Transferring 1GB file

[Ricky S]

Hey everyone, wondering if anyone has any inputs on something that's got me going in circles (literally).

I have 2 PCs both connected to a router each. Both routers are connected to each other directly via a cross-over cable. All connections are FastEthernet/auto/auto

When I transfer a 1GB file from PC A to PC B, it goes extremely slow. I clocked it at 1.11 Megabytes/sec. Entire transfer took just over 5 minutes.

Now if I remove the routers from the equation and connect both PCs to a single fastethernet switch, same file takes 1 minute to transfer at 11.8 Megabytes/sec which is more like the fastethernet speed. (100mbps / 8 = 12.5 Megabytes/sec)

I tried different cables and also checked to see if there were any errors on the ports, there were none.

Routers I am using are Cisco 1811 and Cisco 1711. PCs are connected to the built-in switch on both routers.

RouterA FastEthernet0 IP: 192.168.1.1/24

RouterA VLAN1 IP: 10.1.1.1/24

PC A IP: 10.1.1.20

RouterB FastEthernet0 IP: 192.168.1.2/24

RouterB VLAN1 IP: 10.0.0.1/24

PC B IP: 10.0.0.20

I know switching fabric is much faster than a router however it should still do better than that.  Any ideas?

Thanks all in advance

[Ricky S]

I should also add that there are no software firewalls enabled on either PCs. Only the anti-virus software is on.

[Bhishma Khanna]

Hi Ricky,

To narrow down the problem could you please try connecting the two PC's with only one router at a time and then send the file.

You may also connect the switch in between and take the wireshark captures (SPAN the port) to see what is exactly going on once you have detected the problem router.

As you have already checked the interfaces of routers, please check the router's CPU as well as memory status.

Please rate helpful posts. Thanks.

[Ricky S]

Thanks Bhishma, I'll try that out.

[Joseph W. Doherty]

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.

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Posting

An 1811 is rated at 70 Kpps but a 1711 is only rated at 13.5 Kpps.  The latter, especially, could have some "difficulty" with supporting FE thoughput.

[Ricky S]

Hi Joseph, could you please elaborate? I thought if it's a FastEthernet interface, it would atleast support 100mbps?

Thanks

[Joseph W. Doherty]

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

Ricky Sandhu wrote:
 Hi Joseph, could you please elaborate? I thought if it's a FastEthernet interface, it would atleast support 100mbps?
Thanks

A not uncommon misconception.

Many of the smaller routers do not have the capacity to support their LAN (Ethernet) interfaces for their continuous Ethernet bandwidths.  Their performance is such to support much lower WAN bandwidths.

[Ricky S]

Interesting. I didn't know that. Thanks for clearing that up.  Would you be so kind to tell me if a Cisco 2911 and  Cisco 2951 can do 100Mbps? We have several of these deployed with a lot of 100Mbps WAN circuits. It would not make sense to have routers that can't do that speed.

All these routers have GigEthernet ports so I'm assuming they should atleast be able to do 100Mbps?

We also have a 2951 sitting behind a Gigabit WAN circuit. This router is running an ISM-VPN-29 module for VPN encryption.

[Joseph W. Doherty]

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

For 100 Mbps, Cisco recommends the 3925.

See last page of the whitepaper I've attached.

[Ricky S]

Perfect. Thanks Joseph.      

[Jon Marshall]

Ricky

Just to add to the other posts.

It is unlikely but can you check your router configurations and make sure you have not disabled CEF on any of the interfaces ie. under your interface you should not have this command -

"no ip route-cache"

Jon

[Ricky S]

Hi Jon, before I setup this lab, I had done a write erase on both routers and only configured the IP addresses and static route. I'll check to see if CEF got disabled and report back.