Overview Of Dns Relay; Configuring Dns Relay - Ericsson HM210DP/DI User Manual

9.2

Overview of DNS Relay

When you specify the HM210dp/di's LAN port IP address as the DNS
address, then the device automatically performs "DNS relay"; i.e. because
the device itself is not a DNS server, it forwards domain name lookup
requests it receives from the LAN PCs to a DNS server at the ISP. It then
relays the DNS server's response to the PC.
When performing DNS relay, the HM210dp/di must maintain the IP
addresses of the DNS servers it contacts. It can learn these addresses in
either or both of the following ways:
9.3

Configuring DNS Relay

Follow these steps to configure DNS Relay:
EN/LZT 108 6492 R2 - October 2003
Learned through PPP;
If the device uses a PPP connection to the ISP, the primary and
secondary DNS addresses can be learned via the PPP protocol. To
use this method, the "Use DNS" checkbox must be selected in the
PPP interface properties.
Using this option provides the advantage that you will not need to
reconfigure the PCs or the HM210dp/di if the ISP changes their
DNS addresses.
Configured on the HM210dp/di;
You can use the device's DNS feature to specify the ISP's DNS
addresses. If the device also uses a PPP interface with the "Use
DNS" property enabled, then these configured addresses will be
used in addition to the two addresses learned through PPP. If "Use
DNS" is not enabled, or if a protocol other than PPP is used (such
as EoA), then these configured addresses will be used as the
primary and secondary DNS addresses.
1. Configure the LAN PCs as DHCP clients of the HM210dp/di.
2. Go to LAN > DHCP Server, enter the LAN IP address (e.g.
192.168.1.1) or 0.0.0.0 as the DNS address in the DHCP server
pool.
By default, 0.0.0.0 is already set as the DNS of the DHCP pool.
3. Determine how the HM210dp/di will learn the DNS server address:
Option 1 – Using a PPP connection to learn the DNS
Use DNS must be enabled in the PPP interface properties. Go to
Routing > PPP and check the PPP interface details:
Configuring DNS Server Addresses
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