07-03-2007 03:29 AM - edited 03-05-2019 05:06 PM
Hello
Kindly;examine the attached File....
Why we have duplicate mac address ?
10xs
07-03-2007 03:34 AM
Hi Ali
What is gigabit 0/1 - is it a trunk link to another switch ?
Jon
07-03-2007 03:36 AM
Hi
What is the configuration of this ports i mean r they trunk ports or access ports.
Thanks
Mahmood
07-03-2007 03:39 AM
Hello
no access Port...
10xs
07-03-2007 03:41 AM
Ali
What is attached to this port ?
Jon
07-03-2007 03:46 AM
Hi ,
I also observed it on my 3750 switch (L3)...
different mac-address are assigned to same interface...
copy the mac-address and do the sh arp | in mac-address for g0/1. Do it for all mac-addresses ..you will get the exact IP for only one mac-address, not for all...
pl clear mac-address table and check the issue...
I observed that when there is a fluctuation or flap in network we will get this type of output.
cheers :)
satish
07-03-2007 03:51 AM
Hello
normal Pc attached to this Port
10xs
07-03-2007 06:07 AM
I seriouslt think the link in question is a trunk.
Satish, i have not seen this type of behavior on the 3750 switch. You will multiple mac-addresses on the port connecting to a router and also a SVI configured on the switch for the same subnet.
The ouput on the other hand shows mac-addresses and that too in different vlans which should be possible only when the link is a trunk
can you post output of sh int g0/1 switchport
Narayan
07-03-2007 09:09 AM
Hello!
Sorry this is a Trunk port...
sh int g0/1
GigabitEthernet0/1 is up, line protocol is up
Hardware is Gigabit Ethernet, address is 0002.b9b8.cd31 (bia 0002.b9b8.cd31)
Description: To xxxx
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Auto-duplex (Full), link type is autonegotiation, media type is SX
output flow-control is off, input flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 6961000 bits/sec, 7683 packets/sec
5 minute output rate 61000 bits/sec, 62 packets/sec
152984413 packets input, 1546610108 bytes, 0 no buffer
Received 117454707 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 74766732 multicast, 0 pause input
29242288 packets output, 381330967 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 pause output
0 output buffer failures, 0 output buffers swapped out
NoW its become Clear,can i know the Reason and How to Solve This?
10xs
07-03-2007 09:17 AM
Since the trunk port is connected to another switch, it will learn all the mac-address from the downstream switch on that port.
say if you have a router connected to switchA and has a trunk connection to switchB, then switchA should know all the mac addresses for the nodes on switchB for forwarding frames that are sent from the router to these devices
HTH, rate if it does
Narayan
07-03-2007 09:30 AM
Narayan
is there any Problem;why only this mac relearning 3 Times ON THE Same Interface.I Think its is a unnormal Behavior.reexamine the attached File
10xs
07-03-2007 09:26 AM
Hi Ali,
How are you !!
Could you please try clearing the mac-address table using " clear mac-address table " command and check if still shows the same mac in different vlans on the trunk port. One of the reason for this would be if there is a user who is connecting his PC in different switchports which belongs to different vlan, then the same mac-address might be see on the different vlans
HTH,
-amit singh
07-03-2007 09:32 AM
amit My Freind How r You;Hope You Doing well.Say Hello Ankur i miss him so much...
07-03-2007 09:35 AM
Hi Ali, I am fine and doing well.. How are you doing.. I will pass on your message to Ankur. he is very busy now a days..
Did you clear the mac-address table ? Check and update us on the status.
-amit singh
07-03-2007 10:36 AM
Hello amit!
if so;How can i trace the Ip Address for this PC.e.g How can i know its ip address..
10xs amit
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: