General :: Cannot Receive Inbound Connections Or ICMP?
Jul 5, 2011
I'm facing a strange problem. I have a Debian squeeze machine connected to Internet through a 3G USB modem. The machine connects as expected, and I can resolve domain names and establish HTTP and SSH connections.The problem is when I try to communicate to that machine from another PC connected to Internet. The machine doesn't respond to PING and I can't connect to the SSHD installed in it. If I connect the machine to the local network, it works right.
route:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default * 0.0.0.0 U 0 0 0 ppp0[code]...........
View 1 Replies
ADVERTISEMENT
Jul 9, 2009
I have a C program which does.
1. Creates a UDP socket
2. Send the UDP Request packet to the TFTP server.
3. If the TFTP server is not listening in the 69 port, the remote machine send an ICMP ("Port Unreachable") message.
Is there a way to receive a notification from the Linux kernel on receipt of an ICMP packet to the created UDP socket.
View 1 Replies
View Related
Apr 6, 2011
I am running Ubuntu 10.10 I have an question about the firewall Firestarter, when checking the firewall it told me there are 9 serious incoming connections what must I do with this info. Inbound is normally blocked as standard i have also see that someone with port 1234 and 12345 have trying to attempt mine system but failed all trojan ports are fully blocked.
View 2 Replies
View Related
Apr 7, 2011
I'm trying to adjust the firewall to only inbound syn connections.
To Allow all home subnets access to port 53 both tcp/udp but deny the rest.
View 1 Replies
View Related
May 21, 2011
I am setting up a virtual server. Ubuntu 11.04, "minimal provider image".UFW was disabled by default. I set it to default deny. Allowed HTTP, SSH and other standard stuff, and enabled it. All seems to be OK. Adding one rule to block some annoying security scanners causes ping not to work. I'm not an Iptables expert, but it looks OK to me. I got it from some website, rather than invented it myself, but modified to to fit the ufw config file syntax. What in that rule prevents pings?!? It seems completely unrelated.
View 1 Replies
View Related
Jun 1, 2010
How to check inbound and files transfer from outbound to inbound in my linux server. because in my server from outside to inside transfer is high. so its take huge bandwidth. how to check this and reduse this .
View 2 Replies
View Related
Jul 20, 2010
1. It is definitely my system and not the router. I had been accepting these connections just fine on my Fedora 6 system, but upgraded to FC11 and haven't been able to get these inbound connections working. I still have the drive with the FC6 system and whenever I put the old drive in the system, the connections work fine. So, the hardware, wiring, etc is identical between the FC6 and FC11 systems.
2. The system's firewall is disabled. iptables, and ip6tables are turned off both at startup (e.g., chkconfig iptables off) and using "service iptables stop". (Note--my router also works as a firewall)
3. sshd and httpd are both on and listening on all interfaces. "nmap -P0 -p 22,80 127.0.0.1" shows both ports open, as does 192.168.1.80. But when I use the same command looping through the external IP, the ports are filtered:
Host is up.
PORT STATE SERVICE
22/tcp filtered ssh
80/tcp filtered http
4. hosts.deny is empty.
5. The messages and secure logs do not show anything in response to the nmap scans.
Again, I'd have sworn this was my router, except that it cleanly allows the traffic when I swap the drives in my system.
View 9 Replies
View Related
Aug 12, 2010
How to work GNUGK for H.323 Gatekeeper.
I am having a problem, configuring static call routing on GNUGK
In the section
You can see that the routers Local-router1 and 2 has the same dialling plan.
What happens is the gatekeeper send calls randomly to one router or to the other when one of the matching extension is dialled.
What I am trying to do is to force
Any calls coming from Remote1 to go out only throught Local-router1
Remote1 =========================> Local-router1
And any calls from Remote2 to go out throught Local-router2
Remote2 =========================> Local-router2
View 1 Replies
View Related
Feb 7, 2011
have 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 Related
Sep 23, 2010
How can I disable ICMP messages through the configuration file of /proc/sys/net/ipv4/ICMP_echo_ignore_all Also how the above file can be edited?
