Big wifi problem here too. Before 10.10.2 I had some problems with wifi... now I got a lot of problems! The wifi connection with my router works for just some seconds and then it stops working.
I'm trying to ping it and this is the output:
PING 192.168.1.1 (192.168.1.1): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
Request timeout for icmp_seq 2
Request timeout for icmp_seq 3
Request timeout for icmp_seq 4
Request timeout for icmp_seq 5
Request timeout for icmp_seq 6
Request timeout for icmp_seq 7
Request timeout for icmp_seq 8
Request timeout for icmp_seq 9
Request timeout for icmp_seq 10
Request timeout for icmp_seq 11
Request timeout for icmp_seq 12
Request timeout for icmp_seq 13
Request timeout for icmp_seq 14
Request timeout for icmp_seq 15
Request timeout for icmp_seq 16
Request timeout for icmp_seq 17
Request timeout for icmp_seq 18
I clicked on the wifi icon on the menu bar and then…
64 bytes from 192.168.1.1: icmp_seq=19 ttl=254 time=304.193 ms
64 bytes from 192.168.1.1: icmp_seq=20 ttl=254 time=118.855 ms
64 bytes from 192.168.1.1: icmp_seq=21 ttl=254 time=111.553 ms
64 bytes from 192.168.1.1: icmp_seq=22 ttl=254 time=3.927 ms
64 bytes from 192.168.1.1: icmp_seq=23 ttl=254 time=82.132 ms
64 bytes from 192.168.1.1: icmp_seq=24 ttl=254 time=2.070 ms
--- 192.168.1.1 ping statistics ---
26 packets transmitted, 6 packets received, 76.9% packet loss
round-trip min/avg/max/stddev = 2.070/103.788/304.193/101.026 ms
I've discovered that, when there's no connection, if I click in the wifi icon on the menu bar, it reconnect and works for some seconds, then it drops again.
my hardware:
router: D-Link DSL-2640R
computer: iMac late 2013
Alessandro
PS: with iPhone, iPad, PC and another older iMac the connection works…