Hello,
I need some help configuring a routing scenario below on the ASA Firewalls only between sites A and B as per diagram (see attached. It can be done using BGP or OSPF but need guidance on which is the best and simplest to configure and how it can be configured easily.
1) I need to apply source NAT to all “user” sourced https connections from WAN via ASR Routers which be using VPN Tunnels. This is to resolve the issue of asymmetric routing under various resilient modes of operation.
2) To advertise (via BGP or OSPF) the Web IP addresses to the ASR routers at the primary site. Static routing will be used to route traffic in to the backup site.
3) Metrics will be applied to the web site advertisements in to the WAN core to designate a fixed Primary and standby site mode of operation.
4) The firewalls will withdraw the advertisements to Routers from the primary site if that site can no longer provide web access. This action will re-route ALL web access to the Standby site.
5) The route advertisements need to be re-enabled to the ISR Routers on WAN from the primary site when web access is restored. This will re-route any NEW connections to the web servers via the primary site, it will not have an immediate effect on existing live connections to the backup site and these will continue to route this way until the dynamic tunnels timeout. The timeout duration is dependent on whether any traffic is flowing over the tunnel so is indeterminate. It should be noted that in this scenario there will be some asymmetric routing but https web site access should not be.
Any help appreciated.
