The tag has no usage guidance.

learn more… | top users | synonyms

6
votes
1answer
913 views

Postfix configuration - keep the envelops

I have a postfix server that delivers mail and send a copy of the outgoing mail to a second server for content analysis using the following configuration (addresses and IPs have been replaced): ...
5
votes
2answers
5k views

What's ssh port forwarding and what's the difference between ssh local and remote port forwarding [duplicate]

I feel confused about ssh port forwarding and the difference between ssh local and remote port forwarding. Could you please explain them in detail and with examples? Thanks!
5
votes
0answers
89 views

Linux iptables ssh port forwarding (martian rejection)

I have a Linux gateway performing NAT for my home network. I have another network which I'd like to transparently forward packets to, but only to/from specific IP/ports (ie. not a VPN). Here's some ...
4
votes
1answer
113 views

unable to connect to forwarded port over ssh

I have two servers. Server 1 has access to an Oracle instance on a server I have permission to hit but not login to via SSH. I would like to use SSH port forwarding to connect from server 2 to server ...
3
votes
1answer
1k views

TCP forwarding over SSH using non-root account

I've setup TCP forwarding over SSH using the following command: ssh -N -L 1234:10.0.2.2:1234 root@10.0.2.1 This works no problem. So I decided to create a non-root account user1 on 10.0.2.1 to do ...
3
votes
3answers
1k views

X11 forwarding through SSH

I have been playing around with X11 forwarding the past few hours and so far I've managed to forward my desktop pc's X Server to my laptop, using X11VNC as server and X2VNC as client. X2VNC uses ...
3
votes
0answers
221 views

How to forward libnotify to growl

I'm looking for a simple solution to forward libnotify notifications (from knotify4) to a remote growl servers (running on Windows and Android). So far I'm only able to send remote growl ...
2
votes
3answers
2k views

forwarding web traffic through a vps running on Ubuntu in another country

I've got a vps in another country. And I'd like to forward all my web traffic through it. I know there are commercial options available in the market but I'd like to do it by myself for the sake of ...
2
votes
1answer
1k views

How do i fix the to address when forwarding with mail/exim?

I am using debian squeeze (i believe, the box doesnt really say) i config exim4 to use gmail and put root: someuser in /etc/aliases then put my email address (name+box@gmail.com) in .forward I ...
2
votes
2answers
622 views

How can I use procmail to modify the body of an email and then forward it to an external address?

I'm struggling to get procmail to first transform, and then forward, a received email. Here's what I'd like to do: :0 f | ~/bin/encryptemail.pl | mail foobar@gmail.com That is, I want to run the ...
2
votes
0answers
15 views

Can I use iptables to forward between interfaces without setting /proc/sys/net/ipv4/ip_forward?

Can I use iptables to forward between interfaces without setting /proc/sys/net/ipv4/ip_forward? I want a secure default of not forwarding anything and then specifying exactly what should be ...
2
votes
0answers
32 views

SSH - Unable to access local forward from another host

I have a VPS with 2 public IPs (assume 1.1.1.1 and 1.1.1.2) I am trying to do a local tunnel to my router on my VPS bound to the second IP, and then access it via another machine. I do the following ...
2
votes
1answer
58 views

Packets not forwarded due to second routing table

I've just spent about an hour trying to understand why my docker containers couldn't connect to the internet, in particular couldn't resolve any DNS names. By now I've found a workaround, but I still ...
2
votes
0answers
354 views

KVM guest as default gateway for bridged network

I currently have two vm's both on kvm (virt-manager), both running on separate virtual interfaces (virbr0 and virbr1). The IP of virbr0 is 192.168.122.0; the IP of virbr1 is 192.168.123.0. Both VMs ...
2
votes
1answer
23 views

Is it possible to show on open/forwarded session in KDE?

