Switch Issue[urgent ]

Unanswered Question
Jan 19th, 2009
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Dear All,


I am getting the below erros messages, could some one help me in fixing up this issue


logs pasted below


09-01-19 12:15:16 Local1.Alert 172.24.11.3 %RTD-1-ADDR_FLAP: FastEthernet0/23 relearning 30 addrs per min

2009-01-19 12:15:17 Local1.Alert 172.24.11.5 %RTD-1-ADDR_FLAP: FastEthernet0/1 relearning 30 addrs per min

2009-01-19 12:16:16 Local1.Alert 172.24.11.3 %RTD-1-ADDR_FLAP: FastEthernet0/23 relearning 30 addrs per min

2009-01-19 12:16:17 Local1.Alert 172.24.11.5 %RTD-1-ADDR_FLAP: FastEthernet0/1 relearning 30 addrs per min

2009-01-19 12:17:16 Local1.Alert 172.24.11.3 %RTD-1-ADDR_FLAP: FastEthernet0/23 relearning 30 addrs per min

2009-01-19 12:17:17 Local1.Alert 172.24.11.5 %RTD-1-ADDR_FLAP: FastEthernet0/1 relearning 30 addrs per min

2009-01-19 12:18:16 Local1.Alert 172.24.11.3 %RTD-1-ADDR_FLAP: FastEthernet0/23 relearning 30 addrs per min

2009-01-19 12:18:17 Local1.Alert 172.24.11.5 %RTD-1-ADDR_FLAP: FastEthernet0/1 relearning 30 addrs per min

2009-01-19 12:19:16 Local1.Alert 172.24.11.3 %RTD-1-ADDR_FLAP: FastEthernet0/23 relearning 30 addrs per min

2009-01-19 12:19:17 Local1.Alert 172.24.11.5 %RTD-1-ADDR_FLAP: FastEthernet0/1 relearning 30 addrs per min



Adhitya

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mahmoodmkl Mon, 01/19/2009 - 04:33
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Hi


The messages u r seeing is of STP Loop check for the redundant links in u r network and disable one of them and check for the issues that caused this.


Thanks

Mahmood

glen.grant Mon, 01/19/2009 - 05:04
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I agree someone has physically looped those 2 ports together . Also do a show cdp neighbor and see if the switch sees itself on both of those ports. For some reason spanning did not take care of the loop .

adhityakarthik Mon, 01/19/2009 - 05:10
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Dear All


Thanks very much for all who replied quickly


Please note that i am not configuring any ether channel


2) Chekced HSRP and found perfectly working fine




Note:These both ports are both trunk ports

could suggest me more on this


regards

Adhitya

pkpatel Mon, 01/19/2009 - 09:58
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Please post output of "sh cdp nei".


Also post running config for both ports.

adhityakarthik Tue, 01/20/2009 - 01:42
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hi


Please find the output of cdp ne and runing config of ports



Fas 0/17 161 R S I Cisco 2851Gig 0/0.1

SEP00152B1761AB Fas 0/3 175 H Cisco IP PPort 1

SEP0014A9EF0382 Fas 0/8 175 H Cisco IP PPort 1

SEP0014A9CB2187 Fas 0/16 175 H Cisco IP PPort 1

SEP0014A9EDF50A Fas 0/12 175 H Cisco IP PPort 1

SEP0014A98186DB Fas 0/21 145 H Cisco IP PPort 1

SEP0014A9CB238B Fas 0/23 175 H Cisco IP PPort 1

SEP0014A98BCA67 Fas 0/6 175 H Cisco IP PPort 1

SEP0014A9D9C99F Fas 0/11 175 H Cisco IP PPort 1

SEP00152BA21DF1 Fas 0/5 175 H Cisco IP PPort 1

SEP0014A9EF0A89 Fas 0/7 130 H Cisco IP PPort 1

SEP0014A9CB257D Fas 0/9 145 H Cisco IP PPort 1

SEP00152B483CEE Fas 0/2 175 H Cisco IP PPort 1

RS-01 Gig 0/1 164 T S WS-C3524-XGig 0/1

RS-01 Fas 0/1 163 T S WS-C3524-XFas 0/1

DR-02 Fas 0/23 132 T S WS-C3524-XFas 0/1

DR-03 Fas 0/23 155 T S WS-C3524-XFas 0/1

172.24.11.3#sh run int fa0/23

Building configuration...


