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Lost internet speed across 2611

johnfaunce
Level 1
Level 1

A broadband speed test take before the Cisco 2611 shows 25+ Mbps. After the 2611, it drops to under 6. Consistently. The router routes between the local LAN (10.80.0.3) and a remote building across (10.13.0.2) a T1. The ADSL internet connection enters this router and leaves to a Cisco 3550 switch. Thanks for taking the time to read this. Attached is config of 2611.

2 Accepted Solutions

Accepted Solutions

Standard or enhanced, a 3550 is not usable as internet router, because it doesn't support NAT neither many other desirable Internet features.

It is a Layer 3 switch, not a router - there is a big difference.

As mentioned before, you should get a true new generation Internet router. That will be needed even when you will have fiber connection. The provider device doesn't do any of things you need your router to do.

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The Author of this posting   offers the  information contained within this posting without  consideration and with the reader's understanding that there's no     implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not  be construed as rendering  professional advice of any kind.  Usage of  this posting's information is solely at reader's own risk.

Liability Disclaimer

In    no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

From the show version of your attachment:


"Running Layer2 Switching Only Image"

Without research, don't know if that means no L3 routing is supported at all.  I would think a software feature upgrade, if available, should support L3 but if you're expecting to install newer equipment for the fiber connections you mentioned in another one of your posts, perhaps that might be your best solution.  If you can not wait, you'll either need to determine whether the 3550 can route now or be updated to do so, or replace it and/or the 2611.

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13 Replies 13

Joseph W. Doherty
Hall of Fame
Hall of Fame

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The Author of this posting  offers the  information contained within this posting without  consideration and with the reader's understanding that there's no  implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not  be construed as rendering  professional advice of any kind.  Usage of  this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising  out of the use or inability to use the posting's information even if  Author has been advised of the possibility of such damage.

Posting

A 2611 is rated at 20 Kpps, so 6 Mbps throughput is reasonable.  What's the CPU usage status look like when the 2611 is processing 6 Mbps?

Why do you have CEF switching disabled on the interfaces?

A couple of changes you might make to very, very slightly boost performance would be to disable console logging and to aggregate some of your static routes, if possible, so there's less for the router to examine.


e.g.

ip route 0.0.0.0 0.0.0.0 10.12.0.1

ip route 10.0.0.0 255.0.0.0 10.13.0.2

ip route 10.1.0.0 255.255.0.0 10.80.0.3

ip route 10.10.0.0 255.255.0.0 10.80.0.3

ip route 10.15.1.0 255.255.255.252 10.80.0.3

ip route 10.16.0.0 255.240.0.0 10.80.0.3

ip route 10.32.0.0 255.224.0.0 10.80.0.3

Thank you for the very quick reply!  Does the 20 Kpps rating mean that I can't get 25 Mbps through the 2611? The CEF was set by a third party consultant. Is there any down side to enableing it?

There is no way you can get 25 Mbps bidirectional from a 2611.

If your consultant didn't told you that, or for the reason alone the he disabled CEF, you should look for another one.

You should be looking to a 1921 or better for the job. See attachment.

Can you see a way to wire around the router - see attached?

Updated: Wrong Network Map was attached. Right one is now attached

You might, begin creative or reducing features.

In reality you always want a good router in your network. That will also allow you to eliminate other devices like consumer-class firewalls and routers, etc.

Anyway the most important thing is that get support from a reputable consultant, or certified Cisco partner.

Disclaimer

The Author of this posting   offers the  information contained within this posting without   consideration and with the reader's understanding that there's no   implied or expressed suitability or fitness for any purpose.    Information provided is for informational purposes only and should not   be construed as rendering  professional advice of any kind.  Usage of   this posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising   out of the use or inability to use the posting's information even if   Author has been advised of the possibility of such damage.

Posting


Thank you for the very quick reply!  Does the 20 Kpps rating mean that I can't get 25 Mbps through the 2611? The CEF was set by a third party consultant. Is there any down side to enableing it?

