shaping on interface vlan !

Answered Question
Jul 7th, 2008

hi all, i am faced with a very strange issue, ( i nearly pull my hairs out ), see i have a 1841 router with HWIC-4ESW installed. on Fa 0/0/0 i have a ADSL connection so i gave ip to int vlan 1 and my link is active now. my task is to limit ALL the traffic exiting from Vlan 1 (or Fa0/0/0) to 256 kbits/sec. Now this is my config

policy-map Shape-all-256

class class-default

shape average 256000

int vlan 1

service-policy output Shape-all-256

Now when i run show policy int vlan 1

it shows me that packets are being matched. see below


Service-policy output: Shape-all-256

Class-map: class-default (match-any)

37126 packets, 42189762 bytes

30 second offered rate 320000 bps, drop rate 0 bps

Match: any

Traffic Shaping

now see the offered rate its 320000bps means 320 kpbs and it rises !!

see this

sh int vlan 1

30 second output rate 685000 bits/sec, 73 packets/sec

Why is this so ?? i tried all this combination

1) i applied it on Fa0/0/0 but no use

2) in place of shape average i tried following 2 combinations as well

1) shape average 256000 32000 0

2) shape peak 256000 32000 0

but NO USE AT ALL :-(, i m in the middle of something big so kindly help me out pls, do shaping doesnt work with int vlan ?? or am i doing something wrong ?

kindly help me out

I have this problem too.
0 votes
Correct Answer by Nagendra Kumar ... about 8 years 3 months ago

Hi rox,

Either you have to install HWIC-1FE or You have only rate-limit option.



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Overall Rating: 5 (1 ratings)
illusion_rox Mon, 07/07/2008 - 02:31

Thanks Nagendra, thanks alot, now kindly tell me wat to do in this case, kindly help me achieve my goal

i want to shape all traffic to 256 kbits and then apply CBWFQ so that my server traffic gets 128 kbps while others may get the rest. Now this is the config i have done successfully on my normal layer 3 Fastethernet ports

Class-map Server-Traffic-in

Match access-group name Server_Traffic

Policy-map Server-Traffic

Class Server-Traffic-in

Bandwidth 128

Class class-default

Bandwidth 64

Policy-map Shape-all-256

Class class-default

Shape average 256000

Service-policy Server-Traffic

Now as we know that i cant apply this on an SVI so wat to do now to achieve this goal ?

Thanks alot for prompt response

Nagendra Kumar ... Mon, 07/07/2008 - 03:56


Can you please explain why you need to shape traffic at your LAN interface?. From your description, I understand HWIC-4ESW is your LAN side and ADSL is your WAN side. Normally shaping will be enabled at your WAN side.

If you need to limit your traffic at your LAN side, the only option I can see is rate-limit.



illusion_rox Mon, 07/07/2008 - 20:30

Dear Nagendra, this is my scenario

on 1841 you know that we have to Fa interfaces, on Fa 0/1 i have LAN, on Fa 0/0 i have Wimax link, and now to accomodate redundant link via ADSL we have plugged it in HWIC-4ESW, now as you know that link between ADSL modem is 10/100 Base T, where is the CIR is 256 kb, so in order to apply my qos i need to first shape the traffic to meet this CIR,

I hope you get an idea, kindly guide me how to do it

Nagendra Kumar ... Mon, 07/07/2008 - 23:58

As you have to connect ADSL modem, I feel HWIC-4ESW is not the one you need to use. You may have to use HWIC-1FE. This is a routed port interface and this supports shaping.



illusion_rox Tue, 07/08/2008 - 00:46

Dear Nagendra, we already have 100+ branches that are already using HWIC-4ESW, so we cant change it to 1FE !!, does it mean i am hanged up ??

Correct Answer
Nagendra Kumar ... Tue, 07/08/2008 - 04:53

Hi rox,

Either you have to install HWIC-1FE or You have only rate-limit option.



quipugmbh Tue, 07/22/2008 - 23:20

Hi Rox,

I have faced the same problem, having HWIC-4ESW and not being able to do QOS.

What i have done is like this, i connecte F0/1 of the router directly to the HWIC-4ESW, in this way you can see it like having the HWIC-4ESW as an outside switch, on fast 0/1 you configure now subinterfaces, it is also good to create a VRF and put all ports of the hwic-4esw on that vrf in this way you divide the switch completely from the global routing and arp table, do not create vlan interfaces.

After all this in subinterfaces you can apply QOS.

Let me know if it is not clear enough.

best regards



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