Cisco Switch 2950 Problem.

[dreynolds20]

Hi,

I am new to the world of switches and I have three Cisco 2950 Switches.

The problem is that when I have workstations plugged in to the switches everything works fine but when the computer goes to sleep and I wake it up it actually drops the connection and reconnects at 10mb and eventually 100mb but the user has about thrity seconds of inactivity before they can start work again.

I have forced the port on the switch and the card onto 100mb full duplex but the problem seems to still be happening.

Cheers

Dave

 

[vipergg]

Put the following command on each of the client ports on the 2950, what you are seeing is spanning tree going thru it's calculation and this will eliminate that .
Command --- "switchport host" .

 

[vipergg]

PS, do not use the command on connecting links between switches .

 

[dreynolds20]

I have just tried that and it does not work.

I have attached a copy of my config file for your perusal.

Thanks for your help.

Cisco01#show conf
Using 2503 out of 32768 bytes
!
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Cisco01
!
enable secret 5 $1$ac1F$jELWeTJ2DN9ho4ULdlZBg1
enable password ics1grp2uk3
!
ip subnet-zero
!
!
spanning-tree mode pvst
no spanning-tree optimize bpdu transmission
spanning-tree extend system-id
!
!
!
!
interface FastEthernet0/1
description test
switchport mode access
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/2
description test1
switchport mode access
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/3
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/4
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/5
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/6
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/7
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/8
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/9
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/10
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/11
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/12
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/13
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/14
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/15
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/16
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/17
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/18
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/19
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/20
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/21
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/22
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/23
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/24
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/1
!
interface GigabitEthernet0/2
!
interface Vlan1
no ip address
no ip route-cache
shutdown
!
ip http server
!
line con 0
line vty 0 4
password ics1
login
line vty 5 15
password ics1
login
!
!
end

 

[Lequang]

DOn't set 'auto-negaciate'on host and Switch.

If the negaciation fail you will drop down to 10mb and probably less than.

So set 'auto detect' on PC.

 

[vipergg]

If you set auto detect on the pc , it "MUST" be set as auto on the switch also , otherwise you will get a speed and duplex mismatch . If the pc is auto then the switch has to be auto also . Besides that I don't see anything out of the ordinary on the switch config . Client , switch has to be either auto/auto on both ends or you have to hardcode the speed and duplex to match on each end .

 

[Lequang]

That's theory. But when negociation is not good then speed will goes down and network problems appears.
Often negociate is ok when the devices belonng to the same brand. With 2 different brand , you have to be very carefull ...
That what I just want to tell.

 

[chieftan999]

Quick question. Why are you running Switchport mode access?

I thought you would only require this for VLAN seperation?


Reamin positive. The affect on those around you will amaze.

 

[Cluebird]

chieftain999,

FYI by default Cisco switchports are dynamic ports. That means they will try to form trunks or EtherChannels automatically if there is another switch plugged into the port. Dynamic Trunking Protocol (DTP) and Port Aggregation Protocol (PAgP) add overhead on top of the Spanning-Tree Protocol (STP). When connecting hosts to these ports, best practice is to turn off DTP, PAgP, and STP with the interface command "switchport host". With one command you implement portfast (which disables STP on the port) and turn off DTP and PAgP. Another suggestion is to enable bpduguard so the port will errdisable if someone accidently plugs another switch into the access port.

It used to be best practice to hard code switchports with speed and duplex but now we teach leave AUTO since certain NICs (3COM) require the autonegotiation or they won't work. Personally, I find the "it depends" answer is best because you need to get a result and if AUTO works, do it, if hard code works, do it. Know your gear and the quirks of the NICs you're connecting to the switch.

HTH.