ZyXEL Communications ISG50 User Manual

 Chapter 12 Interfaces

ISG50 User’s Guide

Connectivity Check

The ISG50 can regularly check the connection to the gateway you specified to make 
sure it is still available. You specify how often to check the connection, how long to wait 
for a response before the attempt is a failure, and how many consecutive failures are 
required before the ISG50 stops routing to the gateway. The ISG50 resumes routing to 
the gateway the first time the gateway passes the connectivity check.

Enable 

Connectivity 

Check

Select this to turn on the connection check.

Check Method

Select the method that the gateway allows. 

Select icmp to have the ISG50 regularly ping the gateway you specify to make sure it is 
still available. 

Select tcp to have the ISG50 regularly perform a TCP handshake with the gateway you 
specify to make sure it is still available. 

Check Period

Enter the number of seconds between connection check attempts.

Check Timeout

Enter the number of seconds to wait for a response before the attempt is a failure.

Check Fail 

Tolerance

Enter the number of consecutive failures before the ISG50 stops routing through the 
gateway.

Check Default 

Gateway

Select this to use the default gateway for the connectivity check.

Check this 

address

Select this to specify a domain name or IP address for the connectivity check. Enter that 
domain name or IP address in the field next to it.

Check Port

This field only displays when you set the Check Method to tcp. Specify the port 
number to use for a TCP connectivity check.

DHCP Setting

The DHCP settings are available for the OPT, LAN and DMZ interfaces.

DHCP

Select what type of DHCP service the ISG50 provides to the network. Choices are:

None - the ISG50 does not provide any DHCP services. There is already a DHCP server 
on the network.

DHCP Relay - the ISG50 routes DHCP requests to one or more DHCP servers you 
specify. The DHCP server(s) may be on another network.

DHCP Server - the ISG50 assigns IP addresses and provides subnet mask, gateway, 
and DNS server information to the network. The ISG50 is the DHCP server for the 
network.

The following fields appear if the ISG50 is a DHCP Relay.

Relay Server 1

Enter the IP address of a DHCP server for the network.

Relay Server 2

This field is optional. Enter the IP address of another DHCP server for the network.

The following fields appear if the ISG50 is a DHCP Server.

IP Pool Start 

Address

Enter the IP address from which the ISG50 begins allocating IP addresses. If you want 
to assign a static IP address to a specific computer, click Add Static DHCP.

If this field is blank, the Pool Size must also be blank. In this case, the ISG50 can 
assign every IP address allowed by the interface’s IP address and subnet mask, except 
for the first address (network address), last address (broadcast address) and the 
interface’s IP address.

Configuration > Network > Interface > VLAN > Edit (continued)