"can't get 25 Mbps", yes that what it means.  Your later network diagram shows a T1 and your 10.13.x.x network is via a serial interface, so where/how do you obtain 25 Mbps?

re: enabling CEF downside?  Generally, not compared to the benefit.

re: a later posting asking about wiring around the 2611.  Hard to say since your diagram is a bit confusing showing a loop between the 2621, 1721 and 3550.  I will note the 3550 is a L3 switch, so you can route on it.  It won't directly support a serial interface, though.

I've attached "SES Network Map2.pdf" to correct the view.

The ISP connection is the Sovernet ASDL connection at the bottom left. They upgraded the Zhome modem when they upgraded from DSL to ADSL. It is connected to X1 on the SonicWall. The SonicWall routes all X1 traffic to X0. I inserted a laptop at both Linksys switches - before and after the SonicWall to measure speed. Both read over 25 Mbps. We have 2 T1 connections in the Fairpoint data link - 2511 goes to the high school and the 1721 to Morrisville. I should have shown it as two links to Fairpoint as they are two separate T1s (I've changed the diagram to show that). So, there are two serial ports (2611 and 1721). Both are to route to other schools - low volume traffic. The Stowe Access connection (cable) is failover.

I was hoping that there would be some way to get the ASDL traffic off the 2611. I have a free network interface on the SonicWall (X3). I also have another 1721 with the same serial port available.

Thank you for your patience.

The 1721 is also a seriously outdated device.

Seems like it's time to renew your network a little.

Yes, I agree. Within the next 6 months or so, the schools will be switching to fiber - the goverment subsidized program. At that point, the fiber provider will be install their own routers to handle fiber speed.

Disclaimer

The Author of this posting  offers the  information contained within this posting without consideration and with the reader's understanding that there's no    implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not be construed as rendering  professional advice of any kind.  Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In   no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

In that case, it does look like you can use your 3550 for high speed routing.  The 3550 will very easily handle 25 Mbps.  You would then use your 2611 and 1721 for the lower volume WAN connections, which is what they were designed for.

The only issue you might have with the 3550 is whether it supports L3.  3550 are also old devices, many, if not all, in the series end-of-life.  Recall(?) they might be had with a "standard" image or an "enhanced" image.  The former is mainly for L2, but if that what's installed, it might(?) support at least static routing. If not, you might also be able to upgrade its software to L3 capability, although since the device is so old, it might be difficult to legally obtain such software.  Again, you would only need the software upgrade if existing software doesn't support any L3.

If you need to purchase a new device, you could obtain either a newer WAN router that will handle 25 Mbps, or a newer L3 switch.  For the former, a 2821, 2851 or 29xx model, should do; for the latter a 3560, even the 8 or 12 port model, should do.

Beautiful.

Attached is Show Tech Support. Can you tell if we have standard or enhanced?

Standard or enhanced, a 3550 is not usable as internet router, because it doesn't support NAT neither many other desirable Internet features.

It is a Layer 3 switch, not a router - there is a big difference.

As mentioned before, you should get a true new generation Internet router. That will be needed even when you will have fiber connection. The provider device doesn't do any of things you need your router to do.

Disclaimer

The Author of this posting   offers the  information contained within this posting without  consideration and with the reader's understanding that there's no     implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not  be construed as rendering  professional advice of any kind.  Usage of  this posting's information is solely at reader's own risk.

Liability Disclaimer

In    no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

From the show version of your attachment:


"Running Layer2 Switching Only Image"

Without research, don't know if that means no L3 routing is supported at all.  I would think a software feature upgrade, if available, should support L3 but if you're expecting to install newer equipment for the fiber connections you mentioned in another one of your posts, perhaps that might be your best solution.  If you can not wait, you'll either need to determine whether the 3550 can route now or be updated to do so, or replace it and/or the 2611.

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