mouving from router on stick topologie to switch module sm-x

[Aladdin0z]

I am moving from router on stick to an integrated switch module topologie , 

whats the best way to do it , 

where to put the gateways ?

if i deciede to use svi interfaces inside the switch module , how can we insure the routing between the switch module and the router .

i dont know if the router will have a unified routing table that includes switch svi interfaces ?

[Aladdin0z]

Hello  , 

Lets assume that the module in question is a laye two only , witch is SM-X-16G4M2X  .

after digging a little bit in the module reference i can not  know for sur whats the internal port that will be attached to the switch module .

the  question is :

- whats  internal router interface  will be attached to what switch module interface ? 

in the case of the module SM-X-ES3 witch is an l2/l3 module the documentations talks about the internal port mapping in a clear way , 

in the case of the SM-X-16G4M2X the only thing mantioned is

''''  It also, provides 10G-capable internal uplink to central forwarding data plane on modular ISR platforms.'''' and i dont think this is relivent to the internal port mapping ,

with what have been said and what @Joseph W. Doherty  has clarified , i think that this layer 2 switch module does not handle the internal port mapping , if this is true , the options i have fo this senario are :

- cheking the routing table to see if the svi created are automaticaly learned , if its not the case an external trunk link from the module to the switch will be needed . 

- also i will check the MGF is supported in the router end 

bellow  the module installation and configuration guide , check it out @Joseph W. Doherty  please .

Configuring the Cisco SM-X-16G4M2X or SM-X-40G8M2X EtherSwitch Service Module - Cisco

they mention in one phrase that in order to route vlan traffic SVIs can be created in the switch module .

[Joseph W. Doherty]

Yep, reading that configuration guide isn't real clear.

Also, helpful, is the installation guide.

From both documents, these SMs appear to be L2, but support L3, via the router, very much like similar ISR L2 Ethernet modules have in the past.  I.e. The router will likely "see" the physical Ethernet ports, but the router cannot use them until you define a SVI, for a VLAN, mapped to a group of ports.  Once you have the SVI, using the ports would be much like using L2 VLAN ports on a L3 switch, while the router's original routed ports would be like L3 switch ports in non-switchport (routed) mode.

That being the case, the router might still be a routing bottleneck.  (Remember, performance tiers, for a 4331, are 100 and 300 Mbps, and then 2+ Gbps, but the last is highly variable in what you may obtain.  [What's the aggregate bandwidth of your SM's ports?])   However, the reference documentation mentions these particular SMs supports a next-generation switching mode (unique to these SM), but I couldn't find any details what's new about it, beyond you need to reload your ISR to enable this mode.

I did see mention of the 10g MGF connection.

Have you installed one of these module yet?  If so, do you see it's Ethernet ports?

Have you done?:

Connecting to Cisco C-SM-16P4M2X or C-SM-40P8M2X Service Module

Before you can access the module, you must connect to the host router through the router console or through Telnet. After you are connected to the router, you must configure an IP address on the Gigabit Ethernet interface connected to your module. Open a session to your module using the hw-module session command in privileged EXEC mode on the router.

To establish a connection to the module, connect to the router console using Telnet or Secure Shell (SSH) and open a session to the switch using the hw-module session slot/subslot command in privileged EXEC mode on the router.

Use the following configuration examples to establish a connection:

Router# hw-module session slot/card
Router# hw-module session 0/1 endpoint 0
 
Establishing session connect to subslot 0/1

All might be clearer, connected to the router, to "see" how this module presents itself to the router, and what it allows configuration wise, and results of configuration changes.

Heck, I can make guesses about the significance of the SM's next-generation switching mode, but they would be that, just guesses.  Likely, somehow, they are to improve performance, but how?

I suspect that all the SM's might be, L2 wire-speed, at least within the same VLAN, same SM.  If ports are in different VLANs,  same SM, possibly SM will also route between them, without using the router's CPU, and do this at wire speed too.  (In multiple like SMs in the routers, they might be able to also do L2, even L3, between themselves, up to 10g.)

Just now, looking at the datasheet for the C-SM-16P4M2X, believe some of my suspicions are true because:

• Up to 2x 10G of SFP+ Fiber Uplinks with up to 10G connection to MGF switch fabric[1]
  • ^[1] Each SM slot has one 10Gbps connection trace to the MGF switch on the ISR4000 Series router
• Support for local line rate local line-rate switching as also support for direct service module-to-service module communication through the ISR 4K Multigigabit Fabric (MGF), separating LAN traffic from WAN resources.
• ASIC with programmable pipeline and micro-engine capabilities, supporting Layer 2 and Layer 3 forwarding (in conjunction with the router) and Quality of Service (QoS)
• Isolation of LAN traffic and route between ports on the Cisco SM-X EtherSwitch Service Module
• Layer 2 traffic is switched on-board the module
• Traffic can be forwarded between service modules over the MGF without affecting the router CPU

[edit - PS]

From the datasheet, L2 on the SM should be wire-rate.

Where is L3 between VLANs on the SM or between other modules or the router, done?

Bandwidth to other modules, including the router "itself" limited to 10g.  (NB: even for the small card, I count it as providing up to 46 Gbps port bandwidth.)

(Again, without more details on the SM's full [implemented] capabilities, including the full significance of its ASIC [including not listed in the above "UADP 2.0 Mini compliant ASIC"], perhaps these SMs can function much like the 6500's line card DFC, and work in conjunction, somewhat tightly bound, to the router's CPU.  If so, it might be a very huge upgrade to a 4K ISR.)

[edit2 - PPS]

Just did a quick study of UADPs.  The UADP 2.0 mini, appears to be one of the newest variants of the UADP ASICs, and might be why there's the "next-generation switching" about this SM.  (Also, I recall, reading this UADP is use in the Catayst 9200 series.)

I wasn't current on UADPs, but reading about them, I now, believe I, understand what they are and why Cisco now is using them.  This UADP is very likely the "heart" of this SM.  Definitely handles data plane "stuff".  Likely can do L3 forwarding, but unclear how much it can configure itself to do.  I.e. might need a general CPU to set it up, and if it does, the questions are, can the router's CPU do this, and if it can, does it?

Possibly, using that SM, you've "married" a miniature C9200 with your 4K ISR.  Again, assuming you can do L3 through the SM ports, somehow, where is the L3 performed for, between ports on the SM, other modules, to/from the router's built-in ports?

@Aladdin0z I realize front and foremost, you just want to be able to move from your standalone switch to the SM.  That, might actually, from a configuration stand point, be rather easy.

But, when you get pass that, I'm curious whether you'll be able to determine if there any L3 performance differences.  If there are, please post a follow-up.