Cisco 1811 and dual WAN (failover if possible)

mkmorris_01 · ‎01-07-2011

Hi All,

I can get around IOS, but I am by no means an expert. I feel so smart because this morning I was able to manually set the speed and duplex on one of the WAN ports to match our new 10Mbit fibre

Anyhow, here's the deal...

The current provider, Bell Nexxia supplied us with an 1840 router which has it's own IP and routes a contiguous /29 for my own use. I currently don't use it as strict routing - rather my servers "outside" interfaces are all on non-routable IP's and I just use firewalling and NAT on the 1811 to route the appropriate IP and TCP ports to the appropriate internal server and use Nexxia as the default route.

My new provider which I want to use as primary gave me an ethernet jack. I've got the second WAN interface on the 1811 to be the "customer router" IP address and the speed and duplex is set appropriately, I can ping it, all is good. But... how in the heck do I tell it to recognize a non-contiguous address space, on a whole other subnet? The IP's route to my 1811, but I am unsure how to tell it that x.x.x.x should NAT over to one of my internal servers. Do I just setup NAT rules in the same way that x.x.x.x goes to 10.10.10.15 port 25? Or do I have to setup a routing rule?

The kicker is, I would like to also use the old one as failover (but I am not dead set on this, the contract is up in 6 months and it is dead slow anyhow).

I can post configs and whatnot.

I do have support / maintenance - is that the best route to go with in terms of this request?

Thanks in advance,

Michael

paolo bevilacqua · ‎01-08-2011

That is often asked.

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a0080950834.shtml

Note i really recommend you locate a reputable consultant or certified Cisco partner to configure and administer your network.

You risk to cause major toruble to you users if you don't,

mkmorris_01 · ‎01-11-2011

Hi Paolo,

I contacted a local CCNA and it is what I thought. Since my second (new) ISP did not provide a router to route the address space, I need to provide my own. I am going to re-purpose the 1811 to be the edge router utilizing my ISP "Customer Router IP" and it will route my "Customer Assigned Netblock" to a new router/firewall. The 1811 is a little slow at it's current task anyhow with NAT on a 3mbps line, so it will strictly become a router. It's max speed is 35mpbs using minimal services anyway, I don't think it will be able to keep up to NAT/IPS and Firewall at 10Mpbs.

The 1841 which was supplied by my previous ISP will stay where it is, binding the two T1's together. The 1811 and 1841 will pretty much be doing the same thing, routing.

I'm going toget an ASA 5505 for failover/nat/IPS at the edge of my internal network, and then it will talk directly to the 1811 and 1841. I'll configure it for IP SLA to determine when something upstream of the 1811 fibre (dns server maybe, haven't decided) goes down and to switch over to the backup 1841 t1's.

Cheers,

M

mkmorris_01 · ‎01-11-2011

Hi Paolo,

I contacted a local CCNA and it is what I thought. Since my second (new) ISP did not provide a router to route the address space, I need to provide my own. I am going to re-purpose the 1811 to be the edge router utilizing my ISP "Customer Router IP" and it will route my "Customer Assigned Netblock" to a new router/firewall. The 1811 is a little slow at it's current task anyhow with NAT on a 3mbps line, so it will strictly become a router. It's max speed is 35mpbs using minimal services anyway, I don't think it will be able to keep up to NAT/IPS and Firewall at 10Mpbs.

The 1841 which was supplied by my previous ISP will stay where it is, binding the two T1's together. The 1811 and 1841 will pretty much be doing the same thing, routing.

I'm going toget an ASA 5505 for failover/nat/IPS at the edge of my internal network, and then it will talk directly to the 1811 and 1841. I'll configure it for IP SLA to determine when something upstream of the 1811 fibre (dns server maybe, haven't decided) goes down and to switch over to the backup 1841 t1's.

Cheers,

M