Disabling NTP on an Interface
By default, NTP is enabled on all active interfaces. If you disable NTP on an interface, Dell Networking OS drops any NTP packets sent to
that interface.
To disable NTP on an interface, use the following command.
•
Disable NTP on the interface.
INTERFACE mode
ntp disable
To view whether NTP is configured on the interface, use the
show config
command in INTERFACE mode. If
ntp disable
is not
listed in the
show config
command output, NTP is enabled. (The
show config
command displays only non-default configuration
information.)
Configuring a Source IP Address for NTP Packets
By default, the source address of NTP packets is the IP address of the interface used to reach the network.
You can configure one interface’s IP address include in all NTP packets.
To configure an IP address as the source address of NTP packets, use the following command.
•
Configure a source IP address for NTP packets.
CONFIGURATION mode
ntp source
interface
Enter the following keywords and slot/port or number information:
•
For a 1-GigabitEthernet interface, enter the keyword
GigabitEthernet
then the slot/port information.
•
For a 10-Gigabit Ethernet interface, enter the keyword
TenGigabitEthernet
then the slot/port information.
•
For a Loopback interface, enter the keyword
loopback
then a number from 0 to 16383.
•
For a port channel interface, enter the keywords
port-channel
then a number.
•
For a VLAN interface, enter the keyword
vlan
then a number from 1 to 4094.
To view the configuration, use the
show running-config ntp
command in EXEC privilege mode (refer to the example in
Configuring NTP Authentication
NTP authentication and the corresponding trusted key provide a reliable means of exchanging NTP packets with trusted time sources.
NTP authentication begins when the first NTP packet is created following the configuration of keys. NTP authentication in Dell Networking
OS uses the message digest 5 (MD5) algorithm and the key is embedded in the synchronization packet that is sent to an NTP time source.
Dell Networking OS Behavior
: Dell Networking OS uses an encryption algorithm to store the authentication key that is different from
previous Dell Networking OS versions; Dell Networking OS uses data encryption standard (DES) encryption to store the key in the startup-
config when you enter the
ntp authentication-key
command. Therefore, if your system boots with a startup-configuration from an
Dell Networking OS version in which you have configured
ntp authentication-key
, the system cannot correctly decrypt the key
and cannot authenticate the NTP packets. In this case, re-enter this command and save the running-config to the startup-config.
To configure NTP authentication, use the following commands.
1
Enable NTP authentication.
850
System Time and Date
Summary of Contents for S3048-ON
Page 1: ...Dell Configuration Guide for the S3048 ON System 9 11 2 5 ...
Page 137: ...0 Gi 1 1 Gi 1 2 rx Flow N A N A 0 0 No N A N A yes Access Control Lists ACLs 137 ...
Page 142: ...Figure 10 BFD Three Way Handshake State Changes 142 Bidirectional Forwarding Detection BFD ...
Page 241: ...Dell Control Plane Policing CoPP 241 ...
Page 287: ... RPM Synchronization GARP VLAN Registration Protocol GVRP 287 ...
Page 428: ...Figure 53 Inspecting the LAG Configuration 428 Link Aggregation Control Protocol LACP ...
Page 477: ...Figure 73 Configuring Interfaces for MSDP Multicast Source Discovery Protocol MSDP 477 ...
Page 478: ...Figure 74 Configuring OSPF and BGP for MSDP 478 Multicast Source Discovery Protocol MSDP ...
Page 483: ...Figure 77 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 483 ...
Page 484: ...Figure 78 MSDP Default Peer Scenario 3 484 Multicast Source Discovery Protocol MSDP ...
Page 745: ...Figure 104 Single and Double Tag TPID Match Service Provider Bridging 745 ...
Page 746: ...Figure 105 Single and Double Tag First byte TPID Match 746 Service Provider Bridging ...