HOWTO access backup external connection from outside

[sorcerer]

hi,

this is a general networking question:

i have a linux server, as a router with a local network, a main broadband internet connection and another cheap secondary internet connection from another provider (for backup and stuff)

now, what i need is to access server from internet via that cheap connection (for diagnostic purposes in case main connection is having a problem), that secondary connection have it's own ip (so, it can be accessed directly from internet) ... any ideea how to do that ?

i have limited experience with iproute2 and advanced routing, and what it think the problem is that default route is on the main connection and even if packets get on second connection they are wrongly send through main connection.

[DrHu]

Create a static IP connection for the secondary server via the web admin page of your router
--then you should be able to remotely connect to it via the Internet: you also would need a remote control program server(host..your server) + client (remote), your Internet connection (any OS windows or mac or Linux..

Or use some of the ideas below..

You can use dynamic dns to keep track of your computer host name (with associated IP address)
http://dnslookup.me/dynamic-dns/

We maintain the #1 list of Dynamic DNS (DDNS) providers online. Dynamic DNS is a method that allows you to notify a Domain Name Server (DNS) to change in your active DNS configuration on a device such as a router or computer of its configured hostname and address. It is most useful when your computer or network obtains a new IP address lease and you would like to dynamically associate a hostname with that address, without having to manually enter the change every time

When people intend to offer a public web server or services, they usually pay for a fixed IP address, which makes it simple for their clients to connect to..
--quite often the static IP for remote connections is not that costly: bandwidth is the killer, which you always have to control/manage in order to contain costs

If it is just a blog type system, then wordpress has a collection of free sites for their users available, into which you can pour a quality web page look
http://wordpress.org/
--even if it is an easily managed blog in reality..

[sorcerer]

thank you for ... interest


Linux server is the router, it have 3 Ethernet cards on it 2 for each internet connection and one for LAN

secondary internet connection have a static ip address and it is working as long as default route is set through that connection (i can connect from outside)

i didn't mention anything about another router and i'm pretty sure this can be done with advanced routing, no need to buy another router (even if is not that expensive)

[DrHu]

[EDIT--start, OK I see that description, I have linux as a router is in your paragrph, I just didn't unscramble it enough
--that's why I like lists, so I can see each piece of reference data [EDIT--end]

So my replay before the edit was..I don't think I mentioned buying another router, however your better description : Linux is the server
--still to connect via an internet connection would require you to be an ISP or hire the same.

Because you still need either the dynamic IP connection or a static IP

--there are of course free dynamic IP services available, static IP would need IANA setup..

http://www.engr.colostate.edu/ens/how/c ... login.html
http://www.mynitor.com/2010/02/07/15-re ... for-linux/
--remote clients NX has a pretty good reputation, speed etc..

http://www.yolinux.com/TUTORIALS/LinuxT ... onfig.html
--for a Linux hosted web, Apache info..

You could also use the hosts file to specify the other computer(s)
-- or a nameserver
http://www.ibm.com/developerworks/linux ... index.html
--that is red hat, but the methodology is similar for any Linux, setting up your LAN (for connectivity..)

i have limited experience with iproute2 and advanced routing, and what it think the problem is that default route is on the main connection and even if packets get on second connection they are wrongly send trough main connection.

That issue is due to the host/connection being seen by the outside as the only connection, the other connections are internal to your network/Linux server
--you might be able to do that by managing a port (port forwarding) to one of the other machines you need to pass-through your LAN (Linux server ) to..
http://linux-ip.net/html/nat-pat-userspace.html

IPTABLES, try DNAT requests to the public IP address
http://linux-ip.net/html/nat-dnat.html
http://nixcraft.com/centos-rhel-fedora/ ... linux.html

[sorcerer]

again, thank you for interest, but ... is a networking problem, not a service problem

linux server have ssh service and i don't need anything more (even that your links are interesting, as general knowledge, but in my particular case, server don't have any graphical environment, i just don't need it at all)
secondary connection is installed as backup but also for diagnostics when is a problem with main connection, so ! port forwarding has nothing to do with my question, port forwarding is a solution to connect to a system BEHIND a router ... what i need is to connect directly to my router, but on "back door" not on front/normal connection

my english is not the best, and i apologize for that, but please don't give me another solution to generically connect to a linux machine, i can connect just fine on ssh service, but what i need is to connect to backup/secondary internet connection, and i need to do that completely independent from main (when main connection may be down or having another problem),

so, let me try again ... maybe this time i manage to be really clear ... Linux server have a main connection, default route is set through it

now, on secondary connection, i set up IP on Ethernet card, but i cannot set default route on it, be cause a tcp/ip machine can only have one default route, therefore, my problem is: i cannot connect to THAT internet connection from outside, and that's what i need to solve !