Can we use C9500 Switch instead of ASR 1001-X Router?

[kumardipu84]

Dear All,

We have one ASR 1001-X Routers in the existing environment and we are using BGP as a routing protocol to reach other 20 global locations and OSPF to reach internal LAN. But now we want to use the C9500 Switch in place of ASR 1001-X Router due to fewer 10G port routers.  Could you please help me with whether we can use C9500 Switch in this network topology because C9500 Switch is available in Stock but if we go with ASR then we have to buy ASR 1002-HX?  

As we know that C9500 Switch support BGP and other routing protocol. We are not using advanced BGP configuration in our current topology.

[BDG]

In theory, you can, if you do not plan to use the firewall functionality. There may also be nuances with NAT. L3 switches can quickly route IP packets, mostly local area networks.
https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-9500-series-switches/nb-06-cat9500-ser-data-sheet-cte-en.html

The Cisco Catalyst 9500 Series is the industry’s first purpose-built 25, 40 and 100 Gigabit Ethernet line of switches targeted for the enterprise campus. These switches deliver unmatched table scale (MAC/route/ACL) and buffering for enterprise applications. The Cisco Catalyst 9500 Series includes nonblocking 40 and 100 Gigabit Ethernet Quad Small Form-Factor Pluggable (QSFP+, QSFP28) and 1, 10 and 25 Gigabit Ethernet Small Form-Factor Pluggable Plus (SFP/SFP+/SFP28) switches with granular port densities that fit diverse campus needs. The switches support advanced routing and infrastructure services (such as Multiprotocol Label Switching [MPLS] Layer 2 and Layer 3 VPNs, Multicast VPN [MVPN], and Network Address Translation [NAT]); Cisco Software-Defined Access capabilities (such as a host tracking database, cross-domain connectivity, and VPN Routing and Forwarding [VRF]-aware Locator/ID Separation Protocol [LISP]); and network system virtualization with Cisco StackWise® virtual technology that are critical for their placement in the campus core.

But the Cisco ASR 1002-HX is better suited for an edge device.

[kumardipu84]

@BDG 

Thank you for your prompt response.

you are right, When I study Cisco Doc about C9500 Switches then I thought we can use the C9500 Switch.

We are also planning to buy ASR 1002-HX but we want to use this Switch for 2month till receiving the ASR 1002-HX. 

Thank you

Regards

Dipu Kumar

[Giuseppe Larosa]

Hello @kumardipu84 ,

supporting BGP and OSPF on Cat9500 is not the same as in an ASR 1001-X .

The second one can be equipped with 16 GB of RAM on the supervisor and can support multiple full BGP tables in the order of 800,000 routes each.

The Cat9500 is limited by its own TCAM table size and cannot support so many prefixes in CEF.

The second aspect are the features specially NAT for internet access that is supported on ASR 1000 but not on a Cat 9500 (so I suppose).

So you have to consider these two aspects control plane scalability and security features and NAT.

The Cat9500 is suitable only if:

you are not getting a full BGP table from provider and the link(s) are not used for internet access but only for a closed connectivity between sites like in an MPLS L3 VPN.

In this case with no NAT involved and few routes received from PE node(s) related to other sites the cat9500 could be used.

Hope to help

Giuseppe

[kumardipu84]

Hello @Giuseppe Larosa 

Thank you for your information.

I am sorry, I forgot to mention in the above post. We are using VPLS connectivity between our all locations and in this scenario, ASR routers don't receive any route from PE, ASR routers receive routes that we have advertised from other location ASR routers. 

AS you mentioned above,  it is closed connectivity and we don't use NAT.

Thank you once again

Regards

Dipu Kumar

[Giuseppe Larosa · Accepted solution]

Hello @kumardipu84 ,

yes with VPLS service it is still a closed connectivity model and your devices peer directly between them.

I would say you could use a Cat9500 in this scenario

Hope to help

Giuseppe

[kumardipu84]

@Giuseppe Larosa 

Thank you for your valuable information.

Let me use C9500 Switch in my network scnario and update you with my experience.

Thank you

Regards

Dipu Kumar

[kumardipu84]

@Giuseppe Larosa 

We don't have internet access in this network. we have a separate network for internet access.

Regards

Dipu Kumar