View 1 Replies
View Related
Jan 21, 2011
Is it fair to say that connLimit and hashlimit are very similiar on Linux i.e. while hashlimit caters to limits for groups of ports, they both set the connection rate limit per host? How in IPTables, do I configure a policy that limits connections on a port that encapsulates the total sum of all connections from all hosts? i.e. I do not want to allow more than 6000conn/minute for port range that is the sum of all connecting hosts?
View 3 Replies
View Related
Mar 14, 2011
Looking at the output of netstat, I'm not seeing a definitive way to tell which torrent connections are clients reaching in to my machine vs my machine reaching out to the world. Is there a clear way to determine which is which?
View 1 Replies
View Related
May 30, 2011
I recently installed Fedora 15 now, and during installation I set the internet connection manually, then did update and after reboot, the internet connection settings have been removed. Now I can not set because the network connection to the Internet Connection is inactive. I mention that before the update was functional internet connection.
View 5 Replies
View Related
Jul 22, 2011
Is there a way I can count inbound/outbound mails for a particular user? I'm using sendmail as MTA and dovecot for POP3.
View 1 Replies
View Related
Jun 13, 2011
We are planning on rolling out a mail service that will backend a webmail/groupware interface using postfix and dovecot, and we are trying to nail down an architecture for the system. I was hoping I could get some opinions from you good people on the different models we have come up with, and any improvements. To preface this discussion, we use NFS as the backend storage for mail so that clusters of mail servers can be created.
One possible solution is to separate three services, inbound email, outbound email, and message retrieval onto separate servers. We currently run a mail system with 65K users in this manner and it works, but there is a lot of wasted cpu on the inbound and outbound mail servers. where the dovecot servers are doing most of the work.
Another solution would be to combine the dovecot and inbound postfix servers to run dovecot as the local transport agent for postfix with LMTP, giving us quota and sieve capability.
The last solution is to run all three services on the same machine, giving us a single server image that we can clone on demand when we need to add more performance.
The single server, all three services, solution seems to be the simplest to build and manage, but putting all your eggs in one basket like that concerns us. What if there is a sudden influx of mail from our filtering platform, and it slows down all the other processes? What if the NFS server becomes disconnected from the network and the load average on each server skyrockets killing the ability for outbound mail to flow (where a separate outbound mail server would continue running despite this issue)?
View 10 Replies
View Related
Apr 28, 2010
RHEL 5.4 i want to be able to do redistribution of inbound syslog messages to syslogd. as example, my syslog.conf has in it at the end:
*.* @192.168.5.5
*.* @192.168.5.6
my sysconfig/syslog file has "-r" as the only option for syslogd. any messages generated by the localhost will be sent to the two remote servers, but messages that come into this box (udp 514) only get logged locally and do not get sent out to the remote hosts.
you may ask why do i want to do this. because i have several syslog servers (for security purposes) and many of my net devices are configured to send syslog to all the syslog servers, hence each device is sending way too much duplicate udp-514. so i would like to minimize the udp-514 coming out of the devices, have all devices send to a central syslog server, and then central syslog server do distribution to the other syslog servers. others have also called this "syslog proxy". or, if not with syslogd, how to achieve this (preserving the original syslog message host info, etc)?
View 1 Replies
View Related
Jan 13, 2010
We host a web server in which we are hoping to implement some form of traffic redirection based on source IP address, and I am wondering whether the squid proxy built on iptables would be capable of managing this task? Essentially we are trying to redirect traffic from specific set of source IP ranges to a "Your IP has been restricted" type of page at a different IP/FQDN.
View 2 Replies
View Related
Mar 7, 2011
I understand winxp pro limit the inbound connection to 10 and win7 to 20. Is there a limit for ubuntu server?
View 2 Replies
View Related
Jun 21, 2011
I have installed apf-9.1.7 on linux,after installation inbound activites stopped as per the rules defined.I have added port 20,21 (ftp) in IG_TCP_CPORTS,but still ftp is not working from other Pc.
