BDI interface on Cisco ASR 1001-x router

Hi All,

The current setup is

ISP1 ISP2

| |

RTR1 RTR2

| |

SW1-----SW2

​

My switches are cisco also. The switches are not stacked but are connected by a trunk link. If SW1 fails, HSRP will failover to RTR2 but the BGP failover has about a 60 second outage because we have to change ISP. I've been tasked with creating the criss-cross style redundancy using the BDI interface.

https://www.cisco.com/c/en/us/support/docs/lan-switching/integrated-routing-bridging-irb/200650-Understanding-Bridge-Virtual-Interface.html

The documentation doesn't seem to match up to my specific network as I've L3 port interface on the router with an IP address assigned and L3 access port on vlan 100 on the switch side.

I want something like this

ISP1 ISP2

| |

RTR1 RTR2

| X |

SW1-----SW2

​

I've tried to set it up but its causing a loop. The ports on the switch side are access ports but I tired following a forum post changing the switch ports to trunks but I still had issues. The switch is running RSTP. It appears I can only get the ASR router to run ieee. Is this even the correct way to achieve what I want ?

The end goal is to have redundant inside/lan cables (2 cables from each router to the LAN). It's a network design I've seen many times but usually with all L2 or all L3 links.

RTR1 LAN cable1 going to SW1

RTR1 LAN cable2 going to SW2

RTR2 LAN cable1 going to SW1

RTR2 LAN cable2 going to SW2

​

From research online it looks like a few other people have had this same issue moving from BVI interface to BDI interface, some have found a solution but nothing has worked for me so far. Thanks in advance for any help or insight here.