Question about cisco 2811 and 2 adsl

[klxouthrunt]

I have a cisco 2811 with 2 ADSL (2 wics) and some computer use one adsl and other computer other adsl, and I like to know it it' is possible that when automatically when 1 adsl fails then all traffic goes with other adsl, like a backup

It is possible to manage 2 adsl with 2811 with this action or similar?

Thanks

[jackyoung]

Do you mean two ADSLs for the Internet Access ? If yes, I suggest to use policy-based routing and mixed w/ floating static for two groups of user.

Configure a default route to point to ADSL 1, and floating static to point to ADSL 2. It is used to provide the backup if the ADSL 1 fails, all the out-going traffic will forward to ADSL 2.

Configure a policy-based routing at the LAN of the 2811 and define ADSL 2 as next-hop for user group B (assume user group A will user ADSL 1 for out-going traffic). In normal case, if the PBR examine the traffic and find it is user group B, it will forward the traffic to ADSL 2. Otherwise, it will follow the routing table to forward the traffic to ADSL 1. In case the ADSL 2 down, the next-hop of PBR will down, so the user group B will follow the routing table to access the Internet via ADSL 1.

However, you have to determine the traffic volume and check the CPU loading if you enable PBR. It is a CPU intensive features.

Check below link :

PBR

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a008075fae6.html

Floating static

http://www.cisco.com/en/US/tech/tk801/tk133/technologies_configuration_example09186a0080093d6e.shtml

Hope this helps.

[j.vanwijngaarden]

You could also use two HSRP groups with the track option.

[klxouthrunt]

I have some computer that use adsl 1 and other computer adsl 2, I have used acces-list to make this difference of at the moment to use adsl

My question is what can I use If I want that one of adsl fails, then all traffic could be redirected to other adsl?

I have cisco 2811 with 2 wics adsl

Thanks

[jackyoung]

Hi Klxout, did you check my response and any comment on it ? It should work but a little bit complicated.

PBR + floating static can suit your requirement. In PBR, if both ADAL links up, user group B's traffic will be forwarded to ADSL 2. If the ADSL 2 down, all the traffic will forward to ADSL 1. In floating static, if ADSL 1 down, the router will use floating static route to forward the traddic to ADSL 2.

Please feel free to advise if there is any issue or it does not fit for you.

Hope this helps.