ZyXEL UAG715 User Guide - Page 139

Interface Parameters, DHCP Settings

Page 139 highlights

Chapter 8 Interfaces Interface Parameters The UAG restricts the amount of traffic into and out of the UAG through each interface. • Egress bandwidth sets the amount of traffic the UAG sends out through the interface to the network. • Ingress bandwidth sets the amount of traffic the UAG allows in through the interface from the network.1 If you set the bandwidth restrictions very high, you effectively remove the restrictions. The UAG also restricts the size of each data packet. The maximum number of bytes in each packet is called the maximum transmission unit (MTU). If a packet is larger than the MTU, the UAG divides it into smaller fragments. Each fragment is sent separately, and the original packet is re-assembled later. The smaller the MTU, the more fragments sent, and the more work required to re-assemble packets correctly. On the other hand, some communication channels, such as Ethernet over ATM, might not be able to handle large data packets. DHCP Settings Dynamic Host Configuration Protocol (DHCP, RFC 2131, RFC 2132) provides a way to automatically set up and maintain IP addresses, subnet masks, gateways, and some network information (such as the IP addresses of DNS servers) on computers in the network. This reduces the amount of manual configuration you have to do and usually uses available IP addresses more efficiently. In DHCP, every network has at least one DHCP server. When a computer (a DHCP client) joins the network, it submits a DHCP request. The DHCP servers get the request; assign an IP address; and provide the IP address, subnet mask, gateway, and available network information to the DHCP client. When the DHCP client leaves the network, the DHCP servers can assign its IP address to another DHCP client. In the UAG, some interfaces can provide DHCP services to the network. In this case, the interface can be a DHCP relay or a DHCP server. As a DHCP relay, the interface routes DHCP requests to DHCP servers on different networks. You can specify more than one DHCP server. If you do, the interface routes DHCP requests to all of them. It is possible for an interface to be a DHCP relay and a DHCP client simultaneously. As a DHCP server, the interface provides the following information to DHCP clients. 1. At the time of writing, the UAG does not support ingress bandwidth management. UAG715 User's Guide 139

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Chapter 8 Interfaces
UAG715 User’s Guide
139
Interface Parameters
The UAG restricts the amount of traffic into and out of the UAG through each interface.
Egress bandwidth sets the amount of traffic the UAG sends out through the interface to the
network.
Ingress bandwidth sets the amount of traffic the UAG allows in through the interface from the
network.
1
If you set the bandwidth restrictions very high, you effectively remove the restrictions.
The UAG also restricts the size of each data packet. The maximum number of bytes in each packet
is called the maximum transmission unit (MTU). If a packet is larger than the MTU, the UAG divides
it into smaller fragments. Each fragment is sent separately, and the original packet is re-assembled
later. The smaller the MTU, the more fragments sent, and the more work required to re-assemble
packets correctly. On the other hand, some communication channels, such as Ethernet over ATM,
might not be able to handle large data packets.
DHCP Settings
Dynamic Host Configuration Protocol (DHCP, RFC 2131, RFC 2132) provides a way to automatically
set up and maintain IP addresses, subnet masks, gateways, and some network information (such
as the IP addresses of DNS servers) on computers in the network. This reduces the amount of
manual configuration you have to do and usually uses available IP addresses more efficiently.
In DHCP, every network has at least one DHCP server. When a computer (a DHCP client) joins the
network, it submits a DHCP request. The DHCP servers get the request; assign an IP address; and
provide the IP address, subnet mask, gateway, and available network information to the DHCP
client. When the DHCP client leaves the network, the DHCP servers can assign its IP address to
another DHCP client.
In the UAG, some interfaces can provide DHCP services to the network. In this case, the interface
can be a DHCP relay or a DHCP server.
As a DHCP relay, the interface routes DHCP requests to DHCP servers on different networks. You
can specify more than one DHCP server. If you do, the interface routes DHCP requests to all of
them. It is possible for an interface to be a DHCP relay and a DHCP client simultaneously.
As a DHCP server, the interface provides the following information to DHCP clients.
1.
At the time of writing, the UAG does not support ingress bandwidth management.