J-Web Configuration

Select Configuration>View and Edit>Edit Configuration.
The Configuration page appears.
Next to Applications, click Configure or Edit.
Next to Application, click Add new entry.
In the Application name box, type host-unreachable.
From the ICMP type list, select Enter specific value.
In the Number box, type 5.
From the ICMP code list, select Enter specific value.
In the Number box, type 0 and click OK.
To specify the inactivity timeout, corresponding to the application name host-unreachable, click Edit.
In the Inactivity timeout box, type 4 and click OK.
If you are finished configuring the device, commit the configuration.