Currently, when
acting as a DNS client, an S3100 series Ethernet switch supports both static and
dynamic domain name resolution.
1.1.1 display
dns domain
Syntax
display dns domain [ dynamic ]
View
Any view
Parameters
dynamic: Displays
DNS suffixes dynamically assigned through DHCP or other protocols.
Description
Use the display dns domain command
to display the DNS suffixes.
Related commands: dns domain.
Examples
# Display DNS suffixes
<Sysname> display dns domain
No Domain-name
0 aaa.com
Table 1-1
Description on the fields of the display dns
domain command
|
Field
|
Description
|
|
No
|
Sequence number
|
|
Domain-name
|
DNS suffix
|
1.1.2 display dns dynamic-host
Syntax
display dns dynamic-host
View
Any view
Parameters
None
Description
Use the display dns dynamic-host command
to display the information in the dynamic domain name cache.
Examples
# Display the information in the dynamic
domain name cache.
<Sysname> display dns
dynamic-host
No Domain-name --->
Ipaddress TTL Alias
1 lm.test.h3c 172.1.223.1
3564
No Domain-name <---
Ipaddress TTL Alias
1 aaaa 172.1.223.2
3594
Table 1-2
Description on the fields of the display dns
dynamic-host command
|
Field
|
Description
|
|
No
|
Sequence number
|
|
Domain-name
|
Domain name
|
|
Ipaddress
|
IP address of the corresponding domain
name
|
|
TTL
|
Time for which an entry is cached in
seconds.
|
|
Alias
|
Alias for the domain name. There can be four
aliases at most.
|
|
--->
<---
|
DNS resolution has two types:
Forward resolution: domain name--->IP address
Reverse resolution: IP address--->domain name
|
1.1.3 display
dns server
Syntax
display dns server [ dynamic ]
View
Any view
Parameters
dynamic: Displays
the DNS Server information dynamically obtained through DHCP or other protocols.
Description
Use the display dns server command to
display the DNS Server information.
Related commands: dns server.
Examples
# Display the DNS Server information.
<Sysname> display dns server
Type:
D:Dynamic S:Static
IPv4 DNS Servers :
Domain-server Type IP Address
1 S 192.168.0.4
IPv6 DNS Servers :
Table 1-3 Description on the fields of
the display dns server command
|
Field
|
Description
|
|
Type
|
Type of the DNS server. S indicates the
DNS server is specified manually, while D indicates the DNS server
information is obtained dynamically through DHCP or other protocols.
|
|
IPv4 DNS Servers
|
IPv4 DNS server
|
|
IPv6 DNS Servers
|
IPv6 DNS server
|
|
Domain-server
|
Number of the DNS server, which is
assigned automatically by the system and starts from 1. Such numbering for
IPv4 DNS servers is independent of that for IPv6 ones.
|
For details about
IPv6 DNS, refer to IPv6 Management Command.
1.1.4 display ip host
Syntax
display ip host
View
Any view
Parameters
None
Description
Use the display ip host command to
display mappings between host names and IP addresses in the static DNS database.
Examples
# Display mappings between host names and
IP addresses in the static DNS database.
<Sysname> display ip host
Host
Age Flags Address
host.com
0 static 192.168.0.38
Table 1-4
Description on the fields of the display ip host
command
|
Field
|
Description
|
|
Host
|
Host name
|
|
Age
|
Time to live. 0 means that a static entry
is never outdated.
You can only manually remove the mappings
between host names and IP addresses.
|
|
Flags
|
Indicates the type of mappings between host
names and IP addresses, static or dynamic
Static indicates static mapping between host
names and IP addresses
|
|
Address
|
IP address of a host
|
1.1.5 dns domain
Syntax
dns domain domain-name
undo dns domain [ domain-name ]
View
System view
Parameters
domain-name:
DNS suffix, a string of 1 to 60 characters which can be letters, numbers,
hyphens (-), underscores (_), and dots (.).
