05-02-2005 04:43 AM - edited 03-02-2019 10:38 PM
Hi,
we have a problem with our new cisco 2970(SW2).
Our topology is like this:
dslam
|
|
R1-sw1-sw2-sw3-R2
|
|R3
R3
The DSLAM and R3 are connected to sw2.
We rebooted our dslam and the dslam terminates 200 VLANS.
between the reboot we couldn't reach the Customers on gi0/5 and gi0/6. sw3 and r2 were also unreachable. In the logs was nothing written, only that gi0/25 was down and up. What could be the Problem?
I will try it with the command spanning-tree portfast trunk on the Port gi0/25, so that the UP/down event are not annonced to the spanning-tree instance, but i don't know if it will help. I haven't seen such a behavior.
We use the IOS: Version 12.2(20)SE4
Any comments are welcome.
Attached is the configuration of the Switch.
version 12.2
no service pad
service tcp-keepalives-in
service tcp-keepalives-out
service timestamps debug datetime msec localtime
service timestamps log datetime msec localtime
service password-encryption
no service dhcp
!
hostname sw2
!
no logging console
aaa new-model
aaa authentication login default local
spanning-tree mode rapid-pvst
no spanning-tree optimize bpdu transmission
spanning-tree extend system-id
!
!
interface GigabitEthernet0/1
description sw1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 2-4094
switchport mode trunk
speed 100
duplex full
!
!
!
interface GigabitEthernet0/5
desc Customer1
switchport access vlan 235
switchport mode access
!
interface GigabitEthernet0/5
desc Customer2
switchport access vlan 30
switchport mode access
!
interface GigabitEthernet0/25
description DSLAM
switchport trunk encapsulation dot1q
switchport trunk native vlan 50
switchport trunk allowed vlan 2-4094
switchport mode trunk
!
interface GigabitEthernet0/26
description sw2
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 2-4094
switchport mode trunk
!
05-02-2005 08:54 PM
There is not enough info to start with. You say you could not reach the switch, but from where were you trying to access the switch ?
05-03-2005 01:11 AM
Hi,
i was behind r1 and everything behind sw2 was unreachable also the direct connected customers on sw2.
At the same time i was able to telnet so sw2 but i couldn't see any errors or log entries.
I think it has something to do with spanning-tree, but i don't know what, because there was no loop and also no wrong BPDU.
Maybe it is somthing else.
Sw3 is a extreme switch, after the reboot of our dslam, i connected to it and showed in the logs, there wasn't a interface flap nor a spanning-tree event.
cu thomas
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