Supported Platforms
Related Documentation
- EX, QFX Series
- Enabling a Trusted DHCP Server (CLI Procedure)
- Example: Configuring Basic Port Security Features
- Example: Configuring a DHCP Server Interface as Untrusted to Protect the Switch from Rogue DHCP Server Attacks
- Monitoring Port Security
- EX Series
- Enabling a Trusted DHCP Server (J-Web Procedure)
- Troubleshooting Port Security
- QFX Series
- Enabling a Trusted Port for DHCP
Verifying That a Trusted DHCP Server Is Working Correctly
Purpose
Verify that a DHCP trusted server is working on the switch. See what happens when the DHCP server is trusted and then untrusted.
Action
Send some DHCP requests from network devices (here they are DHCP clients) connected to the switch.
Display the DHCP snooping information when the interface on which the DHCP server connects to the switch is trusted. The following output results when requests are sent from the MAC addresses and the server has provided the IP addresses and leases:
user@switch> show dhcp snooping binding
DHCP Snooping Information: MAC Address IP Address Lease Type VLAN Interface
----------------- ---------- ----- ---- ---- ---------
00:05:85:3A:82:77 192.0.2.17 600 dynamic employee—vlan ge-0/0/1.0
00:05:85:3A:82:79 192.0.2.18 653 dynamic employee—vlan ge-0/0/1.0
00:05:85:3A:82:80 192.0.2.19 720 dynamic employee—vlan ge-0/0/2.0
00:05:85:3A:82:81 192.0.2.20 932 dynamic employee—vlan ge-0/0/2.0
00:05:85:3A:82:83 192.0.2.21 1230 dynamic employee—vlan ge-0/0/2.0
00:05:85:27:32:88 192.0.2.22 3200 dynamic employee—vlan ge-0/0/2.0
Meaning
When the interface on which the DHCP server connects to the switch has been set to trusted, the output (see preceding sample) shows, for each MAC address, the assigned IP address and lease time—that is, the time, in seconds, remaining before the lease expires.
If the DHCP server had been configured as untrusted, no entries would be added to the DHCP snooping database and nothing would be shown in the output of the show dhcp snooping binding command.
Related Documentation
- EX, QFX Series
- Enabling a Trusted DHCP Server (CLI Procedure)
- Example: Configuring Basic Port Security Features
- Example: Configuring a DHCP Server Interface as Untrusted to Protect the Switch from Rogue DHCP Server Attacks
- Monitoring Port Security
- EX Series
- Enabling a Trusted DHCP Server (J-Web Procedure)
- Troubleshooting Port Security
- QFX Series
- Enabling a Trusted Port for DHCP
Published: 2013-01-17
Supported Platforms
Related Documentation
- EX, QFX Series
- Enabling a Trusted DHCP Server (CLI Procedure)
- Example: Configuring Basic Port Security Features
- Example: Configuring a DHCP Server Interface as Untrusted to Protect the Switch from Rogue DHCP Server Attacks
- Monitoring Port Security
- EX Series
- Enabling a Trusted DHCP Server (J-Web Procedure)
- Troubleshooting Port Security
- QFX Series
- Enabling a Trusted Port for DHCP
