¿Hay alguna manera de desactivar las búsquedas inversas y dejar activadas las búsquedas directas?
Resumen:
Usar no domain-lookup
bajo line vty 0 4
...
Detalles:
Tiene razón, el comportamiento predeterminado es realizar y almacenar en caché una búsqueda directa / inversa de las direcciones en los comandos show. Esta configuración comienza de manera similar a la tuya ...
Comportamiento de referencia: búsquedas directas / inversas
HotCoffee#clear host *
HotCoffee#sh runn | i ip domain|ip name|^ +domain|NTP
Time source is NTP, 06:10:42.327 CDT Tue Aug 13 2013
ip domain name pennington.net
ip name-server 172.16.1.5
domain-name pennington.net
HotCoffee#
Después de borrar el caché del host, no hay entradas en él ...
HotCoffee#show host
Load for five secs: 0%/0%; one minute: 1%; five minutes: 1%
Time source is NTP, 06:11:46.864 CDT Tue Aug 13 2013
Default domain is pennington.net
Name/address lookup uses domain service
Name servers are 172.16.1.5
Codes: UN - unknown, EX - expired, OK - OK, ?? - revalidate
temp - temporary, perm - permanent
NA - Not Applicable None - Not defined
Host Port Flags Age Type Address(es)
HotCoffee#
Al hacer show user
o se ping
llena el caché del host ...
HotCoffee#sh user
Line User Host(s) Idle Location
* 66 vty 0 cisco idle 00:00:00 tsunami.pennington.net
Interface User Mode Idle Peer Address
HotCoffee#ping flame
Translating "flame"...domain server (172.16.1.5)
Translating "flame"...domain server (172.16.1.5) [OK]
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.1, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 1/2/4 ms
HotCoffee#
Ahora hay entradas de host para el ping
objetivo y show user
...
HotCoffee#sh hosts
Load for five secs: 1%/0%; one minute: 0%; five minutes: 0%
Time source is NTP, 06:16:32.811 CDT Tue Aug 13 2013
Default domain is pennington.net
Name/address lookup uses domain service
Name servers are 172.16.1.5
Codes: UN - unknown, EX - expired, OK - OK, ?? - revalidate
temp - temporary, perm - permanent
NA - Not Applicable None - Not defined
Host Port Flags Age Type Address(es)
tsunami.pennington.net None (temp, OK) 0 IP 172.16.1.5
flame.pennington.net None (temp, OK) 0 IP 172.16.1.1
flame None (temp, UN) 0 IPv6
HotCoffee#
Solución: solo búsquedas directas
Use no domain-lookup
debajo de las líneas vty / console para restringir el comportamiento de IOS a solo búsquedas directas ...
HotCoffee#conf t
Enter configuration commands, one per line. End with CNTL/Z.
HotCoffee(config)#line vty 0 4
HotCoffee(config-line)#no domain-lookup
HotCoffee(config-line)#end
HotCoffee#
Primero borro el caché del host para una prueba limpia ...
HotCoffee#clear host *
HotCoffee#
HotCoffee#
show user
anteriormente realizaba una búsqueda inversa en 172.16.1.5, además de rellenar el caché del host, pero ahora tampoco sucede ...
HotCoffee#sh user
Load for five secs: 1%/0%; one minute: 0%; five minutes: 0%
Time source is NTP, 06:20:00.250 CDT Tue Aug 13 2013
Line User Host(s) Idle Location
* 66 vty 0 cisco idle 00:00:00 172.16.1.5 <----
Interface User Mode Idle Peer Address
HotCoffee#
HotCoffee#sh host
Load for five secs: 2%/0%; one minute: 0%; five minutes: 0%
Time source is NTP, 06:20:06.729 CDT Tue Aug 13 2013
Default domain is pennington.net
Name/address lookup uses domain service
Name servers are 172.16.1.5
Codes: UN - unknown, EX - expired, OK - OK, ?? - revalidate
temp - temporary, perm - permanent
NA - Not Applicable None - Not defined
Host Port Flags Age Type Address(es)
<----
HotCoffee#
Solo para mostrar que las búsquedas directas todavía funcionan ...
HotCoffee#
HotCoffee#ping flame
Translating "flame"...domain server (172.16.1.5)
Translating "flame"...domain server (172.16.1.5) [OK]
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
HotCoffee#
HotCoffee#
HotCoffee#
HotCoffee#sh hosts
Load for five secs: 0%/0%; one minute: 0%; five minutes: 0%
Time source is NTP, 06:25:43.237 CDT Tue Aug 13 2013
Default domain is pennington.net
Name/address lookup uses domain service
Name servers are 172.16.1.5
Codes: UN - unknown, EX - expired, OK - OK, ?? - revalidate
temp - temporary, perm - permanent
NA - Not Applicable None - Not defined
Host Port Flags Age Type Address(es)
tsunami.pennington.net None (temp, OK) 0 IP 172.16.1.5
flame.pennington.net None (temp, OK) 0 IP 172.16.1.1
flame None (temp, UN) 0 IPv6
HotCoffee#