Current configuration:

!

interface FastEthernet0/23

switchport trunk encapsulation dot1q

switchport mode trunk

no snmp trap link-status

end

--------------------------------------


Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater


Device ID Local Intrfce Holdtme Capability Platform Port ID

SEP0014A9CB2382 Fas 0/23 161 H Cisco IP PPort 1

SEP0014A9EDD7E5 Fas 0/11 120 H Cisco IP PPort 1

SEP00152B23BD39 Fas 0/7 131 H Cisco IP PPort 1

SEP0014A9CB238B Fas 0/1 131 H Cisco IP PPort 1

SEP0004f2e05103 Fas 0/22 143 H Cisco IP Cport 1

SEP0014A9EDF391 Fas 0/9 160 H Cisco IP PPort 1

SEP0014A9CB261B Fas 0/6 160 H Cisco IP PPort 1

DR-04 Fas 0/2 132 T S WS-C3524-XFas 0/1

-DR-01 Fas 0/1 168 T S WS-C3524-XFas 0/23

-DR-02 Fas 0/1 148 T S WS-C3524-XFas 0/1

DR-03#sh run int fa0/1

Building configuration...


Current configuration:

!

interface FastEthernet0/1

switchport trunk encapsulation dot1q

switchport mode trunk

no snmp trap link-status

end



Please guide me


Adhitya

Giuseppe Larosa Tue, 01/20/2009 - 02:47
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Hello Adhitya,


likely someone has inserted an hub in your network see


RS-01 Fas 0/1 163 T S WS-C3524-XFas 0/1

DR-02 Fas 0/23 132 T S WS-C3524-XFas 0/1

DR-03 Fas 0/23 155 T S WS-C3524-XFas 0/1


you say the two ports f0/1 and f0/23 are trunk ports but we see two CDP neighbors on your fas0/23 this is possible only if an hub or a non Cisco switch is connected to fas0/23 and the two devices DR-02 and DR-03 are then connected to it.

Another device RS-01 is connected to port fas0/1 but here you see only one neighbor.


probably the three switches RS-01, DR-02 and DR-03 are also connected between them


Verify what is connected to your fas0/23 in the switch receiving the error messages if necessary modify the cabling so that you see only one neighbor out port fas0/23


Hope to help

Giuseppe



mlund Tue, 01/20/2009 - 04:41
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Hi


In addition to what Giuseppe found, also this can be something.

From your first cdp output the 7:th entry is

SEP0014A9CB238B Fas 0/23

and from second cdp output the 4:th entry is

SEP0014A9CB238B Fas 0/1

it seems that this is the device which is shortcutting the ports.


/Mikael

l.mourits Tue, 01/20/2009 - 05:37
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In addition to that, and together with the other details I would think someone plugged the PC-port of the IPphone (SEP0014A9CB238B ) into a hub or non cisco switch, where the switch has an uplink to the network as well.


Unplug the PC-port of the IPphone (SEP0014A9CB238B ) and the loop should be gone.


adhityakarthik Wed, 01/21/2009 - 02:41
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Hi all


Thanks very much to all for supporting


as suggested in the previous post i have removed the deviceSEP0014A9CB238B from the network but still loop occurs

could some one help


regards

Adhitya

dabels Wed, 01/21/2009 - 14:52
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after removing the phone from the port please do a show cdp nei detail would like to see more information on the device that is attached to this port....

adhityakarthik Fri, 01/23/2009 - 03:33
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Dear All


Please find the our put after removing the phone



DR-01#sh run int fa0/23

Building configuration...


