08-18-2014 09:40 AM - edited 03-07-2019 08:25 PM
Hi all,
We have a P2P 100 Mb link between our Datacenters. Connection is terminated on 2960 stack switch on both ends. The configuration on the switch is normal. Today the switch port has gone down. We tot its ISP problem, but after some time we have shut and no shut which made the connection up.
Now i want to know is this UDLD or other problem which caused the link down. There are no logs related to this.
Please suggest any config if you have
Config on switch#################
interface GigabitEthernet2/0/25
switchport access vlan 45
switchport mode access
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
queue-set 2
priority-queue out
mls qos trust dscp
spanning-tree portfast
end
Logs#################
Aug 18 13:09:49.034: %LINK-5-CHANGED: Interface GigabitEthernet2/0/25, changed state to administratively down
Version#####
Cisco IOS Software, C2960X Software (C2960X-UNIVERSALK9-M), Version 15.0(2)EX3, RELEASE SOFTWARE (fc1)
System image file is "flash:/c2960x-universalk9-mz.150-2.EX3.bin"
Regards,
Satya.M
08-18-2014 10:05 AM
Hi Satya,
Syslog from both sides devices during time of issue would help to check what triggered the link down.
Regards,
Akash
08-18-2014 10:09 AM
Akash you are right, but have removed syslog on that day for some server issue.
Let me know if you know any in general config for a P2P link with fiber termination on switch.
Regards,
Satya.M
08-21-2014 07:32 PM
Hi Satya,
So far it looks like that port went to errordisabled mode and that is why it was down and shut/no-shut helped to recover it. Since this fiber connectivity is provided by ISP and transmission is involved There could be below possible reasons when port may go to error disable state
- UDLD
- Link was flapping continuously
- Loopback error
There are other reasons also, you can refer below link
http://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/69980-errdisable-recovery.html
Once link is down due to errdisable, to recover it you need to perform shut/no-shut even though root problem is resolved. Or you should have errdisable recovery should be enabled.
cat6knative#show errdisable recovery ErrDisable Reason Timer Status ----------------- -------------- udld Disabled bpduguard Disabled security-violatio Disabled channel-misconfig Disabled pagp-flap Disabled dtp-flap Disabled link-flap Disabled l2ptguard Disabled psecure-violation Disabled gbic-invalid Disabled dhcp-rate-limit Disabled mac-limit Disabled unicast-flood Disabled arp-inspection Disabled Timer interval: 300 seconds
cat6knative(Config)#errdisable recovery cause bpduguard
cat6knative#show errdisable recovery ErrDisable Reason Timer Status ----------------- -------------- udld Disabled bpduguard Enabled <<<<<<<<<<<<<<<< security-violatio Disabled channel-misconfig Disabled pagp-flap Disabled dtp-flap Disabled link-flap Disabled l2ptguard Disabled psecure-violation Disabled gbic-invalid Disabled dhcp-rate-limit Disabled mac-limit Disabled unicast-flood Disabled arp-inspection Disabled Timer interval: 300 seconds
cat6knative(Config)#errdisable recovery interval 400
Regards,
Akash
08-18-2014 12:25 PM
Hello
do you have udld enabled?
what does the log buffer show?
do you have errdisable recovery enable for udld?
show udld intx/x
show interface x/x status
show interface status err-disabled
show logg
res
Paul
08-19-2014 01:58 AM
Hi Paul....tnx for your reply. Plz find the outputs.
sw#sh udld gigabitEthernet 2/0/25
Interface Gi2/0/25
---
Port enable administrative configuration setting: Follows device default
Port enable operational state: Disabled
Current bidirectional state: Unknown
sw#sh interfaces gigabitEthernet 2/0/25 status
Port Name Status Vlan Duplex Speed Type
Gi2/0/25 ** P2P-BRDC-CHALFO connected 45 a-full a-1000 1000BaseSX SFP
sw#sh interfaces status err-disabled
sw#
Aug 18 10:48:59.079: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet2/0/25, changed state to down
Aug 18 10:49:00.079: %LINK-3-UPDOWN: Interface GigabitEthernet2/0/25, changed state to down
Regards,
Satya.M
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide