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Cisco ASR 1000 - Connecting to redundant switching?


I was wondering if anyone knew whether or not you can connect an ASR1000 to two separate switches using the same VLAN? If this was an ISR G2 I could have used a BVI interface or installed a switch card and used VLANs. BVI and VLAN doesn't seem to exist. A BDI sounds like it could work however I was having problems getting mac-resolution to work using it. At this stage all I need to know is the design and feature to use for this type of design with an ASR.

Basic topology is:


|                    |

DMZ SW #1 ----- DMZ SW #2

|                    |

Firewall #1   Firewall #2

|                    |

Core #1 ------ Core #2

NOTE: DMZ switches aren't stacked so I can't use a port-channel.

Is it possible to connect an ASR like this and have it function? I'm pretty new to the IOS XE platform so any advice is welcome!

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New Member

Cisco ASR 1000 - Connecting to redundant switching?

The answer is it can't be done.

  • ASR does not support bridged-interfaces
  • ASR does not support switchport (same VLAN on multiple interfaces)
  • ASR has a feature called "backup interface" but that isn't usable for GigEthernet interfaces (Serial/ISDN only I believe)

The best option is to stack the switches and run LACP from ASR to Switches. I can't do this as the switches won't stack.

Another option is to run the switches in L3 mode and have separate VLANs between DMZ switch and ASR. i.e. DMZ SW 1 to ASR = 10.1.1.x/24 and DMZ SW2 to ASR = 10.1.2.x/24 and use L3 routing failover.

For me, I am going to cut back to a single DMZ switch as that works in the topology/customer I am working with (single DMZ switch + single ASR router).

Worked with Cisco design team to validate this.