Oracle Connection taking long time to establish / tnsping taking too long

1) Check listener.log size

At 10g, D:\oracle\product\10.2.0\db_1\NETWORK\log

At 11g, D:\app\Administrator\diag\tnslsnr\apex11-PC\listener\trace

2) If listener.log size is in GBs then

a) Stop listener services

b) Rename listener.log

c) Start listener services

lsnrctl>show

lsnrctl>set Log_status off

rename Listener.log to listenerold.log (from the command prompt)

lsnrctl>set Log_Status on

it will start listener.log automatically

3) Tnsping

ping

tracert

tnsping