I want to allow 100 incoming connections to my linux server running smtp. I know that tcpserver -c will set the limit of allowed incoming connections, but how can I tell what the currently set limit is?
View 4 RepliesI have a bunch of Ubuntu boxes on one subnet, 192.168.1.0. I have a Windows 7 box on another subnet, 192.168.2.0. I am able to ping and SSH to all servers on the .1 subnet except for one server, which I will call PITA. I will attempt to SSH to PITA, and it won't respond, nor does it respond to pings. I will the SSH to PITA from another of the test servers, successfully connect, and then when I SSH from my Windows 7 machine I can connect successfully. If I first connect via console to PITA and send some pings out (to anywhere, like 4.2.2.2), I can also connect from my Windows 7 machine. I've never seen anything like this.
One of the weird things is that I used PITA to create an image that I then used to create many of the other test servers, and they work fine, so I'm not sure what the problem is. I've checked /var/log/messages and syslog and there's nothing in them that indicates a problem. I've rebooted this server, restarted SSH, changed the IP in case it was conflicting with something else, forced an ARP update in case it was cached (since I had bonded the interfaces), cleared the ARP cache on my own machine, verified Network Manager is not installed...and I still have this issue.
Here are some network-related config:
/etc/network/interfaces
Quote:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
[code]....
Im not able to find good response on this from google, urgent help required.
While im looking at my smtp server log at /var/log/maillog, im having these two errors for which im unable to find the reason.
1)Could not open inline file /etc/MailScanner/reports/en/inline.sig.txt, No such file or directory
2)did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA
Its been really bugging me that whenever I scan my connection with wireshark I see this one person sending me a SYN packet every minute on port 445. I know this is the dangerous port that the Conficker worm travels along. So far my computer seems to be immune and I know, at least on the Linux side that I can just add a rule to my ip tables to block that port indefinitely. I want to know what the next step is.
00 0c 41 b2 e4 1d 00 11 09 b2 2f 0e 08 00 45 00
00 30 91 84 40 00 80 06 d1 c7 46 4f 86 29 XX XX
XX XX 10 43 01 bd 9e 23 d6 27 00 00 00 00 70 02
ff ff 65 58 00 00 02 04 05 b4 01 01 04 02
This is one of the packet captures I am getting. After sending me this and getting no reply, all of a sudden he goes up an ip. Basically this would be the pseudocode for what it looks like hes doing on my end.
while(1){
for(int i = 1; i != 255; i++){
send_connection_attempt("XX.XX.XX." + i);
}
}
To me this looks like this guy has hijacked a computer and is using it to run a script over. He is still scanning my network as I said earlier, what should I do? Should I contact my ISP? or just nail down the hatches and make sure nothing is exposed on my network?
I'm looking for a smtp solution that will split all incoming emails and send them to two different servers.
On mail server 1 I have test@example.com
Om mail server 2 (different location than mail server 1) I also have test@example.com
MX-record for example.com should point to mail server 3. Of course there will be a mail server 4 that will do the same as mail server 3. Mail server 3 will receive all incoming mails and forward them to both mail server 1 and 2. This will be a simple and cheap but bullet proof redundancy solution. I'm interested in this solution, have already looked into clusters, backup mx, imap-sync and a ton more of solutions but this is the solution we want. ny one who can point me in the right direction? I've been searching for weeks, the solution exist but I can't find out how to set it up. Not all mail should be forwarded this way, only one example.com, not example2.com or example3.com.
I need some suggestions on software. I would like to offer remote desktop support to some of our clients, but some of them are using ISP's that block incoming connections so, VNC is out of the question. I was wondering if there is something similar to logmein for ubuntu?
View 1 Replies View Relatedincoming connections are not being reported to my /var/log/secure. I can't see if people are trying to connect. I can't troubleshoot because I can't do anything.
