The internet on my mac keeps slowing down and I'm struggling to diagnose the problem. Other identical machines on the same network aren't suffering from the same problem. After a reboot the internet (and pings) is all quick and normal, but after a few hours or days things start to crawl. When pinging an address (using network utility) it takes a good 10-15 seconds for the first response. When it eventually gets started, all the response times are very good (even the first one!). It just takes a long time to initiate. What could cause this, and how could I go about diagnosing things further?
I'm connected via Wi-Fi and the transmit rate is always a consistent 300mbps.
Ping has started… [10-15 second delay...] PING zdnet.com (18.104.22.168): 56 data bytes 64 bytes from 22.214.171.124: icmp_seq=0 ttl=50 time=173.677 ms 64 bytes from 126.96.36.199: icmp_seq=1 ttl=50 time=173.075 ms 64 bytes from 188.8.131.52: icmp_seq=2 ttl=50 time=173.530 ms 64 bytes from 184.108.40.206: icmp_seq=3 ttl=50 time=172.780 ms 64 bytes from 220.127.116.11: icmp_seq=4 ttl=50 time=176.745 ms 64 bytes from 18.104.22.168: icmp_seq=5 ttl=50 time=173.354 ms
I've noticed that if a webpage is taking a very long time to load and I flush the DNS cache, some or all of the page then loads normally, but any subsequent page loads still takes ages. If I keep flushing the cache ever 2 seconds then the things load okay. Very odd!