Two ADSL Line , how to use second line as a backup?

[j.nathan]

Hi there everybody , i need some info regarding below network connections. We have 2 ADSL Lines
Currently we are using windows mobile pdas to connect to a computer PC1 in our network.

PDA -> router wan ip ( ADSL1 ) -> port forward to PC1 ( pc1 192.168.2.2 ) ( pda uses udp protocol i think )

Problem: Program we use on our pdas is custom and everytime we want to make a change company is talking £10,000 and support is rubbish leaving us no option to stop working with the company due to so many problems and now i am trying to overcome a problem which is when our adsl is down pdas cant connect to our network.

PDA's connection settings has remote address and port number only. So far i have tried following;
- Entering ADSL2 wan ip into pda's connection settings and pda connects fine but then again using only one Adsl connection and doesnt solve the problem incase we lose connection on ADSL2
- Created dyndns free domain and entered into remote address in pda , free domain works when using computer but not when using pda so i am assuming domain names doesnt work in pda remoteaddress setting. Reason i tried domain name was at least incase connection goes down i could of update ip number in dns which would of allowed our system to work again.

Question: If i buy or get a static ip from one of the isps ( dsl connection 1 for an example ) for PC1 (computer pdas trying to connect ) and have a dual wan router that can take 2 dsl connections , will this work.if not any information will be greatly appreciated. I can create a diagram if needed. Thank you.

 

[drebo]

You need BGP to make this work properly. There is no other way to use the same IP address with two different providers.

 

[j.nathan]

You need BGP to make this work properly. There is no other way to use the same IP address with two different providers.

Thanks for the reply , i am not familliar with BGP. Also my aim wasnt to set same static ip on router level , just needed to find away to use 1 static ip to reroute traffic back to my network similar to dyndns.

instead of
username.dyndns.org - > 100.1.1.1 ( ADSL 1 )
............................ - > 100.2.2.2 ( ADSL 2 ) Used only when ADSL 1 is down

It could be
150.100.100.1 - > 100.1.1.1 ( ADSL 1 )
150.100.100.1 - > 100.2.2.2 ( ADSL 2 ) Used only when ADSL 1 is down



If answer is same i stand corrected , just making sure i explained myself correctly. Thanks again.

 

[Modelworks]

First you need to separate the modem for each line from the router.
so you need 2 modems, 1 for each line that each output their own ip address, dns, etc Just plain modems, nothing fancy. for ADSL these work well, they are bridges without all the firewall and routing functions. You would need 2.

http://www.amazon.com/Zoom-ADSL-Brid.../dp/B003ULYIKY

Next you need a router that can do auto fail over. It basically has 2 ports for WAN. You specify which is primary and if it detects the primary has failed it will switch to the secondary automatically or you can have it use both to increase bandwidth.

http://www.amazon.com/Duolinks-SW24-...9970127&sr=1-2

Your users would never need to know what DSL line they are using the router will handle that.

 

[drebo]

Modelworks, he's connecting from the outside to the inside, and wanting to do to two different ISPs without having to reconfigure the outside device.

This can be done with DNS, but only if the application properly supports SRV records. If it does, it will test each successive entry before settling on the highest weighted one that works. If it doesn't support SRV records, your only option is to use BGP.

You already mentioned that specifying a host name in the "address" portion of the application DOES NOT work, so that leads me to believe that the application doesn't support DNS A records which are much simpler than SRV records. This means that it's unlikely to work at all.

Perhaps you can get the software manufacturer to add a "backup server" setting. If not, you are left with BGP as your only viable option.

 

[j.nathan]

First you need to separate the modem for each line from the router.
so you need 2 modems, 1 for each line that each output their own ip address, dns, etc Just plain modems, nothing fancy. for ADSL these work well, they are bridges without all the firewall and routing functions. You would need 2.

http://www.amazon.com/Zoom-ADSL-Brid.../dp/B003ULYIKY

Next you need a router that can do auto fail over. It basically has 2 ports for WAN. You specify which is primary and if it detects the primary has failed it will switch to the secondary automatically or you can have it use both to increase bandwidth.

http://www.amazon.com/Duolinks-SW24-...9970127&sr=1-2

Your users would never need to know what DSL line they are using the router will handle that.

Thanks for the reply , i believe this setup is more suitable for outgoing connections rather then incoming connections as i can only insert 1 ip number in program we use on our pdas. PDA program doesnt connect via dns name so this is why i have to use a single ip number. I might need a hosted ip else where on the net and have them reroute to my chosen ADSL line. Although i am not sure such service exists.

Suppose i have your setup and for an example setup two network cards in PC1 which is the computer all pdas connect to. One network card can be internal , if i have a static ip can i put static wan ip on second network card as that would solve the problem as PC1 will be having dual adsl line access and can be reached at second nic address ?

 

[gsaldivar]

Internet:
pda > isp static ip > static redirect to dyndns domain* > dyndns domain redirects to whatever IP is set by the dyndns client*

Server LAN:
server > dyndns client anywhere on server LAN (or use a router that supports failover dyndns update > router with dual-WAN failover capability > WAN 1 / WAN 2 > internet

* you may have to experiment if you have specific port requirements

 

[j.nathan]

Going by "Drebos" suggestion "using BGP system" , i have prepared a list of companies to contact today which technology is called Ip Transit / Static Delivery using BGP which they give you a ip number and connect to their backbone so they do all routing and costs £90 a month. Lets see how it goes.. Thanks for everyones input.

 

[ViviTheMage]

Cisco could do it, but it wouldn't be all that easy.

 

[jlazzaro]

Going by "Drebos" suggestion "using BGP system" , i have prepared a list of companies to contact today which technology is called Ip Transit / Static Delivery using BGP which they give you a ip number and connect to their backbone so they do all routing and costs £90 a month. Lets see how it goes.. Thanks for everyones input.

you would have to cancel your DSL services and subscribe to multiple physical hand-offs from the static delivery provider...

 

[Modelworks]

I might need a hosted ip else where on the net and have them reroute to my chosen ADSL line. Although i am not sure such service exists.

Easiest way to get a static ip is to go through whoever provides your ADSL line. Failing that you would need to purchase a static ip from a hosting service and have it set to redirect to the current ip. Most web host sell static ip with hosting.

 

[Emulex]

ebay xincom
hotbrick
chinese clones of such

they have 2 or 16 link models that work well. been using the $150 (new) xincom for over 4 years now. 2 T-1's (bonded) + comcast business.

works great. can get them used for $50-100.

I'd like to try 16 port model with 3G and 4G backups too.

T-1 = ssl, default traffic in, smtp traffic in/out
comcast = ftp,http preferred in
3g/4g = backup in case both above fail.

 

[j.nathan]

Thanks for all replys , contacted few places and waiting to hear from them, i ll postback when i receive more informartion.