When I need to do some longer computation, I leave my computer unattended and just lock the screen. When I log in later to see how progress is going from a remote computer using ssh, it'd be great if ...
2
votes
1answer
1k views

Transparent Ethernet over GRE not forwarding traffic

I am running on Linux 2.6.30.9 and have been trying to setup a transparent ethernet over GRE tunnel. The network topology used is as follows: I want to bridge PC1 and PC2 using Transparent Ethernet ...
2
votes
1answer
302 views

Configure courier to forward certain mails to external addresses

I have a debian 6.0 server with courier/courier-mta set up and some local domains. Now I want to create some forwards for some email address that should go directly to external addresses as there are ...
1
vote
1answer
433 views

possible spots to configure BIND-DNS forwarders

i'm investigating our BIND's configuration and can not figure out how it is aware of it's next name server to ask for some domain he's not authorative server for... e.g. home domain is ...
1
vote
1answer
54 views

Pass a value for an input prompt

I do unzip my.zip and if files already exists it asks replace myfile.ext [y]es, [n]o, [A]ll, [N]one, [r]ename: How can I force input for when the command prompts for input? I am aware unzip may have ...
1
vote
3answers
1k views

SSH Agent-Forwarding works, but what about sudo -u username no shell/ permissions? composer

Working on a remote server (A) I want to use my local SSH-Keys to access a repository on another server (B) that is not controlled by me. Generally this works like a charm. I log in as myUsername ...
1
vote
3answers
469 views

Enabling IP forwarding at kernel compile time

I am compiling a kernel for a router. I know a way to enable IP forwarding in an existing Linux system. At compile time, CONFIG_IP_FORWARD is said to do the same task. I am configuring version ...
1
vote
2answers
144 views

iptables ignores other rules after add last rule

I have written these rules in iptables: -A FORWARD -i eth1 -o eth0 -p icmp -m limit --limit 1/hour --limit-burst 5000 -j ACCEPT -A FORWARD -i eth1 -o eth0 -p udp -m limit --limit 1/hour --limit-burst ...
1
vote
2answers
2k views

Redirect mail adressed to specific address to individual mail servers - postfix

My current set up: mailserver1 mailserver2 (both serving the same domain) and user1 user2 I want do redirect all mails which are addressed to user1 to mailserver1 and the same for user2 to ...
1
vote
1answer
40 views

iptables inside bridge

if i have: eth0 (no address) wlan0 (no address, providing wifi-hotspot by 'hostapd') br0 (local IP, bridging eth0+wlan0) eth1 (public IP, providing internet to above by net.ipv4.ip_forward=1) ...
1
vote
1answer
144 views

Transparent proxying of TCP connections on port (mostly, without root access)

I have the Client machine living somewhere on the Internet, and it needs to access a custom port of Target machine (or, initially any port on any reachable machine, but, eventually, particular port, ...
1
vote
1answer
37 views

Again about routing

Have a problem with primitive routing. Have a CentOs with 3 NICs (1 external). I want to confgure forwarding between two internal. Config: eth0 - 192.168.1.105 \ 24 eth1 - 10.10.10.1 \ 25 eth2 - ...
1
vote
1answer
656 views

How can I forward emails from a POP3 account to another SMTP or IMAP account?

I have an email address that I can access via POP3, but which I rarely use. Though it receives quite a bit of email. I cannot use a forwarding feature for this account. Yet I want to forward ...
1
vote
1answer
825 views

iptables forwarding between subnets

I want to forward traffic between two subnets, I'm not very familiar with iptables. The forwarding works except when iptables is enabled. There must be something wrong with the rules, though ...
1
vote
1answer
2k views

Server inbound email forwarding

I have been struggling to get this to work for a little while now so I have come in the hope of getting a wee bit of help. I am running redhat 6.3, and using the machine as a webserver. My question ...
1
vote
0answers
37 views

How to preserve mime type in CUPS forwarding?

I installed a small CUPS printer which accepts only application/postscript and converts this into a bitmap. Using a generic postscript printer driver I can directly print to this device without ...
1
vote
0answers
99 views

IP packet forwarding in Debian

I have a physical network set up with machines A←–→B←–→C.  IP and Ethernet configurations are summarized as following: A(eth0: 10.10.10.2) ←—→ (eth0: 10.10.10.3)B(eth1: 192.168.0.3) ←—→ (eth1: ...
1
vote
0answers
51 views

openbsd: mpls provider doesn't forward packets

Can anybody help me with next question: I am trying to get mpls test network up like in http://lteo.net/blog/2013/09/03/a-small-mpls-test-network-built-with-openbsd/ or ...
1
vote
0answers
132 views

How to access Transmission runing behind a NAT from external PC

I have two PCs at two different places. Ons is behind a firewall I cannot (place X) control and the other is at my home. Transmission has a way of adding/ removing torrents using a web interface. ...
1
vote
0answers
158 views

