11-19-2002 05:05 PM - edited 03-02-2019 03:01 AM
I have a 3640 that have 3 channelized E1 interfaces and one fast ethernet interface.
My problem is that I do not have CPU do do alll this job. My CPU average is 85~98% during work hours.
The router have ip cache-flow enabled on all interfaces but not in FastEthernet
my question is:
its better or worst for the CPU cache-flow enabled in fast-ethernet interface?
I dont do nothing yet because is a production router and I dont want to discover
that I was wrong in the real life.
Tanks for all
11-20-2002 01:34 AM
Did you explicitly configure this, if so are you exporting the flows.?? If you are not doing this then i would suggest making sure CEF is enabled by just issueing a sh ip cef command, if it is not enabled it will tell you.
CEF is a great switching mechanism and should reduce CPU burden as FIB and adjacency tables are built based on routing and ARP info so.
If you also do a sh ip proc | exc 0.00 it will indicate which processis taking up CPU also look at your buffers and see how many misses there are etc. It sounds as tho your router is busy processing switching which is a huge burden on CPU resources for a high throughput router.
The command which is hidden "sh interface switching" will indicate whether traffic is being fast switched or processes switched.
11-20-2002 03:50 AM
Yes, we are exporting the flows.I cant use CEF.
We are buying a new 3745 350Mhz to make better this work
but we have to wait few months.
One more question about "sh int switching " command
How can I now is the traffic is fast or processes switches?
(see example below)
And as I was write, I want to know if is best or worst have ip route-cache flow enable on a Fast ethernet interface
tanks one more time
sh processes switching example
Drops RP 0 SP 0
SPD Flushes Fast 0 SSE 0
SPD Aggress Fast 0
SPD Priority Inputs 44 Drops 0
Protocol Path Pkts In Chars In Pkts Out Chars Out
Other Process 0 0 22019 528456
Cache misses 0
Fast 0 0 0 0
Auton/SSE 0 0 0 0
IP Process 34997 3486135 14760 2317463
Cache misses 34997
Fast 10127390 1619932064 4930614 2763202294
Auton/SSE 0 0 0 0
CDP Process 3673 1160668 3674 1109548
Cache misses 0
Fast 0 0 0 0
Auton/SSE 0 0 0 0
11-20-2002 03:59 AM
Depending on what code you are using CEF should be enabled by defualt: The Eg: below i have configured both but i am not exporting flows as i do not have a collector.
interface Ethernet3/0
ip address 192.168.0.2 255.255.255.0
ip route-cache flow
crypto map test
sh ip int eth 3/0
Ethernet3/0 is up, line protocol is up
Internet address is 192.168.0.2/24
Broadcast address is 255.255.255.255
Address determined by setup command
MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is disabled
Outgoing access list is not set
Inbound access list is not set
Proxy ARP is enabled
Security level is default
Split horizon is enabled
ICMP redirects are always sent
ICMP unreachables are always sent
ICMP mask replies are never sent
IP fast switching is enabled
IP fast switching on the same interface is disabled
IP Flow switching is enabled
IP CEF switching is enabled
IP Flow switching turbo vector
IP Flow CEF switching turbo vector
IP multicast fast switching is enabled
IP multicast distributed fast switching is disabled
As for the output of the sh interface swtiching, you should see a line that says fast, the IP process line shows the amount of process switching that is done, those are the counters to watch out for, as far as you needing the flow information you will have to stick to ip route-cache flow, however i would look at turning on CEF too.
11-20-2002 04:28 AM
dear Dale,
To enable flow-switching you need to have the command
ip flow-cache feature-accelerate enable in the router
anf the ip route-cache flow command in the interface
To export you have to have also
ip flow-export destination
ip flow-export source
ip flow-export version 5
tank you for the other replies
11-20-2002 04:38 AM
Thanks for your input, i am very well aware all i was saying is i do not have a collector so hence did not config export portion. I was just showing that CEF and FLOW can run together and hence.. should help your cause.. So basically enable CEF.. i am sure would help..
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