View 5 Replies View RelatedI'm trying to get VNC working but I'm getting this error message:
Quote:
ssh: connect to host my_ip_address port 22: Connection refused
When typing:
Quote:
ssh -f -L 5900:localhost:5900 user@my_ip_address x11vnc -safer -localhost -nopw -once -display :0 && sleep 5 && vncviewer localhost:0
I'm trying to follow the instructions here: [URL] but I'm struggling with point 2 & 3:
Quote:
2. If you have previously reconfigured the firewall on your PC, make sure the firewall allows incoming connections on port 22 from anywhere, and on port 5900 from localhost (also known as 127.0.0.1)
3. If your PC is behind a home router, or any other device that uses NAT, configure your router to send connection attempts on port 22 (but not port 5900) to your PC
So my questions are:
1. I installed a fresh version of Ubuntu 11.4, should I be concerned about step 2? If so, how can I allow incoming connections on port 22 from anywhere, and on port 5900 from localhost?
2. Regarding step 3, I'm using NETGEAR model DGN1000 router. Is that something that I should do from the router's setting page or it's some commands that I should pass through SSH?
My question is simple - is there any linux app or applet which is able to show (monitor) incoming and outgoing connections assuming it's a direct internet access? I was using a firewall on a system off Redmont which was able to show every connection, listening ports of services if some were opened etc.
View 1 Replies View RelatedI'm using Linux Mint 8 KDE, which is essentially kubuntu karmic.
Been trying to set up bittorrent (tried several different apps), have followed all the usual steps, forwarded ports on both Guarddog and my router, but still no incoming connections. Then tried disabling the firewall in Guarddog - still no incoming connections. Never had any problems configuring my router before so can only think that there must be something else blocking ports in linux other than iptables.Also had same problem just using ufw and gufw
I am still new to ubuntu and I use firestarter as my firewall tool and I was told that its just ufw in a gui. Well anyways I noticed a connection to 174.129.241.144 using https and python, I didn't have any scripts running and my browser was closed, I read the man files for ufw and it said to do something like deny from 174.129.0.0/12 and I want to block all incoming and outgoing connections to this IP range and I was wondering how to do that, I heard of iptables that it would be able to do this but I dont know anything about it. What I should learn so I can handle these kinds of situation in the future and how I can block this ip subnet or also what does the /8, /12, and /16 stand for?
View 7 Replies View RelatedI have a domain name registered in asianet.com, they provide email service also, can i use local mail server and registrar's smtp server at same time?
View 5 Replies View RelatedI have a server that I can only access via SSH (it's located far away) and I would like to secure it by blocking all ports except the ones that I need (which are HTTP and SSH). I still want to be able to make outgoing connections to enable software updates and other things.This is my iptables -L -n :
Code:
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
DROP tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpts:1:21
DROP tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpts:23:79
DROP tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpts:81:65535
code....
In my opinion, this should block all incoming packets except the ones on port 80 and 22, but allow responses to outgoing connections. But a wget http://google.com does not work, it can't establish the connection.
Maybe this is not the best style for iptables rules, but I want to be absolutely sure to not accidently lock myself out from SSH, so I chose not to configure a "block-everything rule".
Does this configuration not enable incoming packets from connections initiated from inside?
In order to have greater control over the emails sent out the company I imagined the following scenario.ScenarioDescribing in words what I need.ser sends an email to user@hotmail.com for example, using the smtp of my isp (is the internet).Before the email is sent, the firewall checks if the recipient is blocked transparent, if you are locked out rejects the email.I searched several forums and mailing lists, but did not find scenarios similar to mine.Where found situations in which the mail servers were internally in the company, which is not my case.
View 2 Replies View Relatedis that my isp's smtp service is very poorso i want to configure my own smtp servr for my internal clients only for sending emails not receivingi have static ip on my router with 25 port forward i have configure sendmail on linux its working fine on local network mean its sending email on local domainnow i want to send emails on other external domains with my public ipMean user of mydomain.com should be able to send emails on all internet domains like yahoo.com, hotmail.com etc
View 8 Replies View RelatedI want to allow all IPs to use my SMTP server running postfix. what should i write in mynetworks section?
