From: Sydney, Australia
I do this right now (and have been for 3 odd years) with Win2K and ISA2K. Have some "pinging service" (ipmonitor, serveralive etc etc) check an IP for the frame realy serial, or some other way to cehck that each link is up. If perferred link goes down, do a : route delete 0.0.0.0 mask 0.0.0..0 route add -p 0.0.0.0 mask 0.0.0.0 x.x.x.x where x.x.x.x is the new default gateway of your 2nd ISP. as soon as your primary link comes up again set the default route abck to use it.
Due to default routing you cannot have both routes in use SIMULTANEOUSLY. You can sort of work aroudn this by having static routes to certain subnets so you can still access resources at both ISP's but then of course the link to that ISP MUST be up to get access.
You can even do this with a batch file. This is not syntaxically (?) correct, but it gives the idea.
checkroutes.bat ping -n 1 ISP1ipaddress > ISP1.txt find "Reply from" ISP1.txt if errorlevel such that text is found goto ISP1OK :ISP1fail ECHO You could test this again so as to stop link bouncing if the link is temporarily choked route delete 0.0.0.0 mask 0.0.0.0 route add -p 0.0.0.0 mask 0.0.0.0 ISP2gatway goto waitamoment :ISP1OK ECHO ISP1 seems to be OK. You could test for ISP2 to make sure.. :Waitamoment del ISP1.txt ping -n 30 127.0.0.1 REM ping the local box 30 times to induce a time delay :end checkroutes.bat
Run the batch once and it'll keep looping through itself... A bit of a hack but it'd work! OF course this would bugger up and published mail-servers etc you may have but you could alwags vbscript those changes as well..
So are there directions somewhere where I go and find out how to configure my ISA2000 box to allow more than one ISP. Right now my main concern is allowing data to come in from that 2nd pipe and of course return back out that pipe.
I.e. If my VPN goes down RRAS will autopmatically connect to that other ISP's NIC card on the iSA server. Would all traffic then go out that link for the vpn traffic?? Where can I find out how to do this.
The Rainwain, rainconnect product actually works very well for that function I have tested it. The only complaint that I have about it, is that it adds a lot of latency for some reason. I might normally have 80ms response time with rainconnect that causes it to run at 400ms or higher. Let me clarify, for outbound utilizing multiple ISP connections and balancing out traffic. We don't specifically need inbound, this is for our web surfers.
I just finished a fairly large rainconnect deployment and it is a decent product (for $4000). It does great for in and outbound ISP redundancy. However, I have decided that never again will I do large scale web hosting behind rainconnect using it for inbound DNS and ISP redundancy. We have to do triple entry for DNS.
1. Internal DNS with pointers to the internal IP of the web servers
2. The load balanced DNS in Rainconnect that just does A and MX records (no reverse lookup, PTR, or anything else)
3. The external DNS which has all of the records for the hosted sites. Rainconnect forwards the DNS requests that it cannot answer to this server.
Over all it works but the webmaster who runs the DNS is about ready to throttle me
Lessons learned, I may never again to large scale web hosting behind NAT.