6506 Core Switch Port got in Errordisable again and again .............

Dipesh Patel · ‎06-23-2008

Dear Folks,

We had old 3500 Series Switches which we have replaced last week with 2960 48 Port ehternet and 2 Gigabit Port with SFP Module.

Now I am facing the problem : The Port of CORE SW to which my one of 2960 SW is connected got in to errordisable. UDLD is enable on CORe as well UDLD enable aggressively on 2960 Gi0/1.

It's understandable that port was being errordisable if unidirectional link is there but the same link is working previously with 3500 Series SW?

Than IS there any other reason for errordisable or something need to change on 2960 SW.

2960 SW basic Config :

config terminal

username -------- password .........

enable secret ...........

enable password .......

service password-encryption

spanning-tree portfast bpduguard

int range fa0/1 - 48

spanning-tree portfast

exit

vtp mode transparent

vtp mode client

vtp domain RILHZ

clock timezone GMT 5 30

ntp server 10.2.202.52

int range gi0/1 - 2

switchport mode trunk

udld port aggressive

int vlan 1

ip address x.x.x.x y.y.y.y

exit

line vty 0 4

password ..........

no login

login local

exit

Pls suggest me ..... soon or how to troubleshoot it........???

Regards,

n.nandrekar · ‎06-23-2008

hi!

Can you look at the portfast / bpdu guard configs on both sides of the link that is going to errdisable? Portfast with bpduguard can take down a link (err disable it) if a bpdu is received on that port. Please check that portfast & bpduguard is not configured on the link between the 2900 and core switch on either side.

Regards,

Niranjan

(pls rate helpful posts)

Dipesh Patel · ‎06-24-2008

Dear Sir,

Portfast bpduguard by default is enable globaly on 2960 Sw but portfast is not enable on gi0/1 and gi0/2 Fiber port on 2960 sw.

Dipesh Patel · ‎06-25-2008

Pls do needful ...............

Subash Sharma · ‎06-26-2008

Hi,

Note that your config udld aggressive mode in 2960, so, how about other switch side, is it under aggressive mode also? Make sure the same mode is using at both side.

If so, it might be fiber strands in the cable is disconnected or just simply change a new cable to test.

By default, Port Fast is disabled on all interfaces @ 2960 Switch.

Hope this help. Thanks.

Dipesh Patel · ‎06-26-2008

Dear Sir,

My other end is 6506 L3 Switch with Cat OS and in it we have configured udld on all port i.e.

#udld

set udld enable

#module 1 : 2-port 1000BaseX Supervisor

set port trap 1/1-2 enable

set udld enable 1/1-2

set trunk 1/1 on dot1q 1-1005,1025-4094

set trunk 1/2 on dot1q 1-1005,1025-4094

set port channel 1/1-2 mode on

!

#module 2 : 2-port 1000BaseX Supervisor

set port trap 2/1-2 enable

set trunk 2/1 on dot1q 1-1005,1025-4094

set trunk 2/2 on dot1q 1-1005,1025-4094

set port channel 2/1-2 mode on

!

#module 3 : 16-port 1000BaseX Ethernet

set port trap 3/1-16 enable

set trunk 3/1 on dot1q 1-1005,1025-4094

set trunk 3/2 on dot1q 1-1005,1025-4094

set trunk 3/3 on dot1q 1-1005,1025-4094

set trunk 3/4 on dot1q 1-1005,1025-4094

set trunk 3/5 on dot1q 1-1005,1025-4094

set trunk 3/6 on dot1q 1-1005,1025-4094

set trunk 3/7 on dot1q 1-1005,1025-4094

set trunk 3/8 on dot1q 1-1005,1025-4094

set trunk 3/9 on dot1q 1-1005,1025-4094

set trunk 3/10 on dot1q 1-1005,1025-4094

set trunk 3/11 on dot1q 1-1005,1025-4094

set trunk 3/12 on dot1q 1-1005,1025-4094

set trunk 3/13 on dot1q 1-1005,1025-4094

set trunk 3/14 on dot1q 1-1005,1025-4094

set trunk 3/15 on dot1q 1-1005,1025-4094

set trunk 3/16 on dot1q 1-1005,1025-4094

set spantree portcost 3/1 3

!

#module 4 empty

!

#module 5 : 16-port 1000BaseX Ethernet

set port trap 5/1-16 enable

set udld enable 5/3-4,5/6-7

set trunk 5/1 on dot1q 1-1005,1025-4094

set trunk 5/2 on dot1q 1-1005,1025-4094

set trunk 5/3 on dot1q 1-1005,1025-4094

set trunk 5/4 on dot1q 1-1005,1025-4094

set trunk 5/15 on dot1q 1-1005,1025-4094

!

The Above is configuration for UDLD on Core SW.

On 2960 UDLD is enabled only on gi0/1 and gi0/2 Port in aggressive mode.

Portfast is enable on all port fa0/1 - 48

portfastbpdugurd is enable default mode i.e globally.

FO cable is same as before when old 3500 series SW is working. But after migrating sw i.e 2960 this proble occurs.

And avg response of all 2960 sw is also slow now.

So pls suggest me the solution.

If u need any data from me pls .....

Dipesh Patel · ‎06-26-2008

May It be due to Flapping...........???