BinTec X3200, Руководство пользователя

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X3200 User’s Guide 233
Basic IP settings
6
Exchanging DNS Addresses with WAN Partners
IP Control Protocol
(IPCP)
The same applies if dynamic negotiation of name servers is activated for the IP
configuration of a WAN partner and X3200 is operating in Server Mode
(Dynamic Name Server Negotiation =
server (send)). In this case, the ad-
dresses of the global name servers or the address of X3200 itself can also be
sent for name server negotiations via IPCP to the WAN partner, who is the IP
address client.
If X3200 is operating in Client Mode (Dynamic Name Server Negotiation =
client (receive)), name server addresses can if necessary be negotiated with the
WAN partner, who is the IP address server, and sent to X3200 . These can be
entered as global name servers in X3200 and are thus available for future name
resolutions.
Strategy for Name Resolution in X3200
A DNS request is handled by X3200 as follows:
1. Can the request be answered directly from the static or dynamic cache (IP
address or negative answer)?
– If yes, the information is forwarded.
– If no, see 2.
2. Is a matching forwarding entry available?
In this case, the relevant DNS are asked. If the connection to the WAN part-
ner is not active, an attempt is made to set it up.
– If a DNS can resolve the name, the information is forwarded and a dy-
namic entry created in the cache.
– If none of the DNS asked can resolve the name or no matching for-
warding entry is available, see 3.
3. Are global name servers entered?
In this case, the relevant DNS are asked. If the IP address of X3200 or the
loopback address is entered for local applications, these are ignored here.
– If a DNS can resolve the name, the information is forwarded and a dy-
namic entry created in the cache.
– If none of the DNS asked can resolve the name or no static name serv-
ers are entered, see 4.