Forwarding traffic through an OpenVPN tunnel

I'm attempting to set up a Raspberry Pi (192.168.1.118) in such a way that it allows all traffic that uses it as the default gateway to be pushed through an external OpenVPN tunnel (Private Internet ...
1
vote
1answer
138 views

iptables routing

I believe this question has been answered a 100 times before, but I'm almost sure that I'm searching into the wrong direction. My desired setup is the following: I have a virtual host using KVM and ...
1
vote
0answers
119 views

Is it possible to move established connections on one port, to another without dropping data? [closed]

this problem has been bugging me for a couple of days now. I can't figure out a good enough solution using iptables without having dropped packets. So here is the back story. Say I have a client ...
1
vote
0answers
225 views

Reverse ssh-agent forwarding and unlocking remote keys with your local keys

So the following two things should both be possible to do with ssh the question is just how difficult they would be and I'm hoping someone can give me an easy answer. 1) Suppose I have several ...
0
votes
1answer
1k views

Strongswan forwarding traffic between two IPsec tunnels

Given a remote (centralized) VPN server with a StrongSwan IKEv2 setup with external static IP: centralized server internal IP 192.168.1.65, network 192.168.1.64/27 And two gateways doing NAT for ...
0
votes
0answers
70 views

I can't ping the gateway

The network error is that I can't ping the gateway after ip forwarding configuration. Here's the my configuration: linux microcore(server)(First PC) sudo su ifconfig eth0 192.168.2.200 netmask ...
0
votes
0answers
98 views

openvpn: iptables not forwarding

I have the following topology: And I'm following the iptables rules listed on https://community.openvpn.net/openvpn/wiki/BridgingAndRouting Here's the output of iptables -L -v Chain INPUT (policy ...
0
votes
1answer
62 views

Forward traffic from first to second server

I have 2 Servers, 1 normal Server without ddos protection and 1 ddos protected v-Server, i try to forward traffic through the v server to the main server. So if someone access to my v-server like tcp ...
0
votes
1answer
197 views

Forward traffic coming into dummy interface on to another interface(?)

Can I forward traffic coming into a dummy interface on to another interface? Or is it not a real interface at all even? Chain FORWARD (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot ...
0
votes
1answer
22 views

How to redirect with nginx

I have some http servers running in different ports, but I want to access them this way: 192.168.178.42:80/foo to access 192.168.178.42:8080 192.168.178.42:80/asdf to access ...
0
votes
1answer
270 views

How to redirect all request to specific ip address in ubuntu

How to redirect all request to specific ip address in linux I have tried following command but its not working sudo iptables -t nat -A PREROUTING -d 0/0 -p tcp --dport 80 -j DNAT --to-destination ...
0
votes
0answers
54 views

how to use postfix alias for sending email

I am not this question has been asked or not, I have postfix running with MySQL and recently i have created "support@example.com" alias email to multiple folks get email, just like distribution list. ...
0
votes
1answer
244 views

VPS: How to forward traffic to devices from public IP

My goal is to set up a public IP for a Android Smartphone which is running an "IP Cam" software - the interface can be accessed in local network on (example) 192.168.0.2:8080 - But it has no public IP ...
0
votes
0answers
205 views

Get real IP after OpenVPN tunneling

I try to route traffic from one Server to another using OpenVPN. In the end users should only connect to the forwarding machine. It basically works using this iptables rules: iptables -t nat -A ...
0
votes
1answer
96 views

Connect to other devices under same AP isolated network

I am trying to debug my android application under a public wifi network. The network seemed to have AP isolation on so I can't connect to my android device using my notebook. However, both of my ...
0
votes
1answer
180 views

Job started by procmail does not appear in ps-output and cannot be stopped, even not after reboot

For testing purposes I called procmail by my .forward file |/usr/bin/procmail and by the rules in .procmailrc it started a job named "start", which was simply an infinite loop while true do ...
0
votes
1answer
152 views

Blanket blocking SMTP with whitelist

So using a VPS environment, whereby we need to block outbound SMTP by default (spammers), with the ability to unblock when needed. We have found some scripts eg: iptables -I FORWARD 1 -d $VPS_IP -p ...