View 1 Replies
View Related
Mar 22, 2011
I have configured a sendmail MTA for incoming mails in a network and by using IPtables i have redirected the traffic internally to other port where one more SMTP by a application is running.Iptables rule:
iptables -A INPUT -i eth0 -p tcp --dport 25 -j ACCEPT
iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 25 -j REDIRECT --to-port 25000
My sendmail config is as below.
Sendmail.mc
define(`SMART_HOST', `relay:host.subdomain.mydomain.com')dnl
dnl # define(`RELAY_MAILER',`esmtp')dnl
[code]...
View 2 Replies
View Related
May 20, 2011
I have a system running 11.04 and it is dropping packets on the hardwired ethernet interface to other systems on the LAN, only in the inbound direction. It drops packets every 5 seconds. I verified this with iperf. Outbound packets pass with no problems. The network card in this system is a Broadcom Corporation NetXtreme BCM5752
View 9 Replies
View Related
Aug 5, 2010
Anytime someone tries to send me files over YIM or AIM when I am using Pidgin 2.7.5 on Arch Linux, it fails mid-transfer, telling me that they cancelled, and telling them that I cancelled. The same computer using Pidgin on Windows manages to transfer these files successfully.Is there some sort of checklist for these issues?
View 4 Replies
View Related
Mar 21, 2011
so I'm really new to using Linux, and I searched the forums, but most people seem to have trouble sending mail, not receiving it. When I send mail from the CLI, it gets delivered fine (from travis@travishoward.net) But when I try to reply or mail to the server, I get this message back:
Code:
----- The following addresses had permanent fatal errors ----- <travis@travishoward.net>
(reason: 554 5.7.1 <travis@travishoward.net>: Relay access denied)
[code]...
View 2 Replies
View Related
Apr 9, 2011
I am new to this forum and essentially new to Linux, (I used unix between 95 and 99) but the cobwebs are still very thick. I installed Ubuntu 10.10 on an extra PC. I have it pretty much as I would like it now, except for email. I am trying to use Evolution and it is sending mail fine. I cannot receive email. I believe this is because my DSL provider, Windstream.net, says
they support only Outlook and Windows Live mail. I could be way off base, but it seems that it should be able to work. When I mentioned Linux, it basically shutdown their help. I have email through them on Windows 7 on another PC. Is there some way around this so I can use the email address xxxx@windstream.net ? Oh, they use pop3 and require authentication, which is what I have configured. I do not get any error messages, just never get the email. Perhaps another email package?
View 5 Replies
View Related
Mar 19, 2010
I am failing to receive e-mails on client machines. My server has linux Red Hat 7.3. Can you help me with linux command to view sendmail configuration.
View 1 Replies
View Related
Feb 26, 2011
as $1 $2 represent first and second argument..for example- in a shell script..../commfile file1 file2 file3 now in commfile i want to receive files by running a loop...like
for (i=1;i<$#;i++)
do
cat ${i} //help me here
echo do u want to proceed
[code]....
View 9 Replies
View Related
May 5, 2010
I have a question, on my firewall at work I am seeing a constant flow of denies from many different source IP addresses, of tcp/udp destination port 53372 & 53375.What in the world is that, and why these two ports over and over
View 1 Replies
View Related
Feb 1, 2011
I'm simply trying to make a little restriction on www packets under two rules:
1. Allow inbound/outbound www packets (works!)
2. DROP inbound traffic to port 80 from source ports less than 1024. (DOES NOT WORK!)
Now, technically, when i use hping to test my rules, hping3 192.168.100.100 -S -p80 -s 1023 I should NOT receive any packets. However, i still receive packets, which means my rule that says less than 1024 does not work. (see below)
And this is my iptables rules in shell-script so far:
#!/bin/sh
DEFAULT_NIC=eth0
SERVER_IP="192.168.100.100"
ALLOWED_WWW_PORT=80
IPT="/sbin/iptables"
[Code].....
View 1 Replies
View Related
Mar 17, 2011
each time my linux is booting, it check something like eth0 and something else. but there is something i write below that fail... Code: could not receive return value from daemon proccess?
View 3 Replies
View Related
Jun 15, 2011
how I can receive emails about a cronjob execution or where to go to read about that? I am using CentOS 5.4.
View 2 Replies
View Related
