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I am trying to figure out if an L3 switch is able to act as a switch and as a router at the same time for the same packets. Consider the following architecture: enter image description here

I would like to set up VRRP for both sides so that each side sees only "1" IP address. Is it possible to configure somehow the L3 Switch to act as a switch and as a router so that I can set up VRRP? The logical architecure would be like this so the logical red box would be the actual L3 Switch: enter image description here

If I set up one port as routing port and one port as switchport in each L3 switch, would it work?

To summarize, it would be something like this: enter image description here

Thank you in advance, if you need any details let me know.

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    VRRP was designed for endpoints, not routers. If you have routers, you can configure a routing protocol between them.
    – Ron Trunk
    Feb 8 at 20:41
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    Again, that is the point of routing protocols -- to find the available path. If one router goes down the routers will learn the new path
    – Ron Trunk
    Feb 8 at 20:47
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    If Switch 1 fails in the top diagram, router 1 has no connectivity regardless of how you configure it.
    – Ron Trunk
    Feb 8 at 20:58
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    FHRPs, like VRRP, fail over very slowly, so they really are not appropriate for routers. Routing protocols, like OSPF, can have a full understanding of the other routers on the network, and they can fail over very quickly. FHRPs are to fool the workstations, but routers use routing protocols to fail over.
    – Ron Maupin
    Feb 8 at 21:42
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    Also, a layer-3 switch has a router in it, so they can run routing protocols, too.
    – Ron Maupin
    Feb 8 at 21:43
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I am trying to figure out if an L3 switch is able to act as a switch for himself.

That's a main point of an L3 switch. It switches on L2 and routes between VLANs.

Is it possible to configure somehow the L3 Switch to act as a switch so that I can set up VRRP?

Provided the L3 switch supports VRRP then yes, that's possible. For full functionality you need to set up an SVI on a VLAN and not use a routed port (since a routed port doesn't support switching in case of failover).

Note that VRRP provides gateway redundancy for end nodes. Routers simply route across common subnets. With more than two network you'd need to provide routes to remote subnets though, using static routes or by setting up a routing protocol like OSPF.

It's easiest to visualize an L3 switch as an L2 switch with an integrated but seperate router. While the switch forwards frames between switched ports and SVIs (but only within a VLAN), the router forwards packets between SVIs across VLANs) and routed ports.

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  • Firslty thank you. In my case and in my network, there would be only 1 Vlan associated to that subnet. But there are two L3 Switches. How would that be ?
    – huseyin39
    Feb 8 at 20:58
  • I comment to my self: so I would set up an SVI in each L3 switch (SVI A and SVI B) for that VLAN . Am I right?
    – huseyin39
    Feb 8 at 21:19
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    With only one VLAN and network, a router (or routing L3 switch) is useless. In your lower diagram, there are at least two networks and routing makes sense.
    – Zac67
    Feb 8 at 21:36
  • Indeed one VLAN for the sub-network between RA, RB and R1, R2 ; the network A and the network 1. Thank you!
    – huseyin39
    Feb 9 at 8:42

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