GarrettCom MNS-6K-SECURE 14.1.4 Switch User Manual


 
MAGNUM 6K SWITCHES, MNS-6K USER GUIDE
intervention. Most administrators prefer to use static IP addresses (which are allocated out for
such purposes) instead of using the manual mode.
Allocating specific IP address for specific networks or VLANs also aids in securing the network.
Firewall rules or access rules can be written and designed for specific address ranges, which are
allocated out by the DHCP server. Since the allocation is automated and controlled, the network
manager can leverage this automation for security automation as well.
Technical Details
Since the DHCP client evolved from BOOTP, the DHCP protocol uses the same two IANA
assigned ports as BOOTP: 67/udp for the server side, and 68/udp for the client side. For DHCP
to function across a firewall (including those on PCs or end devices) it is important to “unblock”
or “allow” these ports to be used by the device.
DHCP operations fall into four basic operations. These operations are
1) IP lease request
2) IP lease offer
3) IP lease selection and
4) IP lease acknowledgement.
These operations are shown in the figure below.
DHCP Discovery
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