Do DNS servers have any effect on bittorrent activity?

[nosh]

I change my DNS settings to the OpenDNS servers whenever the servers assigned by my ISP go down. I've noticed uTorrent keeps downloading even when my DNS servers are down, presumably coz I'm connected directly to some of the swarm.

I need two clarifications on this though:

1) Does a bittorrent client need a working DNS server to find new seeds/peers?

2) Does the performance of my DNS server affect my download speed? I'm asking coz I have a feeling my downloads are not as efficient when I'm using Open DNS as they are with my ISP's servers. If that's just a whim then I see no reason why I shouldn't stick with OpenDNS all the time.

[f0dder]

1) not if it caches the IP of the tracker, and the tracker doesn't change IP.

2) it shouldn't. Iirc trackers just give a list of IPs, not hostnames... many clients do perform a reverse-DNS lookup of those IPs, so connect speed can be affected - download speed isn't, though.

[nosh]

Guess I'll stick to alternating between DNSs then. Thanks.

[Ehtyar]

1) not if it caches the IP of the tracker, and the tracker doesn't change IP.

2) it shouldn't. Iirc trackers just give a list of IPs, not hostnames... many clients do perform a reverse-DNS lookup of those IPs, so connect speed can be affected - download speed isn't, though.

-f0dder (January 17, 2008, 02:46 AM)

100% agreed.

Ehtyar.