[c-nsp] 2950 Performance Problem

[Marcelo Maraboli]

Joe.

check the "default vlan" or "native vlan" setting on the
6509 port connected to the 2950. Also check this on the 2950.

I had a similar problem and they where different...

Also check the "allowed Vlans" per port on both switches.

regards,

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.
> 

-- 
Marcelo Maraboli Rosselott
Jefe Area de Redes           (Network & UNIX Systems Administrator)
Ingeniero Civil Electronico                   (Electronic Engineer)

Direccion Central de Servicios Computacionales (DCSC)
Universidad Tecnica Federico Santa Maria, Chile.
phone: +56 32 654237
mailto:marcelo.maraboli at dcsc.utfsm.cl	http://elqui.dcsc.utfsm.cl/