[c-nsp] 2950 Performance Problem

[Joe Baidoo]

Hi Joe,

I thought i should mention this from your switch config below, you haven't set the encapsulation type either ISL or dot1q. Check to ensure the two switches have the same native vlan and its being allowed across the two trunks. See the sript below it may be useful.

 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 400, etc ....
 switchport mode trunk 

-----Original Message-----
From: Sam Stickland [mailto:sam_ml at spacething.org]
Sent: 26 July 2004 13:33
To: Joe Goldberg
Cc: 'Ryan O'Connell'; cisco-nsp at puck.nether.net
Subject: RE: [c-nsp] 2950 Performance Problem


What is the Cisco 6509 config on the other end of the trunk?

S

On Fri, 23 Jul 2004, Joe Goldberg wrote:

> 
> Thanks for you response.  I have checked for errors on both end of the line
> and I am not seeing any.  The 6509 is set up as a simple dot1q trunk,
> nothing crazy or tricky.  I should mention though that the 6509 has an MSFC2
> in it that is doing all the VLAN routing.
> 
> As for the pings, when the 2950 gets to its max load (at least in the state
> it is now) of 12Mbps I start to drop pings of any size both to the switch
> and to servers that hang off the switch.  The servers on the switch drop
> pings outbound also.
> 
> Following your good idea, I tried putting two servers on the same vlan and
> got very good performance between the two on the same switch.  This would
> definitely point to an issue in the trunk, but I am still at a loss as to
> what that may be.
> 
> Here is just a snippet of code so you can see what I am doing on the 2950:
> 
> interface FastEthernet0/20
>  switchport access vlan 618
>  no ip address
> !
> interface FastEthernet0/21
>  switchport access vlan 617
>  no ip address
> !
> interface FastEthernet0/22
>  switchport access vlan 616
>  no ip address
> !
> interface FastEthernet0/23
>  switchport access vlan 615
>  no ip address
> !
> interface FastEthernet0/24
>  switchport mode trunk
>  no ip address
>  duplex full
>  speed 100
> 
> Thanks again for you assistance.  
> 
> Joe
> 
> -----Original Message-----
> From: Ryan O'Connell [mailto:ryan at complicity.co.uk] 
> Sent: Friday, July 23, 2004 3:18 PM
> To: Joe Goldberg
> Cc: cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] 2950 Performance Problem
> 
> Joe Goldberg wrote:
> 
> >I have a couple of 2950 switches in my data center that we are evaluating.
> >I am getting terrible performance on them.
> >  
> >
> 
> Things that spring to mind include:
> - Check for errors both ends of all links. (I.e. on the 6509 and the 
> servers as well as the 2950) I guess you already have done this, but I 
> thought I'd mention just in case. :-)
> - Try continuous pings, look for dropped packets vs. high RTT. In 
> particular, try very large pings. (2k per ping should do)
> - Try putting two ports in the same VLAN, and measure performance across 
> those two ports. This will narrow down the fault to the 2950/6509 link 
> and the 2950 itself.
> 
> 

_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/

________________________________________________________________________
This email and any files transmitted with it are confidential and
intended solely for the use of the individual or entity to whom they
are addressed. If you have received this email in error please notify
security at ffastfill.com

This email has been scanned for all viruses by the FFastFill Email
Security System.
________________________________________________________________________