Low Throughput on 1841

[DanielSheppard]

Hello,

We have a 1841 setup with WAN and LAN subinterfaced(2 WAN connections, 1 internal VLANs) and I am recieving some pretty horrible throughput when traversing the router to the WAN.

I am receiving about 2 MBPS down but around 5 up.

Currently there is a ACL on the WAN interface, and as well we are running NAT NVI.  It is possible that this might have something to do with it, but I am not sure.

Most of the CPU is going to IP input however I cannot seem to determine the cause.  One thing I am thinking is the overload for NVI is using a route-map.  Could that cause it to process switch instead of fast/CEF switch?

Any suggestions?

Thanks

[tobyarnett]

It is likely you are process switching instead of fast switching. Do a "show interface stats" and post that. Also post your relavent configs from the show run. There may be some commands you have used that are causing the router to process switch.

Toby


Sent from Cisco Technical Support Android App

[DanielSheppard]

Attaching the current running config.

FastEthernet0/0

          Switching path    Pkts In   Chars In   Pkts Out  Chars Out

               Processor    4456309 3285647619     111006   25476146

             Route cache      69216   24364696    2566772  603725410

                   Total    4525525 3310012315    2677778  629201556

FastEthernet0/1

          Switching path    Pkts In   Chars In   Pkts Out  Chars Out

               Processor     443802   61700682    3488247 3228044935

             Route cache    2720441  616285008      33163   17423382

                   Total    3164243  677985690    3521410 3245468317

Loopback0

          Switching path    Pkts In   Chars In   Pkts Out  Chars Out

               Processor          0          0     115289    6917336

             Route cache          0          0          0          0

                   Total          0          0     115289    6917336

Loopback1

          Switching path    Pkts In   Chars In   Pkts Out  Chars Out

               Processor          0          0     115305    6918300

             Route cache          0          0          0          0

                   Total          0          0     115305    6918300

NVI0

          Switching path    Pkts In   Chars In   Pkts Out  Chars Out

               Processor          0          0          0          0

             Route cache          0          0          0          0

                   Total          0          0          0          0

Tunnel0

          Switching path    Pkts In   Chars In   Pkts Out  Chars Out

               Processor     119890   10857921     120278   10874071

             Route cache     520435  406903997      81516   15006680

                   Total     640325  417761918     201794   25880751

Virtual-Access1

          Switching path    Pkts In   Chars In   Pkts Out  Chars Out

               Processor          0          0          0          0

             Route cache          0          0          0          0

                   Total          0          0          0          0

Virtual-Template1

          Switching path    Pkts In   Chars In   Pkts Out  Chars Out

               Processor          0          0          0          0

             Route cache          0          0          0          0

                   Total          0          0          0          0

Virtual-Template2

          Switching path    Pkts In   Chars In   Pkts Out  Chars Out

               Processor          0          0          0          0

             Route cache          0          0          0          0

                   Total          0          0          0          0

[Leo Laohoo]

1.  Do you have CEF enabled?  If you don't, enable.

2.  Do you have any filters enabled?  If you do, disable.

3.  Do you have any hardware VPN and is it enabled?  Use the command "sh crypto engine brief".

[tobyarnett]

Daniel,

I have reviewed your configurations and based on the fact that you have CEF running the CPU spikes are not because of your router process switching everything. One issue I did see was all of your ACL's and Policy Based Routing that you have on your router. I am sure you are in a production environment but the first chance you can, I would recommend you cutting those all the way down to just one functional test group (1 - 10 IP's that can pass in and out of your router). Your config is nice, but I think for your 1841 you are just doing too much. You may need a router with a little more power. Do a test without all of your ACL's and Route-maps and see if your throughput increases. If it does then the issue is your router is just under powered and you need a bigger model. Maybe a 3800 series. If not then we can continue troubleshooting.

-Toby