linux but I am having difficulty explaining this sufficiently. I also can't just say "this is the way linux works" to them. I am looking through "UNIX Network Programming" by W.
I have a question about telnet.Is there any way to configure a telnet server without disable firewall.I am using redhat 5.2 and fedora 12.I have lack of knowledge about firewall.
View 1 Replies View RelatedI am facing an error when I run the following command telnet localhost 7777
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
I can telnet mx1.hotmail.com 25 from all other machines, apart from my newly installed ubuntu 9.10 laptop. I just installed exim4 and mailx and set in /etc/exim4/update-exim4.conf.conf: dc_eximconfig_configtype='internet' But I can't send mail cause telnet mx1.hotmail.com 25 doesn't work. I can ping mx1.hotmail.com just fine.
View 2 Replies View RelatedI have recently upgraded to a VPS for the purpose of web hosting a group of sites related to my business.The reason for the upgrade was because we wish to run a shopping cart software which required greater memory for PHP and the VPS was the most economic solution. So, I have very basic linux knowledge but I am the definition of a newbie when it comes to going further than just scratching the surface of server configuration! I have successfully hosted our main site for a number of weeks but recently the postfix service stopped sending mail. I have Plesk Control Panel installed and postfix continually shows as not started even though in SSH the service status is definitely running - I have gone through the troubleshooting checklist here (http://www.postfix-book.com/debugging.html#d0e6) but can't get any further than section 2.1 as when running the host command (#host relay-test.mail-abuse.org), I get # -bash: host:command not found. I've gone further in the document but not found any issues...
When postfix was working properly (i.e. sending emails!), the plesk CP showed the service as started and all emails from the website were sending as normal. The mailq command is showing the messages stuck in the mailq and the maillog shows the following:- http://pastebin.centos.org/36446 - these are the latest few pages.To check the configuration and basic elements I have flushed the mailq (which shows a stack of messages waiting) and I have also spent a long time (2 weeks) reading up on the parameters that should be in main.cf and master.cf.I have found that when I 'telnet localhost 25' I get the following response...[root@s15397216]# telnet localhost 25Trying 127.0.0.1...Connected to localhost.Escape character is '^]'.
I'm working on setting up access for our developer via Telnet, we are on a local network behind a physical firewall. I set up the standard Telnet service for Fedora15 and from localhost I can login via any user and root.... However I cannot login from another terminal on the LAN, even though I can ping and FTP to the fedora15 box. I added the firewall rules for telnet, that did not work, so I disabled the firewall, still cannot get a connection via port 25. I feel either port 25 is closed in another manor or the telnet is restricted to the localhost.
Also I cannot login to root to configure the Firewall Desktop GUI, only standard users, is this an issue? I also cannot login to the console as root even though I use the correct password.I can only su to root and sometimes it is a PITA. There must be some settings to clear these issues up...
I can telnet (while on the actual machine) using
Quote:
telnet localhost 25
When I try and use the local machine's ip
Quote:
telnet 192.168.100.9 25
I get
Quote:
Trying 192.168.100.9...
telnet: Unable to connect to remote host: Connection refused
[Code].....
This last one is strange as I the IP looks odd.
What I am doing wrong, and how do I fix it. After much surfing many mosts say that telnet is not used anymore but I want to use it to test my smtp server.
So we have DNS round robin set up for 4 servers. If we ping dns name (basically an alias) server_connect it resolves with different IP address in round robin format. I.E. x.x.x.1 x.x.x.2 for the 4 different server IP addresses. When we do nslookup server_connect it will come back first time as server1_connect server2_connect through server4_connect so the server is able to resolve through ping and nslookup resolving the initial dns name (alias) to the dns name associated in the round robin. Problem is when we try to connect with http or telnet it comes back host unrecognized. I can put one of the 4 round robin servers in /etc/hosts and it connects fine so I'm thinking that either one of three things.
1) ttl
2) It does double connection first to identify itself to the round robin server and then handshake but second time it hits for the handshake the IP and dns name is different than what it expected so it fails.
3) Since we are trying to telnet to dns alias and it is returning different dns name it fails.
2 and 3 seem most promising but now I'm at a stand still.Anyone else come across this issue and if so how did you resolve.
I am running CentOS 5.1 on VMware on Win 7 On CentOS I added Bridged network adapter and the server is connected to internet without any problems, but when I telnet any server on port 25 I get connection timeout.
Code:
telnet f.mx.mail.yahoo.com 25
Trying 98.137.54.237...
telnet: connect to address 98.137.54.237: Connection timed out
telnet: Unable to connect to remote host: Connection timed out
I stopped all servers, iptables and sendmail on the linux server and the firewalls on the win 7 but still getting the same error! I added new network adapter ( host-only ) and tried to telnet the win machine from vmware Linux but I got connection refused
Code:
telnet 192.168.71.1 25
Trying 192.168.71.1...
telnet: connect to address 192.168.71.1: Connection refused
telnet: Unable to connect to remote host: Connection refused
[code]....
When i am trying to telnet to a machine connected in our LAN ..
telnet: Unable to connect to remote host: Connection refused
What's the reason for this? how do i establish a connection? I am using ubuntu 10.04.
I have opened/added the ports 1812 and 1813 (both tcp & udp) for radius server in the firewall.
when i use the command : telnet localhost 1812 , the connection says "refused", i get the following messages code...
I was having no problems (that I knew of) browsing the web since installing Ubuntu 10.10 a week or so ago. I was previously trialling Win7 as my customers will likely be using that in the future. Then I wanted to go to internode.on.net. Got the following: Quote: Firefox can't establish a connection to the server at internode.on.net. or Quote: Oops! Google Chrome could not connect to internode.on.net
As it was just after Christmas I thought it must be down, for upgrades or maintenance etc. I later tried to go to Freebsd.org; same error. I've been having a small number of other websites give the same error. I thought nothing of this until I tried it on my wife's macpro. I could log onto all the websites I wanted to and none gave any indication of having been down. Both boxes are on the same adsl connection. I still can't access internode or freebsd on 10.10 yet have been able to access every website on OSX. Now, I was only looking at them for info but am worried I won't be able to access something important. (so far everything I 'need' is working)
ping just drops out. edit: weirdest thing! I just retried and now can not emulate the problem for internode. freebsd still won't show. that is less than five minutes between problems and resolution! I hadn't even posted! But I still would like to have an idea of what is going on. Here is the ping error for freebsd: Quote:
[Code]...