HOW VLANS IS STRETCHED OVER A FIREWALL BETWEEN DC AND DR

[Isaac001]

Dear community,

If we have a servers behind a dc firewall as shown in the topology attached, how do we stretch vlans over the dc and dr site yet there are layer 3 devices in between? 

Yours thankfully,

Isaac.

[Kasun Bandara]

@Isaac001 hello, in this topology you can use VXLAN.

[Isaac001]

Hi Kasun,

Thanks for the prompt response.

In this case what essentially is vxlan doing to overcome the challenge? Thats the concept am trying to get through my head. Are firewalls,routers obstacles to vlan stretching, why? what's the ideal vlan scretching scenario? kindly expound,thanks again!

Regards,

Isaac.

[Kasun Bandara · Accepted solution]

@Isaac001 hello, VLAN is Layer 2 network. routers/firewalls are demarcating the L2 domains and creating L3 domains. you cannot share L2 domain through L3 domain without protocol like VXLAN. you can learn more about VXLAN in this link

https://www.cbtnuggets.com/blog/technology/networking/what-is-vxlan