Current configuration:

!

interface FastEthernet0/23

switchport trunk encapsulation dot1q

switchport mode trunk

no snmp trap link-status

end


DR-01#sh cdp n

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater


Device ID Local Intrfce Holdtme Capability Platform Port ID


Fas 0/17 137 R S I Cisco 2851Gig 0/0.1

SEP00152B1761AB Fas 0/3 146 H Cisco IP PPort 1

SEP0014A9EF0382 Fas 0/8 146 H Cisco IP PPort 1

SEP0014A9CB2187 Fas 0/16 146 H Cisco IP PPort 1

SEP0014A9EDF50A Fas 0/12 146 H Cisco IP PPort 1

SEP0014A98186DB Fas 0/21 176 H Cisco IP PPort 1

SEP0014A98BCA67 Fas 0/6 146 H Cisco IP PPort 1

SEP0014A9D9C99F Fas 0/11 146 H Cisco IP PPort 1

SEP00152BA21DF1 Fas 0/5 146 H Cisco IP PPort 1

SEP0014A9EF0A89 Fas 0/7 146 H Cisco IP PPort 1

SEP0014A9CB257D Fas 0/9 176 H Cisco IP PPort 1

SEP00152B483CEE Fas 0/2 146 H Cisco IP PPort 1

RS-01 Gig 0/1 127 T S WS-C3524-XGig 0/1

RS-01 Fas 0/1 126 T S WS-C3524-XFas 0/1

DR-02 Fas 0/23 122 T S WS-C3524-XFas 0/1

DR-03 Fas 0/23 154 T S WS-C3524-XFas 0/1

DR-01#



2 Switch

Jan 23 11:29:31: %RTD-1-ADDR_FLAP: FastEthernet0/1 relearning 30 addrs per min

Jan 23 11:30:31: %RTD-1-ADDR_FLAP: FastEthernet0/1 relearning 30 addrs per min

DR-03# sh run int fa0/1

Building configuration...


Current configuration:

!

interface FastEthernet0/1

switchport trunk encapsulation dot1q

switchport mode trunk

no snmp trap link-status

end


DR-03#sh cdp n

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater


Device ID Local Intrfce Holdtme Capability Platform Port ID

SEP0014A9CB2382 Fas 0/23 170 H Cisco IP PPort 1

SEP0014A9EDD7E5 Fas 0/11 173 H Cisco IP PPort 1

SEP00152B23BD39 Fas 0/7 140 H Cisco IP PPort 1

SEP0004f2e05103 Fas 0/22 159 H Cisco IP Cport 1

SEP0014A9EDF391 Fas 0/9 151 H Cisco IP PPort 1

SEP0014A9CB261B Fas 0/6 170 H Cisco IP PPort 1

DR-04 Fas 0/2 171 T S WS-C3524-XFas 0/1

DR-01 Fas 0/1 145 T S WS-C3524-XFas 0/23

DR-02 Fas 0/1 176 T S WS-C3524-XFas 0/1

DR-03#


mlund Fri, 01/23/2009 - 03:56
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Hi


As Giuseppe already pointed out, there still seems to be some kind of equipment(hub) connected between DR01, DR02 and DR03.


DR-01#sh cdp n

|

|

DR-02 Fas 0/23 122 T S WS-C3524-XFas 0/1

DR-03 Fas 0/23 154 T S WS-C3524-XFas 0/1


DR-03#sh cdp n

|

|

DR-01 Fas 0/1 145 T S WS-C3524-XFas 0/23

DR-02 Fas 0/1 176 T S WS-C3524-XFas 0/1


If you can provide us with a drawing, showing us how things are connected will help us understand.

Or do sh cdp ne also on RS01, DR02 and DR04


/Mikael



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