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New Member

weird 3750 stack ,

our client have a c3750-stack by using the stack-wise cable,, there is 6 c3750 stack as 1 switch. we enable the port-security in all the ports for user. the problem is the port random erri-diabled by the mac-address. this mac-address actully learn from another port. for example, f2/0/24 is erri-disable,casue this is by aaaa.aaaa.aaaa,, and this mac-address actully learned from f5/0/43.

after I sh/no-sh the port ,, the port is back to normal.but few hours later,, this thing happened again , and this time ,it is another 2 port involved in.

need help from you guys

1 ACCEPTED SOLUTION

Accepted Solutions
New Member

Re: weird 3750 stack ,

We had a similar problem and as part of an additional ssh problem we installed the latest IOS (122-50.SE). Fixed ssh and the problem you mention above.

4 REPLIES
New Member

Re: weird 3750 stack ,

Need more info from you..

1. what is the current aging time set for port-security?

2. For the mac-addresses in conflict that's shutting down the port, what device is it? Laptop?

3. Do you have "sticky" option enabled? From what you described, I think not, but I just to make sure. Don't enable "sticky" option unless you've a real business needs for it.

4. Is it the same mac-add that has been causing the problem or different mac-addresses every time?

5. Sounded like the problem arose after you implemented port-security, is it correct?

6. Can you post the switchport config?

Good luck.

New Member

Re: weird 3750 stack ,

thanks for your reply

here is the information:

1. what is the current aging time set for port-security?

it is default setting

2. For the mac-addresses in conflict that's shutting down the port, what device is it? Laptop?

yes,,ladtop,,some of them running VM

3. Do you have "sticky" option enabled? From what you described, I think not, but I just to make sure. Don't enable "sticky" option unless you've a real business needs for it.

no,we don't enable that feature

4. Is it the same mac-add that has been causing the problem or different mac-addresses every time?

no, it is random mac-address.

5. Sounded like the problem arose after you implemented port-security, is it correct?

no, we have run this stack for 3 weeks, and this issue just came last weekend.

6. Can you post the switchport config?

just for example,portf1/0/24

int f1/0/24

sw mo acc

sw acc vlan 74

sw port

sw port max 1

sw port violation restrict

spanning portfast

spanning bpduguard enable

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

thx

New Member

Re: weird 3750 stack ,

We had a similar problem and as part of an additional ssh problem we installed the latest IOS (122-50.SE). Fixed ssh and the problem you mention above.

New Member

Re: weird 3750 stack ,

finnaly , we catched the bad guy,, who is act as a bad dhcp server,,but thanks guys

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