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New Member

VLANs trunking performance issue

Hi,

I have 5 Catalysts (3550, 3750, ...) sharing 4 vlans by using trunking ports. If I do a transfer (FTP, ...) which has to pass through one trunk, then the bandwidth is very low (< 300 kbit/s).

Is this "bandwidth reduction" normal?

If not, could I expect to have a 100 Mbit/s performance in the trunk.

Thank you very much for your help.

Rgds,

Bastien

7 REPLIES
Silver

Re: VLANs trunking performance issue

Did you checked the application side (e.g. ftp program) ? Is it the application problem ?

Did you tested the application w/o using trunking ?

Could you please provide the port status of the slow performance and any packet drop during FTP ?

New Member

Re: VLANs trunking performance issue

I have tried many other applications and the performance remains the same.

The applications were also tested directly on a VLAN on one switch and the performance were great (standard).

Basically all the ports are fixed to 100/Full and no packets are dropped.

Any other checks that I could do?

Thanks a lot,

Bastien

New Member

Re: VLANs trunking performance issue

In answer to your question no it's not mormal, Have you checked the speed/duplex settings of the ports?

If they are ok 100/full from your original post, can you please post a show interface from both the trunk link interfaces and the interfaces with the FTP client and server

Regards

N

Re: VLANs trunking performance issue

can you jus post the configuration of the switch, so that will get some idea.

New Member

Re: VLANs trunking performance issue

Hi,

The port assignments are:

Cat3550, port 0/13: FTP Server

Cat3550, port 0/24: Trunk VLAN200

Cat2960, port 0/22: trunk VLAN200

Cat2960, port 0/12: FTP Client

I remarked that when I do the FTP transfer, the port where the FTP Client is connected to is blinking yellow/orange, and stops blinking when the transfer is interrupted (stays yellow).

Please find attached the "sh int" for the ports involved (captured after a transfer).

We can see some input errors on Cat2960 port 0/12 but nothing on the others interfaces.

Would you also like the conf of the two switches?

Thank you for your time and help.

Bastien

New Member

Re: VLANs trunking performance issue

Please find attached the conf file for the two switches.

Thank you,

Bastien

New Member

Re: VLANs trunking performance issue

Bastien,

Have you confirmed the speed and duplex settings on the FTP client machine?

With the switch port set to 100/full the NIC card will also need to be set as well to avoid the card possibly defaulting to half duplex.

No collisions will show on the switch port as these will be detected and handled by the PC NIC.

Regards

N

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