VSS and VPC - which is better?

[Maivoko]

VSS use Layer 3 port channel, VPC use Layer 2 port channel , what are difference between Layer 3 port channel and Layer 2 port channel in commands? which port channel is better? are VSS and VPC diagram the same?

VSS and VPC , which is newer? which is better? if VSS is better , does it mean Catalyst 3850 better than N7K?

NSF with SSO can prevent route flapping, but I did not find people configured NSF with SSO in N7K, why?

I find nsf need to used with BGP or OSPF etc routing protocol, does these BGP and OSPF only used for management network only for C3850 use NSF with SSO? such as BGP peer between active and standby N7K or C3850?

[M02@rt37 · Accepted solution]

Hello @Maivoko,

Both VSS and VPC provide redundancy and increased bandwidth, but they are tailored for different hardware platforms.

Regarding which is "better," it depends on your specific use case and the hardware you have. There's no direct comparison between the Catalyst 3850 and Nexus 7000 since they target different markets and use cases.

The reason you might not see it commonly configured on the Nexus 7000 might be due to various factors, including the specific deployment requirements, potential interoperability concerns. 

BGP and OSPF can indeed be used in conjunction with NSF with SSO for both Cisco Nexus switches (like the N7K) and Catalyst switches (like the C3850). These routing protocols allow for seamless failover and continuity of routing information during a switchover event, contributing to high availability.

[Maivoko]

which markets and use cases do VSS and VPC target at?

Layer 3 port channel means downlink device, access layer or distribution layer are also Layer 3 switch router, does it means using VSS the cost is also expensive?

what specific deployment requirements for N7K to use NSF with SSO?

4500 switchover time shorter than 6500 , does it mean 4500 better than 6500 to use NSF with SSO?

[M02@rt37 · Accepted solution]

@Maivoko,

VSS is a Cisco technology primarily targeted at the campus and data center environments. It's designed to provide high availability and simplify network management by combining two physical Cisco Catalyst 6500 switches into a single virtual switch. This enhances redundancy, load balancing, and simplifies network topology, making it suitable for environments where high availability is crucial.

vPC is a technology used in data center environments for Cisco Nexus switches. It allows two Nexus switches to be paired together, presenting themselves as a single logical switch to downstream devices. vPC enhances redundancy and provides a more efficient use of network resources by enabling active-active links to devices like servers or other switches.

L3 port channel involves configuring a link aggregation with L3 routing capabilities. This is often used in distribution and core layers of a network to achieve scalability and efficient routing. It doesn't necessarily imply higher costs, but it's typically implemented in larger, more complex networks where routing at the distribution/core layer is necessary.

A shorter switchover time is generally better for network continuity. If the 4500 series switch has a faster switchover time compared to the 6500 series, it could indicate that the 4500 series might provide better NSF and SSO capabilities in terms of minimizing network disruption during control plane failovers. However, this is just one factor to consider, and the overall suitability of the switch depends on other features, scalability, performance, and your specific network requirements.

[balaji.bandi]

VSS  used in Campus network - Models like Cat 4500 / 6500 / 6800

SVL - replaced VSS and new term for Cat 9400/ 9500 / 9600 switches.

vPC used in DC Switches expecially with Nexus models

so they are not same - you need to choose depends on use case.

[Maivoko]

VSS and VPC both are also target at data center and campus network, and both provide redundancy

market is the same. The only difference is only VSS for larger network when more sites connected with C3850

if this is only a small site, there is simply no difference. Usually there is no frequent and large dynamic change in routes. It look like VPC better than VSS.

[M02@rt37]

Hello @Maivoko,

Depend of the type of the site, depend of the Switch's type (series), depend of your context ; you find the "best" according to these dependencies. It is not a question of performance or something like that.

[Maivoko]

which type of site use VSS or VPC?

is there specific solution?

[Joseph W. Doherty]

VSS vs. vPC depends platforms being used.  If select certain devices based on site, that may also be how you select between these two technologies.

Also keep in mind these two technologies, and stackable switches, each bring along their own "baggage".

[Joseph W. Doherty]

". . . what are difference between Layer 3 port channel and Layer 2 port channel in commands?"

Duh (sorry, couldn't resist), L3 port channel is configured for L3 while L2 port channel is configured for L2.

Seriously, what are you asking?  A list of commands unique to each (L2 vs. L3)?  How each command works?

BTW, you do understand, L3 port channels are also L2?  You also understand VSS can support just L2 port channels?

"which port channel is better?"

Oh, depends on what you consider "better" and even then, for like usage cases, not much different.

"are VSS and VPC diagram the same?"

Depends what the diagram wants to emphasis.  For either, I usually more interested in what on both ends of the port-channel, then whether it's L2 or L3.

BTW, although you're asking about VSS vs. vPC, each is limited to specific platforms, but similar in capability would be provide by stackable switches supporting port-channels across stack-members (this would be most like VSS [and its derivatives]).

"VSS and VPC , which is newer?"

Hmm, don't recall.  Possibly VSS.(???)

"which is better?"

Again, depends on what you consider is "better", for but most use cases, little difference.

"if VSS is better , does it mean Catalyst 3850 better than N7K?"

Firstly, the 3850 is a stackable switch which does support multi-member port-channels, configured as L2 or L3.

I recall (?) reading VSS was later added to 3850s, but, I believe, its limited to two physical switches and cannot benefit from the bandwidth possible between 3850s in a physical stack.

"NSF with SSO can prevent route flapping, but I did not find people configured NSF with SSO in N7K, why?"

Could be those "people" don't consider route flapping likely, and believe it's not worth the effort.

Or, those "people" don't know how to.  Or, NSF isn't always supported on all platforms, requires (somewhat?) neighbors to also support it, and perhaps, it's not supported on a Nexus, or has additional limitations because with Nexus, generally, you still have two logical units.  vPC, I believe, is focused on supported FEXes.

"I find nsf need to used with BGP or OSPF etc routing protocol, does these BGP and OSPF only used for management network only for C3850 use NSF with SSO? such as BGP peer between active and standby N7K or C3850?"

Well, cannot really comment on what you "found".  What you found might be ideal for whatever network you've encountered using it, or maybe not.

[Maivoko]

is there any reason such as looping, speed , security or whether prevent route flapping, vlan flapping etc for choose layer 3 or layer 2 port channel ?

[Joseph W. Doherty]

Versus a single link, L2 or L3?  None I'm aware of.