Chapter 97 Troubleshooting Port Security - Dell PowerConnect J-EX4200-24T Software Manual

CHAPTER 97
Troubleshooting Port Security
Troubleshooting Port Security
MAC Addresses That Exceed the MAC Limit or MAC Move Limit Are Not Listed in the Ethernet
Switching Table
Problem
Solution
Multiple DHCP Server Packets Have Been Received on Untrusted Interfaces
Problem
Solution
Troubleshooting Port Security on page 2665
Troubleshooting issues for port security on J-EX Series switches:
MAC Addresses That Exceed the MAC Limit or MAC Move Limit Are Not Listed in the
Ethernet Switching Table on page 2665
Multiple DHCP Server Packets Have Been Received on Untrusted Interfaces on page 2665
You see log messages telling you that the MAC limit or MAC move limit has been exceeded,
but the specific offending MAC addresses that have been exceeding the limit are not
listed in the Ethernet switching table.
Set the MAC limit or MAC move limit action to
1.
[edit ethernet-switching-options secure-access port]
user@switch# set interface ge-0/0/2 mac-limit 5 action log
Allow some MAC address requests to come in.
2.
View the entries in the Ethernet switching table:
3.
user@switch> show ethernet-switching table
You see log messages that DHCP server packets were received on an untrusted
interface—for example:
5 untrusted DHCPOFFER received, interface ge-0/0/0.0[65], vlan v1[10] server
ip/mac 12.12.12.1/00:00:00:00:01:12 offer ip/client mac
12.12.12.253/00:AA:BB:CC:DD:01
These messages can signal the presence of a malicious DHCP server on the network.
Configure a firewall filter to block the IP address or MAC address of the malicious DHCP
server. See "Configuring Firewall Filters (CLI Procedure)" on page 2779.
log .
2665