[c-nsp] 2950 Performance Problem

[Joe Goldberg]

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.

-- 
         Ryan O'Connell - CCIE #8174
<ryan at complicity.co.uk> - http://www.complicity.co.uk

I'm not losing my mind, no I'm not changing my lines,
I'm just learning new things with the passage of time