View 4 Replies View RelatedI was looking for a way to send email to the outside world and installed mutt, and noticed that when my pc starts port :25 smtp is up, so I figured that I could send email to the outside, after a few seconds it shuts down.... what could that be? and do I need to install a full flesh mail server in order to send outbound email?
View 6 Replies View RelatedI have installed a linux server in my office to run 16 machines. Its main use will be a internal mail server but will be also running websites.
I have installed Ubuntu 9.10 server x64 and have got apache running.
I am looking for the simplest more robust solution for smtp, pop3 and imap. I have only ever used qmail before and found it a pain to configure and its getting old so I though I should probably try something new. I have not much experience with running pop3 or imap on linux so would love a suggestion on that.
What is the easiest way to setup an incoming and outgoing mail server on centos? Without using a control panel, such was webmin.
View 2 Replies View RelatedI want to have separate incoming and outgoing mail servers with smtp authentication.
Server1 will act as incoming mail server
Server2 will act as outgoing mail server
How can i authenticate domains users of Server1 from Server2 for smtp authentication.
I am working on linux server with below specifications.Linux EDT 2008 i686 i686 i386 GNU/LinuxWhile checking the status of the server using the command 'opmnctl status' and when server is down the output is not getting redirected to file.I m using the command as,opmnctl status > abc.txt.
View 2 Replies View Relatedhave a problem with my network-manager in ubuntu 10.10.when I dial one of my vpn connections, my other vpn connections be disabled and I can't use them!I tried to restart network-manager and gnome-panel, but it does't seem to solve this problem.
View 1 Replies View Relatedhow do I create a shell script that looks for connections running on a oracle database. e.g connection name is CONNECT and database name is DBTEST. I want to know what processes with the name CONNECT are running in database called DBTEST. Am creating the script on the server side. I know about the ps -ef | grep command but how to point to a particular database I don't know.
View 4 Replies View RelatedI have installed talk on centos, turned it on by editing xinetd.d/talk and setting disable=no.I have restarted xinetd (service xinetd restart) and verified that talk is configured to start (chkconfig --status-all).what am i missing? shouldn't either port 517 or 518 respond to telnet? what else can i do to get talk running?
View 2 Replies View RelatedI use php to send newsletter via sendmail.outgoing emails work as needed.I defined a .forward file to get responses in my regular email account.If I use mailx to send emails from root account to my own account, it gets forwarded as needed.If I try to send from outside the box to news@domain.com the email is not received in the box and the sender does not receive an error message.
I am sure I missed something.How do I enable incoming emails?
i'm attemping to re-route incoming traffic of https to one of my servers. (a windows xp with subversion on it)
problem is if i do that ALL https traffic from other pc's is stopped. meaning i can't get any reply from any url with https;
i have a mail server that uses Postfix as a mail server, it runs ok, but i need to add some features to a specific users only.what i need to add is Auto-reply message for some users only.
View 5 Replies View RelatedHow could we bcc all outgoing / incoming email through my Sendmail (8.14) Server?
I tried this /etc/procmailrc
:0c
! backupmail@domain.com
But this get looped and backupmail received multiple emails of each for domain.com while sending locally from one user to another user.
How do i set my ubuntu server to use port 4055 for incoming telnets>
View 1 Replies View RelatedI installed a new server running CentOS 5.2. I have iptables and SELinux off. The new server will not accept incoming mail. It will send out fine.Our mail server redirects mail for it.help to it.[url]...- [url]....is this server. Any messages sent to this address get stuck in a deferred queue. The error message on each one (from the mail server admin console) is "connection to[url]... [10.9.10.202] - connection refused". I can ping [url].... from the mail server.
This seems like a firewall issue, but it is off. Is there some configuration file I need to change to allow incoming mail? Or is there some test I can run on the new server to further troubleshoot what is going on