09-07-2010 02:11 PM - edited 03-04-2019 09:41 AM
Hi, recently i notice that one of our 6509 switches was operating in truncated mode when i looked at this i noticed we had an old flexwan connected to the switch that was not being used, after removing it we are now running in compact mode.
before removing the flexwan I was seeing this.
Global switching mode is Truncated
dCEF mode is not enforced for system to operate
Fabric module is not required for system to operate
Modules are allowed to operate in bus mode
Truncated mode is allowed, due to presence of Standby supervisor module
Module Slot Switching Mode
1 Crossbar
2 Crossbar
5 Bus
6 Crossbar
8 Bus (flexwan)
Module 5 is the sup720-3bxl, shouldn't I have been seeing Crossbar on 5 instead of BUS(Flow-Through)?
after removing the old felxwan I now see,
Global switching mode is Compact
dCEF mode is not enforced for system to operate
Fabric module is not required for system to operate
Modules are allowed to operate in bus mode
Truncated mode is allowed, due to presence of Standby supervisor module
Module Slot Switching Mode
1 Crossbar
2 Crossbar
5 dCEF
6 Crossbar
I guess im not understanding what performance im loosing when i have a classic card installed. For the ouput below with either switching modes I see the same speed.
slot channel speed module fabric
status status
1 0 8G OK OK
2 0 8G OK OK
5 0 20G OK OK
6 0 8G OK OK
As I understand it, all non SFM will use the shared 32 Gb bus but how does having a classic card affect the sup720, what performance was lost when i had a none SFM card installed as compared to having all SFM?
thanks, Paul
09-08-2010 06:47 AM
ra7or wrote:
Hi, recently i notice that one of our 6509 switches was operating in truncated mode when i looked at this i noticed we had an old flexwan connected to the switch that was not being used, after removing it we are now running in compact mode.
As I understand it, all non SFM will use the shared 32 Gb bus but how does having a classic card affect the sup720, what performance was lost when i had a none SFM card installed as compared to having all SFM?
thanks, Paul
Paul
Compact = centralised forwarding of up to 30Mpps
Truncated = centralised forwarding of up to 15Mpps
From the 6500 Architecture White Paper -
Compact Mode
Truncated Mode
09-08-2010 09:34 AM
I guess I trying to understand where the performance is impacted, I'm assuming its at the shared Dbus
level when using Classic and SFM together?
Also I'm trying to figure out why when I have an old flexwan card on slot 8 i see the sup720 in flow through (Bus) switching mode instead of truncated?
with the felxwan
Switch Fabric Resources
Bus utilization: current: 0%, peak was 14% at 22:13:21 edt Sat Apr 4 2009
Fabric utilization: Ingress Egress
Module Chanl Speed rate peak rate peak
1 0 8G 0% 0% 0% 0%
2 0 8G 0% 0% 0% 0%
5 0 20G 0% 0% 0% 0%
6 0 8G 0% 0% 0% 0%
Switching mode: Module Switching mode
1 truncated
2 truncated
5 flow through
6 truncated
without the flexwan:
Fabric module is not required for system to operate
Modules are allowed to operate in bus mode
Truncated mode is allowed, due to presence of Standby supervisor module
Module Slot Switching Mode
1 Crossbar
2 Crossbar
5 dCEF
6 Crossbar
thanks Paul
09-08-2010 09:52 AM
what flex module do you have?
"show module"
Francisco
09-08-2010 12:03 PM
Paul
I guess I trying to understand where the performance is impacted, I'm assuming its at the shared Dbus
level when using Classic and SFM together?
Exactly. As the bit i cut and paste says -
1) compact = header over sent over DBus
2) truncated = header + data sent over DBus
hence the reason Cisco can never give exact figures on truncated forwarding because the data portion of the packet varies.
Jon
09-08-2010 12:52 PM
Jon,
that's what I figured but im glad you got rid of my doubt.
thanks, Paul.
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