Description
Use the dns domain command to
configure a DNS suffix. The system can automatically add the suffix to part of the
domain name you entered for resolution.
Use the undo dns domain command to
delete the configured DNS suffix.
No DNS suffix is configured by default.
You can configure a maximum of 10 DNS
suffixes. You must enter the DNS suffix before deleting it. Otherwise, all configured
DNS suffixes are deleted.
Related commands: display dns domain.
The DNS feature
supported by S3100 series Ethernet switches should be used together with a DNS
server. DNS implementations vary with DNS servers. For example, S3100 serial
Ethernet switches support a domain name containing “_”, while a
Windows 2000 Server may not be able to resolve the domain name.
Examples
# Configure com as a DNS suffix.
<Sysname> system-view
System View: return to User View with
Ctrl+Z.
[Sysname] dns domain com
Syntax
dns resolve
undo dns resolve
View
System view
Parameters
None
Description
Use the dns resolve command to enable
dynamic domain name resolution.
Use the undo dns resolve command to
disable dynamic domain name resolution.
Dynamic domain name resolution is disabled
by default.
Examples
# Enable dynamic domain name resolution.
<Sysname> system-view
System View: return to User View with
Ctrl+Z.
[Sysname] dns resolve
1.1.7 dns
server
Syntax
dns server ip-address
undo dns server [ ip-address ]
View
System view
Parameters
ip-address:
IP address of the DNS Server.
Description
Use the dns server command to configure
an IP address for the DNS Server.
Use the undo dns server to remove the
IP address of the DNS server.
No IP address is configured for the DNS server
by default.
You can configure a maximum of 6 DNS servers,
including those with IPv6 addresses.
Related commands: display dns server.
Examples
# Configure 172.16.1.1 for a DNS Server.
<Sysname> system-view
System View: return to User View with
Ctrl+Z.
[Sysname] dns server 172.16.1.1
Syntax
ip host hostname
ip-address
undo ip host
hostname [ ip-address ]
View
System view
Parameters
hostname:
Host name, a string of 1 to 20 characters which can be letters, numbers, hyphens
(-), or dots (.). The host name must include at least one letter.
ip-address: IP
address of the specified host, in dotted decimal notation.
Description
Use the ip host command to create a
mapping between host name and IP address in the static DNS database.
Use the undo ip host command to
remove the mapping.
No mappings are created by default.
Each host name can correspond to only one
IP address. When IP addresses are configured for the same host for multiple
times, only the IP address configured last time is valid.
Related commands: display ip host.
Examples
# Configure IP address 10.110.0.1 for host
aaa.
<Sysname> system-view
System View: return to User View with
Ctrl+Z.
[Sysname] ip host aaa 10.110.0.1
Syntax
nslookup type { ptr ip-address | a domain-name }
View
Any view
Parameters
ptr ip-address:
Displays the corresponding domain name for an IP address.
a domain-name: Displays the corresponding IP address for a DNS
domain name. A domain name is a string of up to 30 characters. Automatic domain
name addition is supported.
Description
Use the nslookup type command to display
DNS resolution result, namely, the domain name for a specified IP address or IP
address for a specified domain name.
Examples
# Display the corresponding domain name for
192.168.3.2.
<Sysname> nslookup type ptr 192.168.3.2
Trying DNS server (10.72.66.36)
Name: www.host.com
Address: 192.168.3.2
# Display the corresponding IP address for
www.host.com.
<Sysname> nslookup type a www.host.com
Trying DNS server (10.72.66.36)
Name: www.host.com
Address: 192.168.3.2
Syntax
reset dns dynamic-host
View
User view
Parameters
None
Description
Use the reset dns dynamic-host
command to clear information in the dynamic domain name cache.
Related commands: display dns
dynamic-host.
Examples
# Clear the information in the dynamic
domain name cache.
<Sysname> reset dns
dynamic-host
