Dual-WAN interfaces with 4321 ISR

[Darren Durbin]

Hello,

I've been putting in a good number of Cisco 800 series routers for customers for several years with no issues. I've just had cause to spec a dual WAN router for a customer with two 30Mb/s lines and so went to look at the specs for a suitable Cisco model.

If I look at the spec on a 4321 ISR it lists 2 WAN interfaces ( here ) Being simple, I assumed this meant I could configure 2 WAN interfaces - being used to the 800 series where a WAN interface means a WAN interface, and a LAN interface is listed separately.

Having now seen a picture of the back of a unit it appears that these aren't WAN interfaces, but act as either a LAN or WAN interface, meaning that - as it ships - I can't use this router for a dual-WAN configuration. I would need to add something like a NIM-ES2-4 to allow the built-in interfaces to act as WAN interfaces, then use a port on the NIM to act as the LAN interface.

Is this correct? I am wrong in assuming that if something ( particularly an ISR ) is listed as having 2 WAN interfaces that I could use 2 WAN links whilst still having an interface to connect to the LAN to make it useful?

Thanks!

Darren

[Reza Sharifi]

Hi Darren,

If the hand off from the provider to you or your customer is Ethernet, there is no need to install NIM-ES2-4.  All you need is the on board interfaces that come with the router. The on board interfaces can work as LAN or WAN.  There are 2 10/100/1000 copper and 1 1Gig fiber interfaces.

If you need more than 2 ports than yes you need to purchase a module.

see table-4 in this link:

http://www.cisco.com/c/en/us/products/collateral/routers/4000-series-integrated-services-routers-isr/datasheet-c78-732542.html

HTH

[Darren Durbin]

Hi Reza - thanks for the speedy reply.

Just so I'm clear, despite the data sheet specifying that this router has 2 WAN interfaces, what it actually has is 2 interfaces ( one 1GbE, one dual-personality GbE/SFP ), which can be used as either LAN or WAN.

So, in order to actually use 2 WAN interfaces ( one for each leased line ) I'd need to purchase a module? The cheapest option seems to be the NIM-ES2-4 - all I need is a 100Mb/s connection to the LAN.

Can the MGMT port be used as an extra 'normal' port as you can with an ASA5510?

Thanks

Darren

[Darren Durbin]

Can the MGMT port be used as an extra 'normal' port as you can with an ASA5510?

OK, ignore that bit! Just seen that the management interface is in its own VRF

[farguisito]

Hi Darren,

Finally which choice to select to fix your problem?

Regards.